Sip Client

[PiVSS]

I'm very interested by the project and I am impressed by all the work done.

I plan to use the ZeroPhone as a SIP Phone over wifi (and maybe later over cellular if a 3G/4G modem is added).
I'm thinking to use PJSip as SIP client (http://www.pjsip.org/) and I'm currently doing some tests with ZPUI to create a friendly interface to manage it.

On the ZeroPhone block diagram the speaker & microphone seams related with the 2G modem.
How can this be a problem to use them for the sip client?
Do you see any other obstacle?

[CRImier]

Hi! Lack of a Pi-connected microphone is a problem, indeed. There are 3 solutions:

• Using an I2S microphone addon. I've designed one - it has to be soldered to the ZeroPhone SPI expansion header (very simple soldering). The downside - you lose 4 GPIO pins from the side expansion header, which might be a problem, but is likely OK for most of people.
• Using a BT microphone - either through a Pi Zero W's BT, or a USB-BT dongle. I'm not sure the throughput and stability of the Pi Zero W's Bluetooth is good enough for our purposes, I'll have to check.
• Using a USB microphone. It just works, however, it's obviously going to be wired.

For now, you can do all the testing with a USB microphone - later on, you'll be able to rely on either an I2S microphone (most likely) or a BT headset.

As a sidenote - do check out the ZPUI's 'devel branch'; it's lightyears in front of 'master' (which is something I intend to fix soon). I also acknowledge that ZPUI lacks plenty of things (like notifications); let me know - I can prioritize things in areas where you're lacking ZPUI capabilities. You could say this is the other obstacle I see, but I'm willing to work with you on that =)

[CRImier]

The devel branch is now merged in the master branch, check out the docs =)