[Gta04-owner] working headset (configuration)

H. Nikolaus Schaller hns at goldelico.com
Thu Aug 2 17:55:16 CEST 2018

> Am 02.08.2018 um 17:24 schrieb Andreas Kemnade <andreas at kemnade.info>:
> Hi,
> On Sun, 22 Jul 2018 13:27:06 +0200
> "H. Nikolaus Schaller" <hns at goldelico.com> wrote:
>>> Am 21.07.2018 um 19:55 schrieb Andreas Kemnade <andreas at kemnade.info>:
>>> Hi,
>>> I am just back of my holiday bike trip. I wanted to use my headset
>>> (which is in a bad condition) to phone, but I was unable to get any
>>> input from the micro (arecord | aplay echo test). So my am wondering if
>>> anyone has a working configuration? @Nikolaus: Are there still
>>> openmoko headsets collecting dust at goldelico? Are there other
>>> compatible headsets?  
>> I have to check. Maybe I have one or two. Finding compatible headsets
>> isn't that easy since 2.5mm 4 pin are no longer common and there have
>> been two different pin layouts. AFAIR, there was a Nokia and a Motorola
>> pin assignment and the GTA02 was Motorola compatible. There should be
>> information on the Openmoko wiki.
> Ok, here is a big thinking error. I thought Openmoko Phone (including
> equipment) - GTA02-Mainboard + GTA04-Board = fully working Letux 2804 phone
> (including equipment).

Yes. It works with original OpenMoko Headset. Or a 2/3 pin headset (but
then of course without microphone...).

> So I never compared pinouts of the headset, according to the equation
> above. But the pinout is different. Well, in the past I have used the
> headset mainly as an antenna or sound output. So I never noticed.
> Just stereo and the mixer seems to be a bit strange.

The outer two rings (towards tip) are the same but the inner ones
(connected on a 3 pin connector are either GND - A/V or A/V - GND.

The ts3a227e data sheet has a good description. Interestingly, what
we have is called "Standard" in Table 1...

I have a similar problem with my TV-Out cable. Since the old one was broken,
I ordered a cheap one through some Internet reseller - and it has the other
pin assignment. The result is that the TVout goes to the shield
(incl. L/R audio)... And polarity is inverted.

> Now I have a Nokia HS-47 waiting to be rewired.

So I finally repaired the broken AV cable...


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