Batboard

I am working on a little home project and basically need to get a PTT and mic audio into a iDen handset. I found a pinout for the 2.5mm connector, but the Tip is listed as MIC + PTT, does anyone know what circuit would be used to make that happen and still pass mic audio? I could just buy a PTT earbud and tear into it, I suppose. Does anyone know if there is a good source for a connector for the bottom of the phone to do that better? I am working with a i560.

What it means is that it's not as complex as it needs to be

You have Mic and Audio under the same pin... which means that the setup would be a microphone element connected in series with a PTT switch, then the other end of the connection to the ground reference on the 2.5mm plug.

-Josh

I see what you mean, I tried to simulate that and still couldnt get ptt. I want to route external audio to the mic circuit so this will probably become inherently more complicated.

Quarterwave wrote:I see what you mean, I tried to simulate that and still couldnt get ptt. I want to route external audio to the mic circuit so this will probably become inherently more complicated.

Ahh, well there may be a specific mic element impedance that needs to be met or something, it may be a case where finding a cheap PTT headset would be beneficial.

Sorry that didn't work... did you try simply shorting the PTT/MIC to ground?

-Josh

Yep

http://www.nexnow.com/i850-speaker-mic.html


Check that out, I had one a while back, It will work on more then the 850.


Chris