Join Date: Nov 2010
Location: Gilbert, AZ, USA
Autocom & MP3 phone integration--control & power
I'm doing this with an iPhone, but it applies to any phone/MP3 player with a standard 3.5mm jack that has four poles and is compatible with 3-pole headphones. It's working great, both people can listen/talk on the phone, hear the music, or anything else from the phone such as Pandora.
Two areas that need improvement...powering the phone, and controlling it without having to use the touchscreen.
On power, the problem is that you can't power the Autocom and the devices it connects to without an isolation device. They don't have one that works with an MP3 phone. They just sell a cable for it, which they say *will* (not may) cause damage if you power both. I'm tempted, but not brave/stupid enough to find out. I wonder if anyone has found a good solution before I set about making my own. I suppose a DC-DC converter could isolate the power side. On the audio side, the speakers should be easy to isolate with a 1:1 transformer, but I have no idea what I could do with the mic input.
Controlling the phone/music should be pretty easy, though again, before I build something I figure I'd ask if others have a good solution. I thought about building a small box to put on the bars with a pushbutton. If you short the mic-ground leads, you can control the phone. During a call it's used for answer/hang up. When playing music, you can do pause/play/next track. And a press and hold will give you voice command.