GW16130 Iridium Satellite Modem

GW16130 = GW16127 Mini-PCIe carrier + Iridium 9603 modem module

Iridium 9602/9603 SBD (short burst data) modem is capable of transmitting ASCII or Binary messages in packets of up to 340 bytes, and receiving packets of up to 270 bytes.

Modem Activation

Modems need to be activated via an approved Iridium carrier / provider.

During the activation, the modem is configured for the destination of the messages:

• Direct IP
• Email address
• Another modem

Some providers found on the internet, but not endorsed or approved by Gateworks:

• ​https://www.northernaxcess.com/sbd-short-burst-data-airtime-plans
• ​https://satellitephonestore.com/iridium-sdb
• ​https://www.satphonestore.com/airtime/iridium-sbd.html
• ​http://www.rock7mobile.com/products-rockblock-9603
• ​http://www.nalresearch.com/Airtime.html#Short%20Burst%20Data%20(Standard%20Plan)

Turning on Modem

An FTDI FT231XQ USB UART Chip is used to communicate with the Iridium Satcom modem via its UART.

The FTDI GPIO pins control the modem:

• CBUS0: SAT_ON (input to modem; 10k pull-down)
• CBUS1: SAT_FND (output from modem)
• CBUS2: SAT_SUPPLY_OUT (output from modem)
• CBUS3: not connected

Configure GPIO:

base=$(for i in $(ls -1d /sys/class/gpio/gpiochip*); do [ "ftdi-cbus" = "$(cat $i/label)" ] && cat $i/base; done)
[ "$base" ] || { echo "Error: could not find ftdi-cbus device"; }
echo $((base+0)) > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio$((base+0))/direction
echo 1 > /sys/class/gpio/gpio$((base+0))/value # enable modem
echo $((base+1)) > /sys/class/gpio/export
echo in > /sys/class/gpio/gpio$((base+1))/direction
echo $((base+2)) > /sys/class/gpio/export
echo in > /sys/class/gpio/gpio$((base+2))/direction

Modem AT Commands

The Iridium SBD modems communicate via AT commands over a UART (default 19200 baud)

AT Commands via picocom: (only works if there is one ftdi device being used)

DEVICE=/dev/$(basename $(ls -d /sys/bus/usb/drivers/ftdi_sio/*/ttyUSB*))
picocom $DEVICE -b 19200 --omap lfcr

AT Commands via shell: (only works if there is one ftdi device being used)

DEVICE=/dev/$(basename $(ls -d /sys/bus/usb/drivers/ftdi_sio/*/ttyUSB*))
stty -F $DEVICE 19200 ignbrk -brkint -icrnl -opost -onlcr -isig -icanon -iexten -echo -echoe -echok -echoctl -echoke
cat $DEVICE &
at() { echo -n -e "$1\r" > $DEVICE; }
at "AT+GMI" # Manufacturer Identification 'Iridium'
at "AT+GMM" # Model Identification 'IRIDIUM 9600 Family SBD Transceiver'
at "AT+GMR" # Revision details
at "AT+GSN" # serial number (IEMI)
at "AT+CSQ" # signal strength (0 to 5): '+CSQ:0'

Additional commands:

• Send message on Modem (to destination configured in modem admin where modem is registered)

  AT&K0
  AT+SBDWT=Hello World
  AT+SBDIX
  

Reference Links

• Iridium 9603 ​https://www.iridium.com/products/iridium-9603/
• Iridium 9603 AT Commands ​https://www.google.com/search?q=iridium+9603+at+commands
• Drifting Buoy Project using 9603 ​http://mdbuoyproject.wixsite.com/default