iPhone or iPod Touch interface?

therecordingart · Jul 28, 2009

X-Posted to DIYStompboxes

I just picked up an iPod Touch and have a few projects that I want to run past some more experienced folks.

1. Breakout cable for mic/headphones: http://benttronics.blogspot.com/2009/05/audio-breakout-cable-for-ipodiphone.html

I'd like to build this and plug my guitar into the mic input to use the Peterson iStrobosoft Tuner. Peterson makes an adapter cable, but don't know if it is just a 4 conductor 3.5mm to 1/4" adapter or if there are any other components crammed inline. I don't know if the 2.7v or .73ma of current is of any concern to a guitar pickup.

2. Apparently, the dock pinout supports stereo line in and stereo line out. It'd be neat to create a breakout box for mobile stereo recording. Here is the pinout data http://pinouts.ru/PortableDevices/ipod_pinout.shtml .

Any comments, concerns, or really awesome ideas?

PRR · Jul 28, 2009

> Apparently, the dock pinout supports stereo line in and stereo line out

Macally iVoicePro fits iPod dock-port and gives you stereo line in -OR- stereo line out (not both at once). Line in is reasonably low hiss for a cheap toy.

Brolik · Jul 28, 2009

Not to highjack a thread, but I've got an idea I've been tossing around with a few electrical/software engineer friends of mine. Anyone thought of using an iPhone/iPod touch for a externally triggered sampler? if you could get midi information in (possibly using polyphonic tones much like an old phone modem) and audio out quick enough, couldn't I plug it in to a cheap/light keyboard and bring my sample instruments library around with me? Make traveling to shows a lot lighter for me, I could bring one keyboard instead of four. Plus couldn't I use the app to lay out the structure of a whole song or set so I could easily switch to the next instrument with one button? Furthermore, one could begin to sell sample instruments in the app store for $9.99 apiece. Only problem is when the phone rings in the middle of my set

.

Whaddya think? Major pitfalls other than processor speed? My key to millions? I guess not anymore now that I've let the cat outta the bag.

monter · Jul 31, 2009

Anyone knows how to activate "LINE IN" in iPod Touch 2G doc connector (30 pin).

I use FIRE Recorder, and i try to record from line input, but recorder doesn't recognize audio source from dock plug which I made.

I should use any resistor between pin 21 and GND, or maybe it is not enough, ipod need some digital (from IC) signal with "accessory protocol"..?

http://www.audiofile-engineering.com/
http://pinouts.ru/PortableDevices/ipod_pinout.shtml

therecordingart · Aug 1, 2009

Connecting a 68k resistor between pins 21 and 30 gave me line out, but haven't tried line in yet. I read one rumor that Apple crippled line in with one of the software updates so only authorized devices can use the line in. I'm sure there is a simple work around, but we just need to figure out if a) that rumor is true and b) how do you do it?

therecordingart · Aug 11, 2009

monter said:
Anyone knows how to activate "LINE IN" in iPod Touch 2G doc connector (30 pin).

I use FIRE Recorder, and i try to record from line input, but recorder doesn't recognize audio source from dock plug which I made.

I should use any resistor between pin 21 and GND, or maybe it is not enough, ipod need some digital (from IC) signal with "accessory protocol"..?

http://www.audiofile-engineering.com/
http://pinouts.ru/PortableDevices/ipod_pinout.shtm

Have you made any progress on this? I'm hoping to take apart a dock with line in to see what it's got inside.