SIP Client

  • Hey Tinkerers.
    Im trying to setup a SIP client on a "old" Onion Omega 1 (the first ones). Also i have a rotary dial also that i want to hook up. Now im looking for a way to achieve that. I have little to none electronic skills, neither programming :-).
    I guess the rotary needs to get read out by a edge detection.
    Bell ringing i guess can be done with a relais.
    But i have no idea how to get a SIP client installed. Did some one Try that already?

  • Number 1 challenge is to find a speech codec in VoIP that is suitable for MT7688's CPU (not a performance oriented)
    since there is no DSP block to offload the burden.


  • I looked at a USB audio card. woudl that be an option?

  • Most likely not, since most of them are used for feeding digital form of audio (Hi-Fi as a main feature) into/out of a PC, while PC does the heavy lifting. You need something to perform the voice compression for the codec suite used in VoIP/SIP.

    P.S. MT7688 already has I2S audio I/O, even a hardware PCM module, so USB I/O is not even needed.
    The key is something (not to present) has to do a real heavy duty job which is speech codec.

  • So better take a Raspi or an alternative?

  • There are people trying softphone on RPi with various degrees of success (hint: voice quality and echo cancelling.)
    RPi family IMHO isn't price competitive. (Don't get me started on the real price of Zero and Zero W...)

    My suggestion is to get a unlocked VoIP gizmo from fleabay for $10- $20 and call it a day.

  • hm, thats not what i expected, but yeah as it look its not possilbe. woudl have been cool to have a old phone with ringdial and have full SIP compatibility.

    Thanks for the help anyways

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