Can the Modem Library back end be directed to an external modem?

[rdauben]

My understanding is that the Modem Library is a dedicated interface to the internal modem in the nRF9160.

We also need a 2nd modem interface to an external device that also uses AT commands.  Is it possible to create a 2nd instance of the Modem Library and configure its back end to handle the AT command interface to an external device?

Thanks.

Ron

[Øyvind]

Hey Ron, 

the DevZone team and Nordic Semiconductor are currently in a summer vacation period, some delays in answers must be expected due to lower staffing during this period. We apologize for the inconvenience. 

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We also need a 2nd modem interface to an external device that also uses AT commands.

What kind of modem is this? An additional nRF9160? If so, I will need to forward the question to our modem team. 

Kind regards,
Øyvind

[rdauben]

Our application needs cellular, BLE, and Wifi connectivity.  If we were to use the nrf52840 for its built-in BLE, we would need an external cellular modem device.  Instead, we have chosen to use the nRF9160, with its internal modem, as our application host processor.  So that requires that we use an external BLE and WiFi device (for example, Espressif ESP32) with an AT interface.

[Øyvind]

The modem library itself is for internal use in the nRF9160 SiP itself. The library implements a communication interface between the Application and Modem cores on the nRF9160 through the RPC protocol, using the Inter Processor Communication (IPC) peripheral and a shared region of RAM.

In order to send AT commands to another device you will need to use an application to send the AT commands via e.g. UART. 

If the 2nd modem should be another nRF9160, this device could run the Serial LTE Modem.