I have played around with my huawei modem to learn how to use the voice feature. There are ttyUSB0, ttyUSB1 and ttyUSB2.
0 and 2 are serials ports for AT-commands. At ttyUSB2, asynchron messages like RING appear on a incoming call.
When i send "AT^DDSETEX=2" while on a call, the modem enables voice on ttyUSB1.
With "aplay -f S16_LE -c 1 -r 8 /dev/ttyUSB1" its possible to hear the voice, but when i try "arecord -f S16_LE -c 1 -r 8 > /dev/ttyUSB1", the modem restarts itself.
Does anyone have experience with this? Will the pyra modem also work like this?
EDIT: got it.
aplay -fS16_LE -c1 -r8000 -F20000 --period-size=320 -t raw -N /dev/ttyUSB1
arecord -fS16_LE -c1 -r8000 -F20000--period-size=320 -t raw -N /dev/ttyUSB1
There is a delay, but its good enought to test the pyra call functionality.