TS-8700 Cell Network
This board includes support for the Multitech MTSMC-G2 or MTSMC-H5 which can connect to the internet using pppd. The #XUARTs do not have device nodes by default, but can be initialized using xuartctl:
eval $(xuartctl --server --port 2 --speed 115200 --mode=8n1 2>&1); ln -s $ttyname /dev/ttymultidc
You also must install pppd, and load the required modules:
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.
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 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:
| 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 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.