call audio

[Xerxes 8933A/A]

The call audio is too bad to understand.  Broken mechanical static.  It is bad
for both incoming and outgoing calls.  I've tried the sound settings for the phone 
but nothing makes a difference.  Any clues?

So.  The plot thickens.

There are two speakers in this phone, the one you heard youtube on is the rear speaker. The garbled one in calls is the ear speaker.

My phone has the same issue as yours, can place a call, but then the call audio on the pinephone is garbled, but the audio for the call is otherwise fine (the other phone recieves the call fine and the mic input is sent and its perfect)

So I have disassembled the phone and tested the earpiece speaker.    29Ohms which is fine. I then used it with some test leads to play headphone output and it was fine if not that loud but definitely audiable.  So thats a red herring to suspect the speaker itself.  Whatever is happening is either hardware related internally or software.


No one else has had this issue?

I have seen it quite a bit in a bunch of threads. Likely software as calls didn't used to work but do now (with poor audio).

It is helpful that you confirmed is not a software issue.

I think you meant not a hardware issue ;-)

Thanks for confirming though that others have seen this issue.

I figured out a little time after I could reroute the audio internally, and the call audio was just as bad on the rear speaker, and the ear speaker worked fine for system audio so it seems the hardware is OK in that respect.

I wasn't expecting for calls to work (ie connect) but audio not working so it threw me a curve ball.  Sounds like it's pretty close to working though, you can almost make out the words ;-) The driver is doing a lot right, so that's a good start. I'm very new with this PinePhone stuff, so it'll take me a while before I understand the exact state of development and where/how things are being implemented. Think I'll hit up the postmarketos development community and see if I can find this exact issue and if anyone is working on it.

Yeah meant hardware, my mistake.

Given you like to tinker, you might as well dig in.

My suspicion is that it has to do with VOIP protocols/compression as I have also seen reports of clearer audio on 2G. (My phone is a couple countries away right now or I would tinker also)

I would say it's a simple fix to create a script to drop to 2G for calls....but at least in the US many carriers are getting rid of 2G in the near future.

Swordfish, thanks for your suggestions.  Call audio is now working for me but I must have the switchblock switch 6 (earphone/uart) in the OFF position.  If it's in the ON position (UART enabled) the call audio is fine!   I've switched it back and forth a few times to test. The outcome is the same each time.  UART enabled (switch 6 off = call audio works), Earphone enabled (switch 6 on = call audio metallic percussive distorted inaudiable)

So all seems well with the software I've been able to make calls with 3g and 4g now!  YAY.

That does seem to indicate a hardware issue though!   Fortuately I don't really care for the headphone that much ;-)  It would be interesting to know if anyone else has found the same issue has the same solution!

https://wiki.pine64.org/index.php/PinePh...figuration

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Hmmm....?
  I wonder if they used more than one OS version for the factory installations ?
    I have not changed any of my switches, on any of my Pine phones.

Curious,  Have you tried any other Distro's ?
 Mobian both the stable (on my Brave Heart) and Nightly (on my other convergent phone)
    are working very well also.

Not tried any others yet.

First thing I did on receiving the phone was disable everything by switchblock.  Except modem, mic, and earphone.   I tried to disable the modem but I get no cell service so I gather that is part and parcel of the voice function.

So switch 6 Pulls up IN2 on analog switch BCT4717ETB

https://datasheet.lcsc.com/szlcsc/180921...266763.pdf

Perhaps it's an implementation detail of the OS... I may be jumping to conclusion thinking theres a fault with some hardware, as other peoples phones are not seemingly doing this. It seems a bit fishy in the hardware location of BCT4717ETB to me.  I think it might warrent further investigation...  A 3mm x 2mm package with 10 pins under it ;-(

I will flash another OS on this as soon as I get time.. and see if that can yeild another result.

Atleast we're getting somewhere!

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  I wonder if they used more than one OS version for the factory installations ?

The OS on this one is

# uname -a

Linux pine64-pinephone 5.7.0 #3-postmarketos-allwinner SMP Tue Sep 1 15:05:31 UTC 2020 a arch64 Linux

# cd /etc; cat os-release

PRETTY_NAME="postmarketOS 1.22.0"
VERSION_ID="1.22.0"
VERSION="1.22.0-ec23a657"
ID_LIKE="alpine"
PMOS_HASH="ec23a657b545987e1c69551a83ce3646d3b7452d"

Not sure if there's any other identifying information I can extract but for comparison purposes that might suffice?