TS-4100 LEDs
The LEDs available to the TS-4100 are dependent on the baseboard that is used. However, all of our compatible baseboards will at lease provide a green and a red LED that is used for status as well as can be controlled by end applications. Note that when used standalone, the TS-4100 does not provide controllable status LEDs.
The kernel provides access to control the LEDs using the sysfs interface:
# Set Red led on
echo 1 > /sys/class/leds/red-led/brightness
# Set Red led off
echo 0 > /sys/class/leds/red-led/brightness
# Set Green led on
echo 1 > /sys/class/leds/green-led/brightness
# Set Green led off
echo 0 > /sys/class/leds/green-led/brightness
The kernel provides various triggers that can be useful for debugging purposes. The trigger file for a given LED is in its named sub-directory, e.g.
echo "heartbeat" > /sys/class/leds/red-led/trigger
| Trigger value | LED toggles on |
|---|---|
| none | Default, no action, manually controlled by brightness file
|
| rc-feedback | IR Reciever trigger [1] |
| can0-tx | CAN0 transmit activity |
| can0-rx | CAN0 receive activity |
| can0-rxtx | CAN0 activity |
| can1-tx | CAN1 transmit activity |
| can1-rx | CAN1 receive activity |
| can1-rxtx | CAN1 activity |
| mmc0 | microSD activity |
| mmc1 | eMMC activity |
| timer | 2hz blink |
| oneshot | Blinks after delay. [2] |
| heartbeat | Similar to timer, but varies the period based on system load |
| backlight | Toggles on FB_BLANK |
| gpio | Toggle based on a specified gpio. [3] |
| cpu0 | Blink on CPU core 0 activity |
| default-on | Only turns on by default. Only useful for device tree. |
| transient | Specify on/off with time to turn off. [4] |
- ↑ There is no IR directly on the TS-4100, this would be from a USB peripheral.
- ↑ See the Kernel documentation for more details on "oneshot" operation.
- ↑ When this trigger is set, a "gpio" file appears in the same directory which can be used to specify what GPIO to follow when it blinks
- ↑ See the Kernel documentation for more details on "transient" operation.
Reading the contents of the trigger will list all compatible triggers as well as the current trigger set. The currently set trigger is indicated by surrounding brackets, e.g. none [timer] cpu ...
Status LED Behavior
The following applies to the stock TS-4100 bootup process, from U-Boot to fully booted. Note that when used standalone, the TS-4100 does not provide these status LEDs.
| Green | Red | Meaning |
|---|---|---|
| Solid On | Off | System is booted and running. |
| Off | Solid On | The TS-4100 is in U-Boot. If the LEDs remain in this state for longer than a few seconds, U-Boot may be unable to find a proper boot device, or booting of the kernel failed. The green LED will flash briefly at power-on. |
| Off | Off | The device is not able to boot. Typically, either too low of an input voltage is provided or the unit has been otherwise damaged. If a stable voltage is being provided as per the power input specifications and the input power is able to meet the device's power consumption requirements, an RMA may be needed to have the unit diagnosed by our repair team. |
TS-4100 LED
The TS-4100 SoM has a single LED on the module itself. This is directly controlled by the supervisory microcontroller and is used to indicate its status.
At power-on of the microcontroller, when USB serial is connected or 5 VDC input to the module is valid, the green LED on the TS-4100 will flash once.
When the TS-SILO supercapacitors are charging, the green LED on the TS-4100 will be solidly lit. As the capacitors near their full charge value then LED will turn off. As the microcontroller tops up the charge to keep them at or as close to 100% as possible, this LED will turn on and off while charging is enabled and input power remains valid.