I have a EM12-G connected to a Linux machine running Modem Manager. Everything is working fine. Data works and I can even start calls with
mmcli -m 0 --voice-create-call=###
but the audio doesn’t work. I have tried both on an x86 PC with Pipewire and an i.MX based mobile device with Pulse audio.
I suspect I need something like this in the device tree: arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi · pureos/latest · Librem5 / linux · GitLab
And then some sort of Pulse audio settings.
Are there any examples or documentation on how to correctly setup audio routing for voice calls?
Maybe @Bean.Wang-Q has an idea of how to setup voice calls?
As I think this modem is data only.
The datasheet indicates that it does (PCM) as does this forum post
You can just try the AT command, Please do not try the ModemManager.
We cannot provide too much help with the ModemManager.
ModemManager works fine for starting the call. The trouble is that there is no audio. I’m really just looking for an example setup where audio does work, so I can see what changes are required for audio to work
I have tried a range of QDAI values, nothing seems to help. I have two way audio working, it’s just so distorted. Some audio codec somewhere is incorrectly setup, but I can’t figure out where or where to start debugging.
Can you provide details on how the modem is tested for audio calls? That might shed some light on what’s going on
Just to clarify. Audio in and out works, it’s just distorted. So the modem and the connection/setup supports audio.
Audio works on the exact same setup with a BroadMobi BM818 modem as well. So it’s some sort of encoding/decoding issues