The modems in Host Mobility's products typically provide support for both mobile (cellular) networks and Global Positioning System (GPS) functionality. Although communication methods with the modems may vary across our product range, this page highlights the shared common features among all the integrated modems in our products.
- Radio /dev/ttyUSB0
- GPS /dev/ttyUSB1
- AT commands /dev/ttyUSB2
- 4G/LTE /dev/ttyUSB3
- Radio /dev/ttyACM0
- GPS /dev/ttyACM1
- AT commands /dev/ttyACM2
- 4G/LTE /dev/ttyACM3
Controlling the modem with AT commands⚓︎
Simple read and write⚓︎
Better way to read and write⚓︎
Use microcom to connect to the modem. (Exit microcom with
To get more informative error messages, you can type:⚓︎
Test mobile network⚓︎
List all current network operators:
After 20--30 seconds, you get something similar to:
Check status of PIN code protection⚓︎
Global Positioning System (GPS)⚓︎
The GPS time can be extracted from the
$GPRMC string outputted by the GPS.
This time is backed up to facilitate faster GPS fix times, avoiding the need to restart from scratch with each GPS engine restart.
Additionally, this backed-up time serves as a fallback for applications in case the system time cannot be synchronized from the Internet for any reason. Please note that our default BSPs currently do not utilize this feature.
See also Real Time Clock (RTC).