Connect door bell via WLAN(SIP) to VoIP server

[christian]

Hello,

i just cleaned up my project a bit and uploaded it to github, but it is still work in progress:
https://github.com/chrta/sip_call

When the door bell rings, a VoIP call is initiated. It keeps ringing for a predefined duration or until someone picks up the phone.

Hardware
I used a simple ESP32 dev board, that is connected to two opto couplers to detect a door bell signal (12V AC in my case). The opto couplers pull down a GPIO pin on the ESP32.

Firmware
The current implementation is tested with AVM Fritzbox 7490 (DSL router with internal SIP server). All configuration options are available via "make menuconfig".
The SIP protocol is self written and implemented "quick and dirty" for the Fritzbox. But it should not be too complicated to get it running for other SIP servers.

Regards,
Christian

[WiFive]

Nice are you going to try to get g.711 audio and rtp working?

[christian]

Nice are you going to try to get g.711 audio and rtp working?

I have tried that in the beginning, but struggled with sdp and rtp. At the moment i do not plan to implement it myself.
A receiving rtp socket is already set up, but all received data is discarded. No data is sent and the rtp reports (?) are ignored.