TS-7553-V2

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Revision as of 14:01, 2 March 2017 by Kris (talk | contribs) (→‎MicroSD Card: Updated for TS-7553-V2 Rev. B)
Note: The TS-7553-V2 is currently in engineering sample phase. This means software and features are very likely to change as the TS-7553-V2 is currently under heavy development. There may also be some features that are currently not implemented or not fully tested, please see the Revisions and changes for more information.


TS-7553-V2
File:Ts-7553-V2.jpg
Product Page
Documentation
Schematic
Mechanical Drawing
FTP Path
Processor
NXP/Freescale i.MX6ul
528MHz or 696MHz
i.MX6ul Product Page
CPU Documentation

Overview

Note: This product has not been released as a standard product at this time. Information contained within this manual may be incorrect and is subject to change. Additionally, the software currently available for the TS-7553-V2 has not been finalized and is subject to change at any time

The TS-7553-V2 has not been officially released as a standard product, it is currently in engineering sampling phase. This is a small embedded platform with an NXP/Freescale i.MX6ul 528 MHz or 696 MHz CPU with 512 MB DDR3 RAM.

Getting Started

A Linux PC is recommended for development, and will be assumed for this documentation. For users in Windows or OSX we recommend virtualizing a Linux PC. Most of our platforms run Debian and if there is no personal distribution preference this is what we recommend for ease of use.

Virtualization

Suggested Linux Distributions

It may be possible to develop using a Windows or OSX system, but this is not supported. Development will include accessing drives formatted for Linux and often Linux based tools.

Booting up the board

WARNING: Be sure to take appropriate Electrostatic Discharge (ESD) precautions. Disconnect the power source before moving, cabling, or performing any set up procedures. Inappropriate handling may cause damage to the board.

The TS-7553-V2 has an input voltage range of 5 V to 28 V DC through the main power connector which offers screw terminals for secure wiring or a barrel jack. The TS-7553-V2 will require approximately 1.4 W at idle. An ideal power supply for the TS-7553-V2 will allow up to 5W to allow peripherals to be powered as well.

Once you have applied power you should look for console output. The first output is from the bootrom: 

U-Boot 2016.03-14510-gf8f09c6 (Feb 16 2017 - 16:25:11 -0800)

CPU:   Freescale i.MX6UL rev1.1 at 396 MHz
Reset cause: WDOG
Board: Technologic Systems TS-7553-V2
I2C:   ready
DRAM:  512 MiB
MMC:   FSL_SDHC: 0, FSL_SDHC: 1
Net:   FEC0 [PRIME]
Booting from the SD card ...
** File not found /boot/boot.ub **
32618 bytes read in 56 ms (568.4 KiB/s)
6735792 bytes read in 438 ms (14.7 MiB/s)
Kernel image @ 0x80800000 [ 0x000000 - 0x66c7b0 ]
## Flattened Device Tree blob at 83000000
   Booting using the fdt blob at 0x83000000
   Using Device Tree in place at 83000000, end 8300af69

Starting kernel ...


Welcome to Debian GNU/Linux 8 (jessie)!

[ SKIP ] Ordering cycle found, skipping D-Bus System Message Bus Socket
         Expecting device dev-ttymxc0.device...
[  OK  ] Reached target Remote File Systems (Pre).
...
[  OK  ] Started Update UTMP about System Runlevel Changes.

Debian GNU/Linux 8 ts-imx6ul ttymxc0

ts-imx6ul login:

The U-Boot build date reflects when U-Boot was built and serves as a revision indicator. A change to the kernel or filesystem will not affect this date.

Get a Console

Serial Console

The TS-7553-V2 includes a USB device port, this uses a 8051 based microcontroller to create a serial device on a host PC. The serial console is provided through this port at 115200 baud, 8n1, with no flow control.

Console from Linux

There are many serial terminal applications for Linux, three common used applications are picocom, screen, and minicom. These examples demonstrate all three applications and assume that the serial device is "/dev/ttyUSB0" which is common for USB adapters. Be sure to replace the serial device string with that of the device on your workstation.

picocom is a very small and simple client. 

sudo picocom -b 115200 /dev/ttyUSB0

screen is a terminal multiplexer which happens to have serial support. 

sudo screen /dev/ttyUSB0 115200

Or a very commonly used client is minicom which is quite powerful but requires some setup: 

sudo minicom -s
  • Navigate to 'serial port setup'
  • Type "a" and change location of serial device to "/dev/ttyUSB0" then hit "enter"
  • If needed, modify the settings to match this and hit "esc" when done:
     E - Bps/Par/Bits          : 115200 8N1
     F - Hardware Flow Control : No
     G - Software Flow Control : No
  • Navigate to 'Save setup as dfl', hit "enter", and then "esc"

Console from Windows

Putty is a small simple client available for download here. Open up Device Manager to determine your console port. See the putty configuration image for more details.

Device Manager Putty Configuration


U-Boot

Note: These sections are incomplete at this time.

This platform includes U-Boot as the bootloader to load and boot the full operating system. The i.MX6UL processor loads U-Boot from the eMMC flash at power-on. U-Boot allows booting images from the microSD, eMMC, NFS, or USB. U-Boot is a general purpose bootloader that is capable of booting into common Linux distributions, Android, QNX, or others.

On a normal boot, output from U-Boot will be similar to the following: 

U-Boot 2016.03-00305-g75344a5 (Dec 15 2017 - 13:53:14 -0800)

CPU:   Freescale i.MX6UL rev1.1 at 396 MHz
Reset cause: WDOG
Board: Technologic Systems TS-7553-V2
I2C:   ready
DRAM:  512 MiB
MMC:   FSL_SDHC: 0, FSL_SDHC: 1
Net:   FEC0 [PRIME]
Booting from the SD card ...
** File not found /boot/boot.ub **
34511 bytes read in 162 ms (208 KiB/s)
5460520 bytes read in 391 ms (13.3 MiB/s)
NO CHRG jumper is set, not waiting
Kernel image @ 0x80800000 [ 0x000000 - 0x535228 ]
## Flattened Device Tree blob at 83000000
   Booting using the fdt blob at 0x83000000
   Using Device Tree in place at 83000000, end 8300b6ce

Starting kernel ...

By default the board will boot to SD or eMMC depending on the status of the "SD Boot" jumper on startup.

Entering U-Boot shell

The U-Boot shell is a powerful tool. It allows modification of the environment, as well as the ability to run commands directly. By default, there are two ways to enter the shell: Set the U-Boot jumper, or press and hold the Push Switch before applying power and hold it for 5 seconds. When entering the U-Boot shell, it will attempt to run a script on a USB mass storage device before finally dropping to the shell.

The reset switch is provided as a convenience, so U-Boot can be entered without having to open any kind of enclosure. It can also be disabled for security purposes. Even if the switch is disabled, the U-Boot shell can still be accessed by using the U-Boot jumper.

To disable the press-and-hold method of entering the U-Boot shell, use the following U-Boot commands: 

env set rstuboot 0
env save

By setting the env var, rstuboot, to a 1, the push-and-hold method can be re-enabled.

U-Boot Environment

The eMMC flash contains both the U-Boot executable binary and U-Boot environment. Our default build has 2 MiB of environment space which can be used for variables and boot scripts. The following commands are examples of how to manipulate the U-Boot environment: 

# Print all environment variables
env print -a

# Sets the variable bootdelay to 5 seconds
env set bootdelay 5;

# Variables can also contain commands
env set hellocmd 'led red on; echo Hello world; led green on;'

# Execute commands saved in a variable
env run hellocmd;

# Commit environment changes to the SPI flash
# Otherwise changes are lost
env save

# Restore environment to default
env default -a

# Remove a variable
env delete emmcboot

U-Boot Commands

# The most important command is 
help
# This can also be used to see more information on a specific command
help i2c

# This is a command added to U-Boot by TS to read the baseboard ID on our 
# System on Module devices
bbdetect
echo ${baseboard} ${baseboardid} 
# The echo will return something similar to:
# TS-8390 2

# Boots into the binary at $loadaddr.  The loaded file needs to have
# the U-Boot header from mkimage.  A uImage already contains this.
bootm
# Boots into the binary at $loadaddr, skips the initrd, specifies
# the FDT addrress so Linux knows where to find the device tree
bootm ${loadaddr} - ${fdtaddr}

# Boot a Linux zImage loaded at $loadaddr
bootz
# Boot in to a Linux zImage at $loadaddr, skip initrd, specifies
# the FDT address to Linux knows where to find the device tree
bootz ${loadaddr} - ${fdtaddr}

# Get a DHCP address
dhcp
# This sets ${ipaddr}, ${dnsip}, ${gatewayip}, ${netmask}
# and ${ip_dyn} which can be used to check if the dhcp was successful

# These commands are used for scripting:
false # do nothing, unsuccessfully
true # do nothing, successfully

# This command can set fuses in the processor
# Setting fuses can brick the unit, will void the warranty,
# and should not be done in most cases
fuse

# GPIO can be manipulated from U-Boot.  Keep in mind that the IOMUX 
# in U-Boot is only setup enough to boot the device, so not all pins will
# be set to GPIO mode out of the box.  Boot to the full operating system
# for more GPIO support.
# GPIO are specified in bank and IO in this manual.  U-Boot uses a flat numberspace,
# so for bank 2 DIO 25, this would be number (32*1)+25=89
# The formula thus being (32*(bank-1)+dio)=flattened_dio
# Note that on some products, bank 1 is the first bank
# Set 2_25 low
gpio clear 83
# Set 2_25 high
gpio set 83
# Read 2_25
gpio input 83

# Control LEDs
led red on
led green on
led all off
led red toggle

# This command is used to copy a file from most devices
# Load kernel from SD
load mmc 0:1 ${loadaddr} /boot/uImage
# Load Kernel from eMMC
load mmc 1:1 ${loadaddr} /boot/uImage
# Load kernel from USB
usb start
load usb 0:1 ${loadaddr} /boot/uImage
# Load kernel from SATA
sata init
load sata 0:1 ${loadaddr} /boot/uImage

# View the FDT from U-Boot
load mmc 0:1 ${fdtaddr} /boot/imx6q-ts4900.dtb
fdt addr ${fdtaddr}
fdt print

# It is possible to blindly jump to any memory location
# This is similar to bootm, but it does not require
# the use of the U-Boot header
load mmc 0:1 ${loadaddr} /boot/custombinary
go ${loadaddr}

# Browse fat, ext2, ext3, or ext4 filesystems:
ls mmc 0:1 /

# Access memory like devmem in Linux, read/write arbitrary memory
# using mw and md
# write
mw 0x10000000 0xc0ffee00 1
# read
md 0x10000000 1

# Test memory.
mtest

# Check for new SD card
mmc rescan
# Read SD card size
mmc dev 0
mmcinfo
# Read eMMC Size
mmc dev 1
mmcinfo

# The NFS command is like 'load', but used over the network
dhcp
env set serverip 192.168.0.11
nfs ${loadaddr} 192.168.0.11:/path/to/somefile

# Test ICMP
dhcp
ping 192.168.0.11

# Reboot
reset

# SPI access is through the SF command
# Be careful with sf commands since
# this is where U-Boot and the FPGA bitstream exist
# Improper use can render the board unbootable
sf probe

# Delay in seconds
sleep 10

# Load HUSH scripts that have been created with mkimage
load mmc 0:1 ${loadaddr} /boot/ubootscript
source ${loadaddr}

# Most commands have return values that can be used to test
# success, and HUSH scripting supports comparisons like
# test in Bash, but much more minimal
if load mmc 1:1 ${fdtaddr} /boot/uImage;
	then echo Loaded Kernel
else
	echo Could not find kernel
fi

# Commands can be timed with "time"
time sf probe

# Print U-Boot version/build information
version

Modify Linux Kernel cmdline

The Linux kernel cmdline can be customized by modifying the cmdline_append variable. If new arguments are added, the existing value should also be included with the new arguments. 

env set cmdline_append rw rootwait console=ttymxc0,115200 quiet
env save

The kernel command line can also be modified from from the onboard Linux. From the linux shell prompt run the following commands to install the necessary tools and create the script: 

apt-get update && apt-get install u-boot-tools -y
echo "env set cmdline_append rw rootwait console=ttymxc0,115200 quiet" > /boot/boot.scr
mkimage -A arm -T script -C none -n 'tsimx6ul boot script' -d /boot/boot.scr /boot/boot.ub

The boot.scr includes the plain text commands to be run in U-Boot on startup. The mkimage tool adds a checksum and header to this file which can be loaded by U-Boot. The .ub file should not be edited directly.

Booting From NFS

U-Boot's NFS support can be used to load a kernel, device tree binary, and root filesystem. The default scripts include an example NFS boot script. Because of the way U-Boot tries to infer server data, the script we use will bypass this, making it more straightforward to use an NFS root that will not be heavily dependent on a particular network configuration. 

# Set this to your NFS server IP and NFS directory path
env set nfsroot 192.168.0.1:/path/to/nfs/rootfs/
env save

To boot your NFS root: 

# Boot to NFS once
run nfsboot;

# To make the NFS boot the persistent default
env set bootcmd run nfsboot;
env save
Note: If 'bootcmd' is used to test for whether the system should stop at the U-Boot shell or continue, the above will make it difficult to get back to the U-Boot shell as it will always attempt to boot regardless of jumper status.

Booting From USB

By default, U-Boot will attempt to read a U-Boot script from a USB drive when the U-Boot jumper is set (or the reset button is enabled and depressed). It copies /tsinit.ub into memory and jumps in to the script. To make a bootable drive, create a single ext4 partition on a USB drive and unpack the rootfs tarball located here

The one addition is to create the tsinit.ub file in the root of the USB drive. In order to do this, a U-Boot script must be created and then converted to the .ub format. This process requires a set of U-Boot specific tools. These are available on most every linux distribution, the instructions below are for Debian, either run on a host PC or on the device itself. See the package installation documentation for other respective distributions.

Install U-Boot tools in Debian 

apt-get update && apt-get install u-boot-tools -y

Create the file tsinit.scr in the root of the USB drive with the linux filesystem: 

# Prepare with:
# mkimage -A arm -T script -C none -n 'ts7553v2 usb' -d tsinit.scr tsinit.ub

# DO NOT MANUALLY EDIT THE .UB FILE

load usb 0:1 ${fdtaddr} /boot/imx6ul-ts7553v2${variant}.dtb;

load usb 0:1 ${loadaddr} /boot/zImage;

setenv bootargs root=/dev/sda1 ${cmdline_append};
bootz ${loadaddr} - ${fdtaddr};

Then in the same directory generate the tsinit.ub file: 

mkimage -A arm -T script -C none -n 'ts7553v2 usb' -d tsinit.scr tsinit.ub

Update U-Boot

WARNING: Installing a custom U-Boot is not recommended and may cause the device to fail to boot.

The latest U-Boot binary can be downloaded from the TS-7553-V2 FTP site. Copy this file to /boot/u-boot.imx on the 1st partition of the SD card. The U-Boot binary can be updated by inserting that SD card in to the TS-7553-V2, setting the U-Boot and SD card jumpers, and powering up the unit. At the U-Boot prompt, the following command can be used: 

run update-uboot

The above script will use the /boot/u-boot.imx file from the SD card or eMMC, depending on the state of the SD Boot jumper.

U-Boot Development

We do provide our U-Boot sources, but we do not recommend rebuilding a custom U-Boot binary as it can leave the system in an unbootable state.

If you still want to proceed with building a custom U-Boot, use the "tsimx_v2016.03_4.1.15_2.0.0_ga" branch from the github here: https://github.com/embeddedTS/u-boot-imx

When compiling, we recommend using ONLY this cross-compiler, the use of any other compiler may cause issues. Specifically, we have experienced RAM problems when using a more recent cross compiler to build this version of U-Boot. The use of any other compiler may leave the system in an unbootable state! 

export ARCH=arm
export CROSS_COMPILE=/path/to/folder/bin/arm-tsimx6ul-linux-gnueabihf-

make ts7553v2_defconfig
make u-boot.imx

This will output a u-boot.imx that can be written to the device using the steps in Update U-Boot.

POST

The TS-7553-V2 includes a simple POST test. This is normally used in production to verify basic functionality rapidly before doing more thorough testing. By default, this is not enabled on every boot, but it can be added via U-Boot scripting if there is a need for additional confidence in the application. The POST test quickly verifies basic functionality of: USB, RTC, Ethernet PHY, FRAM (if present), WiFi/BT module (if present), eMMC (see warning below), RAM, and the supervisory microcontroller.

The post test can be run with the following command in U-Boot: 

post
WARNING: The 'post' command has an optional "-d" argument; when this argument is passed it does a write and readback test of the eMMC and FRAM which is DESTRUCTIVE to the data on the disk! Note that it will not modify the boot sector contents of the eMMC. The eMMC chip is still tested for basic functionality without the argument passed, but no data is read or written from the disk itself.

Debian Configuration

For development, it is recommended to work directly in Debian on the SD card. Debian provides many more packages and a much more familiar environment for users already versed in Debian. Through Debian it is possible to configure the network, use the 'apt-get' suite to manage packages, and perform other configuration tasks. Out of the box the Debian distribution does not have any default username/password set. The account "root" is set up with no password configured. It is possible to log in via the serial console without a password but many services such as ssh will require a password set or will not allow root login at all. It is advised to set a root password and create a user account when the unit is first booted.

Note: Setting up a password for root is only feasible on the uSD image.

It is also possible to cross compile applications. Using a Debian host system will allow for installing a cross compiler to build applications. The advantage of using a Debian host system comes from compiling against libraries. Debian cross platform support allows one to install the necessary development libraries on the host, building the application on the host, and simply installing the runtime libraries on the target device. The library versions will be the same and completely compatible with each other. See the respective Debian cross compiling section for more information.

Configuring the Network

From almost any Linux system you can use 'ip' command or the 'ifconfig' and 'route' commands to initially set up the network. 

# Bring up the CPU network interface
ifconfig eth0 up

# Or if you're on a baseboard with a second ethernet port, you can use that as:
ifconfig eth1 up

# Set an ip address (assumes 255.255.255.0 subnet mask)
ifconfig eth0 192.168.0.50

# Set a specific subnet
ifconfig eth0 192.168.0.50 netmask 255.255.0.0

# Configure your route.  This is the server that provides your internet connection.
route add default gw 192.168.0.1

# Edit /etc/resolv.conf for your DNS server
echo "nameserver 192.168.0.1" > /etc/resolv.conf

Most networks will offer a DHCP server, an IP address can be obtained from a server with a single command in linux:

Configure DHCP in Debian: 

# To setup the default CPU ethernet port
dhclient eth0
# Or if you're on a baseboard with a second ethernet port, you can use that as:
dhclient eth1
# You can configure all ethernet ports for a dhcp response with
dhclient


Systemd provides a networking configuration option to allow for automatic configuration on startup. Systemd-networkd has a number of different configuration files, some of the default examples and setup steps are outlined below.

/etc/systemd/network/eth.network 

[Match]
Name=eth*

[Network]
DHCP=yes

To use DHCP to configure DNS via systemd, start and enable the network name resolver service, systemd-resolved: 

systemctl start systemd-resolved.service 
systemctl enable systemd-resolved.service
ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf


For a static config create a network configuration for that specific interface.

/etc/systemd/network/eth0.network 

[Match]
Name=eth0

[Network]
Address=192.168.0.50/24
Gateway=192.168.0.1
DNS=192.168.0.1

For more information on networking, see Debian and systemd's documentation:

WIFI Client

If connecting to a WPA/WPA2 network, a wpa_supplicant config file must first be created: 

wpa_passphrase yournetwork yournetworkpassphrase > /etc/wpa_supplicant/wpa_supplicant-wlan0.conf


Create the file /lib/systemd/system/wpa_supplicant@.service with these contents 

[Unit]
Description=WPA supplicant daemon (interface-specific version)
Requires=sys-subsystem-net-devices-%i.device
After=sys-subsystem-net-devices-%i.device

[Service]
Type=simple
ExecStart=/sbin/wpa_supplicant -c/etc/wpa_supplicant/wpa_supplicant-%I.conf -i%I

[Install]
Alias=multi-user.target.wants/wpa_supplicant@%i.service


Create the file /etc/systemd/network/wlan0.network with: 

[Match]
Name=wlan0

[Network]
DHCP=yes

See the systemctl-networkd example for setting a static IP for a network interface. The wlan0.network can be configured the same way as an eth.network.


To enable all of the changes that have been made, run the following commands: 

systemctl enable wpa_supplicant@wlan0
systemctl start wpa_supplicant@wlan0
systemctl restart systemd-networkd

Host a WIFI Access Point

First, hostapd needs to be installed in order to manage the access point on the device: 

apt-get update && apt-get install hostapd -y


Note: The install process will start an unconfigured hostapd process. This process must be killed and restarted before a new hostapd.conf will take effect.

Edit /etc/hostapd/hostapd.conf to include the following lines: 

interface=wlan0
driver=nl80211
ssid=YourAPName
channel=1
Note: Refer to the kernel's hostapd documentation for more wireless configuration options.


To start the access point launch hostapd: 

hostapd /etc/hostapd/hostapd.conf &

This will start up an access point that can be detected by WIFI clients. A DHCP server will likely be desired to assign IP addresses. Refer to Debian's documentation for more details on DHCP configuration.

Cellular Data Network

Note: This section is incomplete at this time.

The TS-7553-V2 includes support for the Multitech MTSMC-G2 or MTSMC-H5 which can connect to the internet using pppd. The modem is attached to the HD1 Header, also called the Daughter Card interface. The modem itself can be configuring with the following command: 

ln -s /dev/ttyAPP3 /dev/ttymultidc


Additionally, the DIO pin that connects to the RTS pin of the modem needs to be set to an output and driven low in order to allow communication with the modem: 

echo "40" > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio40/direction
echo "0" > /sys/class/gpio/gpio40/value


The pppd application must be installed and any required modules loaded: 

apt-get update && apt-get install -y ppp

This example is configured for T-Mobile in the US:

/etc/ppp/peers/tmobile 


/dev/ttymultidc
noauth
115200
debug
usepeerdns
persist
defaultroute

connect "/usr/sbin/chat -v -f /etc/ppp/chatscripts/tmobile"
disconnect "/usr/sbin/chat -v -f /etc/ppp/chatscripts/tmobile-disconnect"

/etc/ppp/chatscripts/tmobile 

TIMEOUT 10
ABORT 'BUSY'
ABORT 'NO ANSWER'
ABORT 'ERROR'

"" "\p\p\p\p\p\p\p\p\p\p\p\p+++\p\p\p\p\p\p\p\p\p\p\p\p"
"" "ATH0"

"OK" 'AT+CGDCONT=1,"IP","wap.voicestream.com"'

ABORT 'NO CARRIER'
OK 'ATD*99***1#'
CONNECT

/etc/ppp/chatscripts/tmobile-disconnect 

"" "\K"
"" "+++ATH0"

Using a different carrier you will likely only need to replace wap.voicestream.com with the access point for your carrier.

To start pppd: 

pppd call tmobile

# Or for more logging information:
# pppd nodetach call tmobile

This will create a ppp0 interface that can now be used as a standard network interface, and should set up a default route to the internet. For other carriers, typically you will only need a different access point listed in the AT+CGDCONT call, but further adjustments may be necessary.


Note: We have observed that the MTSMC-H5 connected to some networks has issues at or below 115200 baud. The issues observed are connection timeouts with the network itself. The connection between the modem and host device remain rock solid. While many applications are tolerant to the connection being reset, we have found some network downloads will abort without being able to recover. Running the unit at a faster baud rate, 230400 or higher, has been observed to eliminate this issue entirely. This does mean, however, that every time the device is started up, the modem must be issued an AT+IPR command (as noted below) at 115200 baud, then pppd started with the matched and higher baud rate in the peer script as shown above.


Faster Data Rates

While the MTSMC-G2 (GPRS) is limited to 115200 baud, the MTSMC-H5 (HDSPA) can communicate over serial up to 921600 allowing actual transfer rates around 80-90KB/s.

To set a custom baudrate in Linux, the method depends on the CPU and kernel support. More recent UART peripherals have a higher clock and a smarter driver, and can therefore use custom baud rates inherently. However, some systems require the use of 'setserial' using the spd_cust flag and some manual settings. When the spd_cust baud rate is set, Linux will re-purpose 38400 baud to use the set custom baud rate.


First, test the unit to see if it is possible to open up the UART with a higher baud rate: 

picocom -b 921600 /dev/ttymultidc

If the higher baud is unsupported, picocom will return a failure similar to the following: 

FATAL: failed to add device /dev/ttymultidc: Invalid baud rate

If the above error is received, then the method below using setserial must be used.

Otherwise, the port can be closed, re-opened at 115200 baud to communicate with the modem, and then the following command can be used to tell the cell modem to enter a higher baud rate: 

AT+IPR=921600

Now the port can be closed everything will function at the higher baud rate. Be sure to update the providers file. Using the example T-Mobile configuration, edit /etc/ppp/peers/tmobile and change 115200 to 38400. Starting pppd will now allow communication around 80-90KB/s (depending on your local cell tower's availability).


Common Baud Rates
Divisor Rate
1 921600
2 460800
3 307200
4 230400
5 184320
6 153600
7 131657
8 115200

Larger divisors will also work, but this should cover the common range. Using the setserial command you can specify the divisor. For example, to reach 115200 with the alternative baud base: 

setserial /dev/ttymultidc spd_cust baud_base 921600 divisor 8

Next you will need to tell the modem to communicate at the faster baud rates. You can use a client like picocom or minicom to connect directly to the modem to send it commands. 

picocom -b 38400 /dev/ttymultidc

Even though we are talking at 115200, 38400 must be specified since we are using a custom baud_base. You can test communication with the modem again by typing "AT", pressing enter, and receiving "OK". To reconfigure the modem to the faster 921600 baud rate you can send it this command: 

AT+IPR=921600

This will respond with OK, but now you will need to quit out of picocom (ctrl a,x) and reconfigure the baud base to use divisor 1: 

setserial /dev/ttymultidc spd_cust baud_base 921600 divisor 1

The only change now needed is in your providers file. Using the example T-Mobile configuration , edit /etc/ppp/peers/tmobile and change 115200 to 38400. Starting pppd will now allow communication around 80-90KB/s (depending on your local cell tower's availability).


Troubleshooting

If you are not able to obtain a ppp connection there are a few values you can check:

Troubleshooting: Cell Signal

Make sure ppp is not running, and execute these commands to check the signal strength. 

stty raw -echo speed 115200 -F /dev/ttymultidc 
cat /dev/ttymultidc &
echo -e "AT+CSQ\r\n" > /dev/ttymultidc 
killall cat

The return value should be something like "+CSQ: 9,2", or with no connection, +CSQ: 99,99. The second argument is the signal strengh which follows this table:

RSSI return values
0 -113 dBm or less
1 -111 dBm
2 to 30 -109 to -53dBm
31 -51dBm or greater
99 not known or detectable

If you return 99, make sure the antenna is connected and that you are in an area with good signal from your provider. Even without a valid SIM card you can have a good connection. If you are in another country, you may need to adjust the band for those supported by your carrier. The default value is appropriate for most US based carriers. Refer to the +WMBS command in your AT command guide for more options.


Troubleshooting: SIM card

If you have a good signal strength but are not obtaining a connection you can verify that the modem is able to read the subscriber number. This proves your SIM card is valid. 

stty raw -echo speed 115200 -F /dev/ttymultidc 
cat /dev/ttymultidc &
echo -e "AT+CNUM\r\n" > /dev/ttymultidc 
killall cat

With a valid SIM this will return something like: 

+CNUM: "","12345678901",129

If the SIM not detected you will only read ERROR. Make sure in this case that the card is inserted in the right direction so the pads on the card line up with the socket.

Troubleshooting: Other Options

If neither of the above steps get you connected you may want to contact your service provider for more information about where your connection attempts are failing.

Installing New Software

Debian provides the apt-get system which allows management of pre-built applications. The apt tools require a network connection to the internet in order to automatically download and install new software. The update command will download a list of the current versions of pre-built packages.

Older Debian releases are moved to a different server to indicate it is no longer getting security updates. To download packages for these older distributions, edit /etc/apt/sources.list to only have the following lines:

Jessie: 

deb http://archive.debian.org/debian/ jessie main
deb-src http://archive.debian.org/debian/ jessie main

Wheezy: 

deb http://archive.debian.org/debian/ wheezy main
deb-src http://archive.debian.org/debian/ wheezy main

After modifying that file, be sure to update the package list: 

apt-get update

A common example is installing Java runtime support for a system. Find the package name first with search, and then install it. 

root@ts:~# apt-cache search openjdk
jvm-7-avian-jre - lightweight virtual machine using the OpenJDK class library
freemind - Java Program for creating and viewing Mindmaps
icedtea-7-plugin - web browser plugin based on OpenJDK and IcedTea to execute Java applets
default-jdk - Standard Java or Java compatible Development Kit
default-jdk-doc - Standard Java or Java compatible Development Kit (documentation)
default-jre - Standard Java or Java compatible Runtime
default-jre-headless - Standard Java or Java compatible Runtime (headless)
jtreg - Regression Test Harness for the OpenJDK platform
libreoffice - office productivity suite (metapackage)
icedtea-7-jre-jamvm - Alternative JVM for OpenJDK, using JamVM
openjdk-7-dbg - Java runtime based on OpenJDK (debugging symbols)
openjdk-7-demo - Java runtime based on OpenJDK (demos and examples)
openjdk-7-doc - OpenJDK Development Kit (JDK) documentation
openjdk-7-jdk - OpenJDK Development Kit (JDK)
openjdk-7-jre - OpenJDK Java runtime, using Hotspot Zero
openjdk-7-jre-headless - OpenJDK Java runtime, using Hotspot Zero (headless)
openjdk-7-jre-lib - OpenJDK Java runtime (architecture independent libraries)
openjdk-7-source - OpenJDK Development Kit (JDK) source files
uwsgi-app-integration-plugins - plugins for integration of uWSGI and application
uwsgi-plugin-jvm-openjdk-7 - Java plugin for uWSGI (OpenJDK 7)
uwsgi-plugin-jwsgi-openjdk-7 - JWSGI plugin for uWSGI (OpenJDK 7)

In this case you will want the openjdk-7-jre package. Names of packages are on Debian's wiki or the packages site.

With the package name apt-get install can be used to install the prebuilt packages. 

apt-get install openjdk-7-jre
# More than one package can be installed at a time.
apt-get install openjdk-7-jre nano vim mplayer

For more information on using apt-get refer to Debian's documentation here.

Setting up SSH

To install ssh, install the package as normal with apt-get: 

apt-get install openssh-server


Make sure the device is configured on the network and set a password for the remote user. SSH will not allow remote connections without a password or a valid SSH key pair. 

passwd root
Note: The default OpenSSH server will not permit root to login via SSH as a security precaution. To allow root to log in via ssh anyway, edit the /etc/ssh/sshd_config file and add the line PermitRootLogin yes in the authentication section. This change will take effect after reboot or after sshd service restart.

After this setup it is now possible to connect from a remote PC supporting SSH. On Linux/OS X this is the "ssh" command, or from Windows using a client such as PuTTY.

Note: If a DNS server is not present on the target network, it is possible to save time at login by adding "UseDNS no" in /etc/ssh/sshd_config.

Starting Automatically

A systemd service can be created to start up headless applications. Create a file in /etc/systemd/system/yourapp.service 

[Unit]
Description=Run an application on startup

[Service]
Type=simple
ExecStart=/usr/local/bin/your_app_or_script

[Install]
WantedBy=multi-user.target

If networking is a dependency add "After=network.target" in the Unit section. Once you have this file in place add it to startup with: 

# Start the app on startup, but will not start it now
systemctl enable yourapp.service

# Start the app now, but doesn't change auto startup
systemctl start yourapp.service
Note: See the systemd documentation for in depth documentation on services.

To start an application on bootup with X11 instead change the x-session-manager. By default the system starts xfce: 

root@ts:~# ls -lah /usr/bin/x-session-manager 
lrwxrwxrwx 1 root root 35 May 26  2015 /usr/bin/x-session-manager -> /etc/alternatives/x-session-manager
root@ts:~# ls -lah /etc/alternatives/x-session-manager
lrwxrwxrwx 1 root root 19 May 26  2015 /etc/alternatives/x-session-manager -> /usr/bin/startxfce4

The x-session can be modified to only start specified processes. Create the file /usr/bin/mini-x-session with these contents: 

#!/bin/bash
matchbox-window-manager -use_titlebar no &

exec xfce4-terminal

You may need to "apt-get install matchbox-window-manager." first. This is a tiny window manager which also has a few flags that simplify embedded use. Now enable this session manager and restart slim to restart x11 and show it now. 

chmod a+x /usr/bin/mini-x-session
rm /etc/alternatives/x-session-manager
ln -s /usr/bin/mini-x-session /etc/alternatives/x-session-manager
service slim restart

If the x-session-manager process ever closes x11 will restart. The exec command allows a new process to take over the existing PID. In the above example xfce4-terminal takes over the PID of x-session-manager. If the terminal is closed with commands like exit the slim/x11 processes will restart.

Backup / Restore

Note: This section is incomplete at this time.

If you are using a Windows workstation there is no support for writing directly to block devices. However, as long as one of your booting methods still can boot a kernel and the initrd you can rewrite everything by using a usb drive. This is also a good way to blast many stock boards when moving your product into production. You can find more information about this method with an example script here.

Note: Note that the MBR installed by default on this board contains a 446 byte bootloader program that loads the initial power-on kernel and initrd from the first and second partitions. Replacing it with an MBR found on a PC would not work as a PC MBR contains an x86 code bootup program.

MicroSD Card

MicroSD8GB.png Click to download the latest tarball.

Most SD cards ship with a single partition, which is ideal. However the instructions below will destroy the partition table and use 'parted' to recreate it and make a single partition. Note that any other preferred tool can be used instead, however the partition table must be "MBR" format for U-Boot to properly parse it.

Using other OSs

At this time, we're unable to provide assistance with writing SD cards for our products from non-Linux based operating systems. We acknowledge however, that there are methods to write images and files from a variety of difference operating systems. If a native installation of Linux is unavailable, we recommend using a Virtual Machine. See the Getting Started section for links to common virtualization software and Linux installation.

Using a Linux workstation

An SD card can be written to allow it to be bootable. Download the above file and write this from a Linux workstation using the information below. A USB SD adapter can be used to access the card; or if the workstation supports direct connection of SD cards, that can be used instead. Once inserted in to the workstation, it is necessary to discover which /dev/ device corresponds with the inserted SD card before the image can be written.

Option 1: using 'lsblk'

Newer distributions include a utility called 'lsblk' which allows simple identification of the intended card.

Note: This command may need to be run as the root user: 
$ lsblk

NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sdY      8:0    0   400G  0 disk 
├─sdY1   8:1    0   398G  0 part /
├─sdY2   8:2    0     1K  0 part 
└─sdY5   8:5    0     2G  0 part [SWAP]
sr0     11:0    1  1024M  0 rom  
sdX      8:32   1   3.9G  0 disk 
├─sdX1   8:33   1   7.9M  0 part 
├─sdX2   8:34   1     2M  0 part 
├─sdX3   8:35   1     2M  0 part 
└─sdX4   8:36   1   3.8G  0 part

In this case the, SD card is 4GB, so sdX is the target device and already contains 4 partitions. Note that sdX is not a real device, it could be sda, sdb, mmcblk0, etc. Technologic Systems is not responsible for any damages cause by using the improper device node for imaging an SD card. The instructions below to write to the device will destroy the partition table and any existing data!

Option 2: Using 'dmesg'

After plugging in the device, the 'dmesg' command can be used to list recent kernel events. When inserting a USB adapter, the last few lines of 'dmesg' output will be similar to the following (note that this command may need to be run as the root user): 

$ dmesg
...
scsi 54:0:0:0: Direct-Access     Generic  Storage Device   0.00 PQ: 0 ANSI: 2
sd 54:0:0:0: Attached scsi generic sg2 type 0
sd 54:0:0:0: [sdX] 3862528 512-byte logical blocks: (3.97 GB/3.84 GiB)
...

In this case, sdX is shown as a 3.97GB card with a single partition. Note that sdX is not a real device, it could be sda, sdb, mmcblk0, etc. Technologic Systems is not responsible for any damages cause by using the improper device node for imaging an SD card. The instructions below to write to the device will destroy the partition table and any existing data!


The instructions below use the latest stock image, but it is also possible to use this process to update the TS-7553-V2 to the Linux 4.9 kernel with Debian Stretch image.

The following commands will reformat the first partition of the SD card, and unpack the latest filesystem on there. Replace the "/dev/sdX" on the first line with the correct whole disk device node! 

# Update this variable to match the specific device node as it appears on your PC!
export SD_DEV="/dev/sdX"

# Verify nothing else has this mounted
sudo umount "${SD_DEV}"1

# Remove, and re-set the partition table, ensuring there is a single partition. Additional partitions can be added, however U-Boot expects the 1st partition to have the root filesystem tarball.
sudo dd if=/dev/zero bs=512 count=1 of="${SD_DEV}"
sudo parted -s -a optimal "${SD_DEV}" mklabel msdos
sudo parted -s -a optimal "${SD_DEV}" mkpart primary ext3 0% 100%
sudo mkfs.ext3 -F "${SD_DEV}"1

# Mount, unpack filesystem tarball, and flush all cached data
sudo mkfs.ext3 "${SD_DEV}"1
sudo mkdir /mnt/sd
sudo mount "${SD_DEV}"1 /mnt/sd/
wget https://files.embeddedTS.com/ts-arm-sbc/ts-7553-V2-linux/distributions/ts7553-V2-latest.tar.bz2
sudo tar -xf ts7553-V2-latest.tar.bz2 -C /mnt/sd
sudo umount /mnt/sd
sync
Note: The ext4 filesystem can be used instead of ext3, but it may require additional options. U-Boot does not support the 64bit addressing added as the default behavior in recent revisions of mkfs.ext4. If using e2fsprogs 1.43 or newer, the options "-O ^64bit,^metadata_csum" must be used with ext4 for proper compatibility. Older versions of e2fsprogs do not need these options passed nor are they needed for ext3.

Once written, the files on disk can be verified to ensure they are the same as the source files in the archive. Reinsert the disk to flush the block cache completely, then run the following commands (Note that this expects to have the bash variable still set up from above): 

sudo mount "${SD_DEV}"1 /mnt/sd
cd /mnt/sd/
sudo md5sum --quiet -c md5sums.txt
cd -
sudo umount /mnt/sd
sync

The md5sum command will report what differences there are, if any, and return if it passed or failed.

eMMC

Note: This section is incomplete at this time.

These commands assume you are booted to the SD card: 

# Verify nothing else has this mounted
umount /dev/mmcblk2p2

mkfs.ext4 /dev/mmcblk2p2
mkdir /mnt/emmc
mount /dev/mmcblk2p2 /mnt/emmc
wget ftp://ftp.embeddedarm.com/ts-arm-sbc/ts-7553-V2-linux/distributions/ts7553-V2-latest.tar.bz2
tar -xf ts7553-V2-latest.tar.bz2 -C /mnt/emmc
umount /mnt/emmc
sync


Software Development

Most of our examples are going to be in C, but Debian will include support for many more programming languages. Including (but not limited to) C++, PERL, PHP, SH, Java, BASIC, TCL, and Python. Most of the functionality from our software examples can be done from using system calls to run our userspace utilities. For higher performance, you will need to either use C/C++ or find functionally equivalent ways to perform the same actions as our examples. Our userspace applications are all designed to go through a TCP interface. By looking at the source for these applications, you can learn our protocol for communicating with the hardware interfaces in any language.

The most common method of development is directly on the SBC. Since debian has space available on the SD card, we include the build-essentials package which comes with everything you need to do C/C++ development on the board.


Editors

Vim is a very common editor to use in Linux. While it isn't the most intuitive at a first glance, you can run 'vimtutor' to get a ~30 minute instruction on how to use this editor. Once you get past the initial learning curve it can make you very productive. You can find the vim documentation here.

Emacs is another very common editor. Similar to vim, it is difficult to learn but rewarding in productivity. You can find documentation on emacs here.

Nano while not as commonly used for development is the easiest. It doesn't have as many features to assist in code development, but is much simpler to begin using right away. If you've used 'edit' on Windows/DOS, this will be very familiar. You can find nano documentation here.

Compilers

We only recommend the gnu compiler collection. There are many other commercial compilers which can also be used, but will not be supported by us. You can install gcc on most boards in Debian by simply running 'apt-get update && apt-get install build-essential'. This will include everything needed for standard development in c/c++.

You can find the gcc documentation here. You can find a simple hello world tutorial for c++ with gcc here.

Build tools

When developing your application typing out the compiler commands with all of your arguments would take forever. The most common way to handle these build systems is using a make file. This lets you define your project sources, libraries, linking, and desired targets. You can read more about makefiles here.

If you are building an application intended to be more portable than on this one system, you can also look into the automake tools which are intended to help make that easier. You can find an introduction to the autotools here.

Cmake is another alternative which generates a makefile. This is generally simpler than using automake, but is not as mature as the automake tools. You can find a tutorial here.

Debuggers

Linux has a few tools which are very helpful for debugging code. The first of which is gdb (part of the gnu compiler collection). This lets you run your code with breakpoints, get backgraces, step forward or backward, and pick apart memory while your application executes. You can find documentation on gdb here.

Strace will allow you to watch how your application interacts with the running kernel which can be useful for diagnostics. You can find the manual page here.

Ltrace will do the same thing with any generic library. You can find the manual page here.

Cross Compiling

Debian Jessie previously provided cross compilers via the Emdebian project. However, Emdebian has been unmaintained for a number of years and is no longer able to provide a viable install package. In order to cross compile from a Debian Jessie workstation, a third party cross compiler is required.

A Debian Jessie install on a workstation has the ability to build for the same release on other architectures using Debian binary libraries. A PC, virtual machine, or chroot will need to be used for this. Install Debian Jessie for your workstation here.

From a Debian workstation (not the target), run the following commands to set up the cross compiler. Note that this expects a 64-bit Debian Jessie install on the workstation. 32-bit installations are not supported at this time. 

# Run "lsb_release -a" and verify Debian 8.X is returned.  These instructions are not
# expected to work on any other version or distribution.

cd ~
wget http://ftp.embeddedTS.com/ftp/ts-arm-sbc/ts-7553-V2-linux/cross-toolchains/gcc-linaro-4.9-2016.02-x86_64_arm-linux-gnueabihf.tar.xz
# The above toolchain is from Linaro. Other cross compilers can be used but have not been tested.
mkdir cross_compiler
tar xvf gcc-linaro-4.9-2016.02-x86_64_arm-linux-gnueabihf.tar.xz -C ~/cross_compiler
export PATH=$PATH:~/cross_compiler/gcc-linaro-4.9-2016.02-x86_64_arm-linux-gnueabihf/bin/
# The 'export' command needs to be run every time the user logs in. It is possible to add this command to the user's ".bashrc" file
# in their home directory to ensure it is automatically run every time the user is logged in.
su root
dpkg --add-architecture armhf
apt-get update
apt-get install build-essential

This will install a toolchain that can be used with the prefix "arm-linux-gnueabihf-". The standard GCC tools will start with that name, eg "arm-linux-gnueabihf-gcc".

The toolchain can now compile a simple hello world application. Create hello-world.c on the Debian workstation: 

#include <stdio.h>
int main(){
    printf("Hello World\n");
}

To compile this: 

arm-linux-gnueabihf-gcc hello-world.c -o hello-world
file hello-world

This will return that the binary created is for ARM. Copy this to the target platform to run it there.

Debian Jessie supports multiarch which can install packages designed for other architectures. On workstations this is how 32-bit and 64-bit support is provided. This can also be used to install armhf packages on an x86 based workstation.

This cross compile environment can link to a shared library from the Debian root. The package would be installed in Debian on the workstation to provide headers and ".so" files. This is included in most "-dev" packages. When run on the arm target it will also need a copy of the library installed, but it does not need the -dev package. Note that since the cross compiler used is 3rd party and not directly from Debian, some compile commands that include libraries will need additional arguments to tell the compiler and linker where on the workstation to find the necessary headers and libraries. Usually, the additional arguments will look like the following string, however adjustments may need to be made depending on the application. 

 -I/usr/include -L/usr/lib/arm-linux-gnueabihf -L/lib/arm-linux-gnueabihf -Wl,-rpath=/usr/lib/arm-linux-gnueabihf,-rpath=/lib/arm-linux-gnueabihf



apt-get install libcurl4-openssl-dev:armhf

# Download the simple.c example from curl:
wget https://raw.githubusercontent.com/bagder/curl/master/docs/examples/simple.c
# After installing the supporting library, curl will link as compiling on the unit.
arm-linux-gnueabihf-gcc -I/usr/include -L/usr/lib/arm-linux-gnueabihf -L/lib/arm-linux-gnueabihf -Wl,-rpath=/usr/lib/arm-linux-gnueabihf,-rpath=/lib/arm-linux-gnueabihf simple.c -o simple -lcurl

Copy the binary to the target platform and run on the target. This can be accomplished with network protocols like NFS, SCP, FTP, etc.

If any created binaries do not rely on hardware support like GPIO or CAN, they can be run using qemu. 

# using the hello world example from before:
./hello-world
# Returns Exec format error
apt-get install qemu-user-static
./hello-world

Compile the Kernel

For adding new support to the kernel, or recompiling with more specific options you will need to have a compatible Linux workstation available that can handle the cross compiling. Compiling the kernel on the device is not supported or recommended.

Prerequisites

A cross compiler is necessary, for recent Debian distributions, please follow the Debian Jessie cross compiling instructions to install a compatible cross compiler.

For other distributions, please refer to their documentation to find equivalent tools.

Additionally, some libraries and tools are required for the kernel build process: 

# Install dependencies for kernel build
# The following command is for Ubuntu / Debian workstations. If using a different
# distribution, please consult distribution docs for the proper commands to install
# new packages/tools/libraries/etc.
apt-get install libncurses5-dev bc lzop


Download sources and configure 

git clone https://github.com/embeddedTS/linux-tsimx
cd linux-tsimx
git checkout ts-imx_4.1.15_2.0.0_ga

# These next commands set up some necessary environment variables
export ARCH=arm
export CROSS_COMPILE=arm-linux-gnueabihf-
export LOADADDR=0x80800000

# This sets up the default configuration that we ship with
make tsimx6ul_defconfig

Once you have the configuration ready you can make your changes to the kernel. Commonly a reason for recompiling is to add support that was not built into the standard image's kernel. You can get a menu to browse available options by running: 

make menuconfig

You can use the "/" key to search for specific terms through the kernel.

Build the kernel

Once you have it configured you can begin building the kernel. This usually takes about 5-10 minutes. This group of commands will also output a uImage file used by U-Boot on the TS-7680. 

make && make zImage && make modules

We recommend running 'make' with the -jX argument, where X is the number of CPU cores+1 present on the build machine. This will greatly increase build speed.

Install the kernel/initramfs, headers, and modules

Next you need to install the kernel and modules to the SD card. Use the following to update the kernel, headers, and modules, this assumes the SD card connected to the workstation is assigned the device node /dev/sdc, please adjust the first command based on your specific setup: 

export DEV=/dev/sdc1
sudo mkdir /mnt/sd
sudo mount "$DEV" /mnt/sd
sudo cp arch/arm/boot/zImage  /mnt/sd/boot/
sudo cp arch/arm/boot/dts/imx6*ts*.dtb /mnt/sd/boot/
INSTALL_MOD_PATH="/mnt/sd" sudo -E make modules_install 
sudo -E make headers_install INSTALL_HDR_PATH="/mnt/sd/usr"
sudo umount /mnt/sd/
sync

Features

Battery Backed RTC

The TS-7553-V2 implements a M41T00S STMicro Battery Backed RTC using an external and replaceable coin cell battery. This RTC is connected to the CPU via I2C and is handled by the kernel and is presented as a standard RTC device in linux.

CAN

Note: The TS-7553-V2 Rev. B PCB does not have software control of the CAN_EN# pin for the transceivers and they are always enabled. This will be addressed in the next hardware revision.


The i.MX6ul CPU has two FlexCAN ports that use the linux SocketCAN implementation. The ports can be set up and used with the following commands: 

ip link set can0 up type can bitrate 1000000
ip link set can1 up type can bitrate 1000000


At this point the ports can be used with standard SocketCAN libraries. In debian we provide cansend and candump to test the ports or as a simple packet send/recv tool. In order to test the two ports together, tie CAN_H of both CAN ports together, and do the same for CAN_L. Then use the following commands: 

candump can0 &
cansend can1 7Df#03010c
#This command will return
  can0  7DF  [3] 03010c


The above example packet is designed to work with the Ozen Elektronik myOByDic 1610 ECU simulator to read the RPM speed. In this case, the ECU simulator would return data from candump with: 

 <0x7e8> [8] 04 41 0c 60 40 00 00 00 
 <0x7e9> [8] 04 41 0c 60 40 00 00 00

In the output above, columns 6 and 7 are the current RPM value. This shows a simple way to prove out the communication before moving to another language.

The following example sends the same packet and parses the same response in C: 

#include <stdio.h>
#include <pthread.h>
#include <net/if.h>
#include <string.h>
#include <unistd.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <assert.h>
#include <linux/can.h>
#include <linux/can/raw.h>

int main(void)
{
	int s;
	int nbytes;
	struct sockaddr_can addr;
	struct can_frame frame;
	struct ifreq ifr;
	struct iovec iov;
	struct msghdr msg;
	char ctrlmsg[CMSG_SPACE(sizeof(struct timeval)) + CMSG_SPACE(sizeof(__u32))];
	char *ifname = "can0";
 
	if((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0) {
		perror("Error while opening socket");
		return -1;
	}
 
	strcpy(ifr.ifr_name, ifname);
	ioctl(s, SIOCGIFINDEX, &ifr);
	addr.can_family  = AF_CAN;
	addr.can_ifindex = ifr.ifr_ifindex;
 
	if(bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
		perror("socket");
		return -2;
	}
 
 	/* For the ozen myOByDic 1610 this requests the RPM guage */
	frame.can_id  = 0x7df;
	frame.can_dlc = 3;
	frame.data[0] = 3;
	frame.data[1] = 1;
	frame.data[2] = 0x0c;
 
	nbytes = write(s, &frame, sizeof(struct can_frame));
	if(nbytes < 0) {
		perror("write");
		return -3;
	}

	iov.iov_base = &frame;
	msg.msg_name = &addr;
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;
	msg.msg_control = &ctrlmsg;
	iov.iov_len = sizeof(frame);
	msg.msg_namelen = sizeof(struct sockaddr_can);
	msg.msg_controllen = sizeof(ctrlmsg);  
	msg.msg_flags = 0;

	do {
		nbytes = recvmsg(s, &msg, 0);
		if (nbytes < 0) {
			perror("read");
			return -4;
		}

		if (nbytes < (int)sizeof(struct can_frame)) {
			fprintf(stderr, "read: incomplete CAN frame\n");
		}
	} while(nbytes == 0);

	if(frame.data[0] == 0x4)
		printf("RPM at %d of 255\n", frame.data[3]);
 
	return 0;
}

See the Kernel's CAN documentation here. Other languages have bindings to access CAN such as Python, Java using JNI.

In production use of CAN we also recommend setting a restart-ms for each active CAN port. 

ip link set can0 type can restart-ms 100

This allows the CAN bus to automatically recover in the event of a bus-off condition.

CPU

This device features the i.MX6ul 528MHz or 696MHz Cortex-A7 from NXP/Freescale. For more information about the processor and it's included peripherals, refer to the CPU manual.

DIO

Note: This section is incomplete at this time.

The TS-7553-V2 offers DIO, inputs, and low-side switches to accommodate nearly every application. The DIO exposed to various headers and terminals are controlled via the FPGA or CPU. All DIOs are controlled via the kernel sysfs interface. See the kernel's documentation here for more detail. The FPGA DIO pins all implement a crossbar switch and can be set to any combination of inputs and outputs. All DIO are 3.3 V tolerant unless otherwise noted. The low-side switches are able to sink 500 mA each with a maximum voltage input of 30 V (protected by a 30 V Zener diode). The low-side switches, when de-asserted, are high impedance inputs with a pullup resistor. A logical 0 input occurs from roughly 0 V to 1.5 V, while a logical 1 input occurs from roughly 1.6 V and higher on the low-side switches when in input mode.

To interact with DIO pins through the sysfs interface, it first must be exported to userspace, for example, DIO 237 is the BT_EN pin provided by the FPGA: 

echo "237" > /sys/class/gpio/export

If you receive a permission denied on a pin that means it is claimed by another kernel driver. If it succeeds you will have a /sys/class/gpio/gpio237/ directory. The relevant files in this directory are: 

 direction - "out" or "in"
 value - write "1" or "0", or read "1" or "0" if direction is in
 edge - write with "rising", "falling", or "none"

# Set GPIO 237 high
echo "out" > /sys/class/gpio/gpio237/direction
echo "1" > /sys/class/gpio/gpio237/value
# Set GPIO 237 low
echo "0" > /sys/class/gpio/gpio237/value

# Read the value of GPIO 237
echo "in" > /sys/class/gpio/gpio237/direction
cat /sys/class/gpio/gpio237/value

As an output, the value file can be written to 0 for low (GND), or 1 for high (3.3V). As an input the GPIO pins do not have internal pullups but rather internal keepers. An external pullup resistor is required to properly bias the GPIO inputs. It is also possible to use any processor GPIO as an interrupt by writing the edge value, and then using select() or poll() on the value file for changes.

eMMC Interface

The i.MX6ul SD card controller supports the MMC specification, the TS-7553-V2 includes a soldered down eMMC IC to provide on-board flash media.

Our default software image contains 2 partitions:

Device Contents
/dev/mmcblk1 eMMC block device
/dev/mmcblk1boot0 eMMC boot partition
/dev/mmcblk1boot1 eMMC boot partition
/dev/mmcblk1p1 Full Debian linux partition


This platform includes a Micron eMMC module with builds that have "4096F" in the part number. Our off the shelf builds are 4GiB, but up to 64GiB are available for larger builds. The eMMC flash appears to Linux as an SD card at /dev/mmcblk1. Our default programming of the eMMC is the same as the SD card image for standard partitions, but includes additional boot partitions that are used by U-Boot and are not affected by the eMMC partition table.

The eMMC module has a similar concern by default to SD cards in that they should not be powered down during a write/erase cycle. However, this eMMC module includes support for setting a fuse for a "Write Reliability" mode, and a "psuedo SLC (pSLC)" mode. With both of these enabled then any writes will be atomic to 512B. If a sector is being written during a power loss, a block is guaranteed to have either the old or new data. Even in cases where the wrong data is present on the next boot, fsck is able to deal with the older data being present in a 512B block. The downsides to setting these modes are that it will reduce the overall write speed and halve the available space on the eMMC to roughly 1.759GiB.

The mmc-utils package is used to enable these modes.

WARNING: If you are using a custom configurated device with an eMMC sized larger than 4GB, contact us before using these commands. The numbers below will change with different flash sizes. 
mmc write_reliability set -n 0 /dev/mmcblk2
mmc enh_area set -y 0 1847296 /dev/mmcblk2
WARNING: Setting either of those modes is permanent and using the wrong value it is possible to essentially brick eMMC which will not be covered by the warranty. Evaluation units with fuses set will not be accepted through returns.

After this is run, reboot the unit. On all future boots the eMMC will be detected at the smaller size.

Ethernet Port

The NXP/Freescale processor implements a 10/100 ethernet controller with support built into the Linux kernel. Standard Linux utilities such as ifconfig/ip can be used to control this interface. See the Configuring the Network section for more details. For the specifics of this interface see the CPU manual.

External Reset

Note: Use caution when using the push switch as a hardware reset mechanism. Filesystem corruption can occur if proper precautions are not taken and a hardware reset occurs.


This SBC has a multi-purpose tactile button at a right angle to the PCB. This button can be used as a mechanism to issue a hardware reset to the SBC or as a way to wake up the device from its sleep modes (see Sleep for more information). Additionally, it can be set up as a generic input for user applications.

To enable or disable the hardware reset functionality: 

tsmicroctl --resetswitchon  #Enable hardware reset
tsmicroctl --resetswitchoff #Disable hardware reset


To read the state of the input pin, see the DIO section for information on reading the Push Switch.

I2C

The i.MX6ul CPU has two I2C peripherals, one of which is exposed on a pin header, HD1.

This interface is accessible via the linux i2c-dev subsystem, it is available on the device node /dev/i2c-2. See the kernel i2c-dev documentation for more information on using the I2C peripheral.

Jumpers

The TS-7553-V2 has a set of jumpers located near the SuperCaps on the edge of the SBC. These jumpers control a number of aspects of the TS-7553-V2's behavior. The jumpers are labeled on the silkscreen rather than numbered:

Label Description
NO Charge When jumper is set, disable charging of the SuperCaps. Beneficial for early development and testing.
SD Boot When jumper is set, boot kernel and Debian from the SD card. Otherwise boot kernel and Debian from eMMC. This jumper influences U-Boot behavior.
U Boot When jumper is set, pause booting in U-Boot and drop to a U-Boot shell. Otherwise booth straight to Debian.
CAN When jumper is set, adds a 120 ohm termination resistor across CAN1 H and L pins. (Note: the CAN2 interface always has a 120 ohm termination)
485 When jumper is set, adds a 120 ohm termination resistor across RS-485 + and - pins.

LEDs

On all of our SBCs we include 2 indicator LEDs which are under software control. You can manipulate these using "tshwctl --greenledon --redledon" or "tshwctl --greenledoff --redledoff". The LEDs have 4 behaviors from default software.

Green Behavior Red behavior Meaning
Solid On Off System is booted and running
Solid On On for approximately 20s, then off The red LED will remain on from power on until Debian has finished booting. The first boot of the unit will have the LED on longer as part of this process is generating SSH keys for the unit.
On for 10s, off for 100ms, and repeating On for 10s, off for 100ms, and repeating The watchdog is continuously resetting the board. This happens when the system cannot find a valid boot device, or the watchdog is otherwise not being fed. This is normally fed by the kernel once a valid boot media has started. See the #Watchdog section for more details.
Off Off The SBC is not able to boot. Typically either the board is not being supplied with enough voltage, or the SBC has been otherwise damaged. If a stable voltage is being provided and the supply is capable of providing at least 1A to the SBC, an RMA is suggested.
Blinking about 5ms on, about 10ms off. Blinking about 5ms on, about 10ms off. The board is receiving too little power, or something is drawing too much current from the unit's power rails.

The red and green LEDs can be controlled from userspace after bootup using the linux LED subsystem. For example, to turn on the red LED: 

echo 1 > /sys/class/leds/red-led/brightness


A number of triggers are also available, including timers, disk activity, and heartbeat. See the kernel LED documentation for more information on triggers and general use of LED class devices

MicroSD Card Interface

Note: This section is incomplete at this time.

The i.MX6ul SD card controller is used for the SD card present on the board which supports the SD and SDHC specifications. This controller has been tested with Sandisk Extreme SD cards which allow read speeds up to 20.5MB/s, and write speeds up to 21.5MB/s.

Our default software image contains a single partition:

Device Contents
/dev/mmcblk0 SD Card block device
/dev/mmcblk0p1 Full Debian linux partition

Reboot Source

The supervisory microcontroller is capable of saving and displaying the reason for the most recent reboot. This can be used to detect various errors that may occur in the field, as well as simple accounting of events. The source can be queried with tsmicroctl: 

tsmicroctl -i

reboot_source=poweron


Possible sources and causes are:

Source Possible causes
poweron Power removed, Super Caps discharged, and then power applied
brownout Like "poweron," however the SuperCaps have not fully discharged
WDT WDT timeout; reboot command (which reboots via WDT)
resetswitch The reset switch has been enabled and has been asserted
sleep The system has woken up from a sleep command

Relay

The TS-7553-V2 has one SPDT relay rated for 5 A at 277 VAC or 30 VDC that can be toggled through a DIO pin. The PCH-105D2H relay closes in 10ms, and opens in 5ms. A very safe assumption would be that it will switch after 20ms. The common, NO (Normally Open), and NC (Normally Closed) connections are brought out on a pin header. See the DIO section of the manual for information on manipulating the relays.

Contact Location
COM P1_7
NO P1_8
NC P1_6

Sleep

Note: This section is incomplete at this time.
Note: As soon as the sleep command is issued the unit will go to sleep. If the proper precautions are not taken, filesystem corruption can result as the sleep mode removes all power from the CPU and other peripherals on the SBC


The addition of a microcontroller on board this SBC allows it to play a supervisory role over the CPU.

Low power sleep mode will remove power from all of the rails, turning off the CPU and every other peripheral save for the microcontroller. This mode offers extreme power savings, only requiring around 90 mW of power, with the ability to wake up after an arbitrary timeout (up to 1847297s, which is 21d 9h 8m 17s) with a 1s resolution. In order to enter this mode, issue the following command: 

tsmicroctl --sleep --timewkup <time in seconds> --resetswitchwkup

Waking up from a sleep will take roughly 4-5s from when the timer expires or when the reset button is pressed. This is normal bootup time for the CPU.

Note that both --timewkup and --resetswitchwkup are optional arguments, you can pass none, one, or both. If no arguments are passed then the SBC will remain in sleep mode forever, until power is removed completely and re-applied. This can be useful instead of halting in linux as sleeping would consume far less power than simply halting the CPU. Be aware however, that if the Super Caps are installed they will keep power to the on-board microcontroller for a very long time. If the Super Caps are used than an external wakeup via timer or reset switch is highly recommended.

SPI

Note: This section is incomplete at this time.

This SBC utilizes all of the i.MX28 CPU SPI ports for the SD cards, therefore there is no externally available SPI peripheral from the CPU. Because of this, bitbanging is strongly recommended for any attached peripherals that would utilize SPI.

Technologic Systems recommends using direct bitbanging of SPI pins from userspace to drive an SPI interface. See the DIO section for further information on manipulating DIO pins.

Another option is to implement spi-gpio in linux. This allows for a SPI physical interface on GPIO pins, but uses the kernel SPI software interface to read and write data on the SPI bus. See linux kernel documentation, spi-gpio, and spidev for more information on this.

SuperCaps

Note: This section is incomplete at this time.

The TS-7553-V2 has an option to add two 2.7 V 10 F supercapacitors. These two SuperCaps can provide up to 20 seconds of power hold time automatically if the external power input is removed. The Power Fail input signal (see the DIO Section) can be used to determine if the exterior power has been removed or fallen below a valid input level. Using this signal, a proper shutdown can be issued to ensure that all data is flushed from cache to disk, and all disks are unmounted properly.

The SuperCaps charge and discharge is managed transparently by the supervisory microcontroller. A jumper is provided to disable the charging and use of the SuperCaps. This mode is very useful for development to allow for proper power-off conditions without having to wait for the SuperCaps to discharge. The supervisory microcontroller will also not allow the TS-7553-V2 to boot if power input is invalid. If the system reboots safely due to a power failure, it will remain in a powered off state until external power is re-applied, or the SuperCaps discharge below the sustainable threshold.

By default, a script is started with systemd to monitor the Power Fail pin, and present all logged in users with a message saying that the power has failed and a graceful shutdown is taking place if the power input has failed. This script is located at /usr/local/bin/tssupercapmon

Additionally, U-Boot can delay booting until the SuperCaps are charged to a certain percentage, and optionally print the current percentage once per second. These are controlled with the environment variables "chrg_pct" and "chrg_verb" By setting chrg_pct to anything other than 0 (0 means do not wait, which is the default behavior), booting will be delayed until that percentage is reached. Setting chrg_verb to 1 will enable the verbose printing of the current percentage every second. Note that the SuperCaps may be at "0%" for a large period of time, this is due to the charge level being below a voltage that can sustain the TS-7553-V2. See the U-Boot section for information on setting environment variables.

A recommended value is 100%. This value was chosen because it can ensure the system is powered long enough to boot up and safely shut down (and provide an additional 8 s of power) if power is immediately cut once booting has started. Please note that this only applies to the default stock image, any further changes to the TS-7553-V2 hardware or software, such as connecting powered devices like USB or adding additional applications may cause the recommended value to not sustain the TS-7553-V2 until a safe shutdown is completed. The time it takes to reach 100% charge will vary depending on the current charge of the SuperCaps. On average, it will take about 20 seconds to charge the SuperCaps to 100%; this is assuming the SuperCaps have very recently fallen below the threshold voltage to sustain the TS-7553-V2.


Temperature Sensor

Note: Pending software example

UARTs

Note: These sections are incomplete at this time.

The TS-7553-V2 CPU offers 5 UARTs. The table below lists the CPU UARTs with their pin locations.

Num. Dev. Name Type TX / + Loc. RX / - Loc. RTS Loc. CTS Loc.
0 ttyAPP0 RS-232 HD2_3 HD2_2 HD2_7 HD2_8
1 ttyAPP1 RS-232 J1_3 J1_2 N/A N/A
2 ttyAPP2 RS-485 J1_1 / HD2_1 J1_6 / HD2_6 N/A N/A
3 ttyAPP3 TTL HD1_12 HD1_10[1] N/A N/A
4 ttyAPP4 TTL CN4_3 / P3_3 CN4_2 / P3_2 N/A N/A
  1. ↑ 5 V tolerant input

RS-485

The TS-7553-V2 offers one RS-485 port. The half-duplex transmit-enable is handled by the CPU PWM and a hardware circuit to enable TXEN based on this PWM value. The following command must be issued before RS-485 will operate at the specified frequency with TXEN. 

tshwctl --baud <baud>

USB

Note: This section is incomplete at this time.

The USB host port is a standard USB 2.0 at 480Mbps. The Linux kernel provides most of the USB support, and some devices may require a kernel recompile. For creating custom USB support, libusb may be the easiest route.

USB 5V Power can be disabled or re-enabled using DIO 69, marked EN_USB_5V on the schematic. See the syscon for more information on using this bit.

See the WIFI-N-USB manual for information on our WIFI support.

Watchdog

Note: This section is incomplete at this time.

This SBC implements a Watch Dog Timer in a microcontroller on the SBC. An external WDT allows for high assurance operation of the WDT, as it uses external hardware, kernel level software, and userspace level software. If any of the three fail then the WDT will timeout and reboot the whole system. A standard kernel WDT driver is in place. As soon as the kernel starts it will start the WDT and feed it on 30 second timeouts every 15 seconds. If a userspace application opens and uses the watchdog file, the kernel will stop auto-feeding and the user application is now responsible for feeding the WDT. The kernel driver supports the "Magic Close" feature of the WDT. This means that a 'V' character must be fed in to the watchdog file before the file is closed in order to disable the WDT. Additionally, if the kernel is compiled with CONFIG_WATCHDOG_NOWAYOUT then the WDT can never be stopped once it is started at boot.

See the Linux WDT API documentation for more information.

External Interfaces

Note: These sections are incomplete at this time.

HD1 Pin Header

Pin Name
HD1_1 VIN
HD1_2 POE_78
HD1_3 GND
HD1_4 POE_45
HD1_5 GND
HD1_6 POE_TX
HD1_7 SPI_CS# / DIO 47 [1]
HD1_8 POE_RX
HD1_9 I2C_DAT / DIO 69 [1]
HD1_10 UART7_RXD [2]
HD1_11 USB Host -
HD1_12 UART7_TXD
HD1_13 USB Host +
HD1_14 I2C_CLK / DIO 70 [1]
HD1_15 5 V
HD1_16 5 V
HD1_17 SPI_MISO / DIO 111 [1]
HD1_18 SPI_MOSI / DIO 110 [1]
HD1_19 3.3 V
HD1_20 SPI_CLK / DIO 109 [1]
Pin Layout
1 2
3 4
5 6
7 8
9 10
11 12
13 14
15 16
17 18
19 20
  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Pin defaults to peripheral mode, must have mux set to DIO for DIO use.
  2. ↑ 5V tolerant input

HD2 COM2 Header

10pin com header.png

Pin Name
HD2_1 NC [1]
HD2_2 UART4_RXD
HD2_3 UART4_TXD
HD2_4 CAN2_H
HD2_5 GND
HD2_6 NC [1]
HD2_7 UART5_TXD
HD2_8 UART5_RXD
HD2_9 CAN2_L
HD2_10 NC

HD4 Keypad Interface

Pin Name
HD4_1 3.3 V
HD4_2 DIO 117
HD4_3 DIO 118
HD4_4 DIO 119
HD4_5 DIO 120
HD4_6 GND

CN5 XBee Socket

XBeesingle.png

Pin Name
CN4_1 VCC [2]
CN4_2 UART8_RXD
CN4_3 UART8_TXD
CN4_4 GND
CN4_5 XBee reset# / DIO 84
CN4_6 5 V [3]
CN4_7 USB Host +
CN4_8 USB Host -
CN4_9 DIO 40
CN4_10 GND
CN4_11 GND
CN4_12 DIO 46
CN4_13 NC
CN4_14 3.3 V
CN4_15 GND
CN4_16 DIO 41
CN4_17 NC
CN4_18 NC
CN4_19 NC
CN4_20 GND
  1. ↑ 1.0 1.1 Will be connected in the future.
  2. ↑ This pin will provide 3.3 V or 4 V depending on if "XBee 3.3 V" or "MODEM 5 V" is enabled. See the DIO section for more information.
  3. ↑ Enabled with "MODEM 5 V". See the DIO section for more information.

P1 Pin Header

Pin Name
1 Power in VCC
2 Power in VSS
3 UART2 RS-485 +
4 UART2 RS-485 -
5 GND
6 Relay NC
7 Relay COM
8 Relay NO

CN9 DB-9 Header

DB9.svg

Pin Name
1 UART2 RS-485 +
2 UART6_RXD
3 UART6_TXD
4 CAN1_H
5 GND
6 UART2 RS-485 -
7 UART6_RTS
8 UART6_CTS
9 CAN1_L
10 GND

Revisions and Changes

Microcontroller Changelog

PCB Revisions

Revision Changes
B Initial release

Software Images

Product Notes

FCC Advisory

This equipment generates, uses, and can radiate radio frequency energy and if not installed and used properly (that is, in strict accordance with the manufacturer's instructions), may cause interference to radio and television reception. It has been type tested and found to comply with the limits for a Class A digital device in accordance with the specifications in Part 15 of FCC Rules, which are designed to provide reasonable protection against such interference when operated in a commercial environment. Operation of this equipment in a residential area is likely to cause interference, in which case the owner will be required to correct the interference at his own expense.

If this equipment does cause interference, which can be determined by turning the unit on and off, the user is encouraged to try the following measures to correct the interference:

Reorient the receiving antenna. Relocate the unit with respect to the receiver. Plug the unit into a different outlet so that the unit and receiver are on different branch circuits. Ensure that mounting screws and connector attachment screws are tightly secured. Ensure that good quality, shielded, and grounded cables are used for all data communications. If necessary, the user should consult the dealer or an experienced radio/television technician for additional suggestions. The following booklets prepared by the Federal Communications Commission (FCC) may also prove helpful:

How to Identify and Resolve Radio-TV Interference Problems (Stock No. 004-000-000345-4) Interface Handbook (Stock No. 004-000-004505-7) These booklets may be purchased from the Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402.

Limited Warranty

See our Terms and Conditions for more details.

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