Mobile phone connector as Audio Input

[rowen]

Hi All,
I'm sure this has been asked 1000 times already, but I tried searching and couldn't find anything.

Would it be possible to somehow rig up the connections for the mobile phone car kit as an input for an MP3 player? I'm sure someone has tried this already...

[wafi]

http://members.cox.net/05gto/html/bo...-to-guides.htm

[Cherryknocker]

I've tried, It is possible, you need to send 12V to the mute signal wire and feed you audio too, but the signal is week. Does not work when you use a hardwired GSM kit though.

by a small FM transmitter and save youyrself the agro.

[Tasmaniak]

The two blue speaker wires on the inputs are Mono and not stereo. Plus, they are designed for speaker outputs and line levels

[Tasmaniak]

Also...do NOT give the stereo mute wire a 12V (+) input....it actualy needs an earth.

[rowen]

Well, I did this over the weekend. It was actually supprisingly easy and works (well works good enough for what I wanted).

Basically, I built up a small sound activated relay to earth the mute when an audio signal is inputted. This is all installed in a nice little project box and hooked up with a 3.5 mm socket so the mp3 player can be plugged in and removed without headaches, the cord hangs out under the side of the dash at the moment but I am going to feed it back into the dash so the mp3 player can be hidden incase the car is broken into. The relay has been built with a 5 second cut off, so it won't turn off until it hasn't recieved a signal for, you guessed it, 5 seconds, this is sufficient to stop it tripping at the end of each song, but I want to stretch it out to 10 seconds when I get around to it.

As has been stated, it's only a mono input which is a bit of a pain in the arse and the input signal is relatively week. Because of the weak signal, the radio volume and mp3 volume need to be ramped right up to get a decent sound output from the speakers, but thankfully blauplunkt was nice enough a make the radio store individual bass, treble, fader and volume settings for the voice in, so changing these settings while the mp3 player is active doesn't affect the settings of the normal radio/cd settings. To get around the weak signal problem I will put a small headphone amp in there oneday.

FM transmitter's completely suck arse and I hate them with a passion, which is why i didn't want to use one. The sound activated relay I rigged up came in around the $20 mark and an hour or so to get working. I beleive the sound quality here is no better or worse than an FM transmitter, but I think you'd be struggling to get a capable fm transmitter for $20.

If any one wants more details in the relay, feel free to post here.

Holden, please include a bloody line in on the next commodore!