Porting the Cellular Interface Library to another Modem

FreeRTOS Labs now supports AT commands, TCP offloaded Cellular abstraction Layer. In order to add support for a new cellular modem, the developer can use the common component that has already implemented the 3GPP standard AT commands.

In order to port the common component:

1. Implement the cellular modem porting interface defined in cellular_common_portable.h (Documentation).
2. Implement the subset of Cellular library API that use vendor-specific (non-3GPP) AT commands. The APIs to be implemented are the ones not marked with an “o” in this table.
3. Implement Cellular library callback functions that handle vendor-specific (non-3GPP) Unsolicited Result Code (URC). The URC handlers to be implemented are the ones not marked with an “o” in this table.

The Cellular common APIs document provides detail information required in each steps. It is recommended that you start by cloning the implementation of one of the existing modems, then make modifications where your modem’s vendor-specific (non-3GPP) AT commands are different.

Current Example Implementations:

• Quectel BG96
• Sierra Wireless HL7802
• u-blox Sara-R4