Getting signal into iPod Touch via mini jack ?

[Riley Casey]

I have acquired several TRRS style mine to RCA patch cables which as it turns out are called AV camera cables.  I have identified the appropriate contacts for what should be signal input to the Ipod touch ( Ring 2 and sleeve counting from the tip with Ring 2 being the common for all inputs and outputs ).  Signal Scope shows a " no input display " on the screen.  I can measure signal at the mini plug prior to mating with the Ipod touch.  Is there anything in Signal Suite or the Touch that I need to enable software wise to make Signal Suite look to the mini jack for input ?

I have moved this to a new topic since it the answer may not be the same as the iphone.

[FaberAST]

You must be referring to SignalScope, rather than SignalSuite (which is an output-only app).

Sometimes, you may need to plug/unplug the mini-plug a few times to get the iPod to recognize it.

It's important to keep in mind that this requires the 2nd generation iPod touch, since the original iPod touch does not support input through its headphones jack (it's not a headset jack).

Ben

[Riley Casey]

I am indeed attempting to get signal into a second generation iPod touch into Signal Scope.  Signal Scope will not accept audio from the mic input ring on the mini jack.  I have also installed an app called Recorder that will recognize a mic input.  What can I do to encourage Signal Scope to play nice with the audio input?

[FaberAST]

In my experience, the signal source needs to be connected to whatever cable is being plugged into the headset jack. Sometimes, it seems to help to even have a live signal on the plug when it is plugged in. Otherwise, the iPod may not recognize that an input is available on the headset connector. It may still take one or two tries plugging in the cable before the iPod switches to the headset for input (it has nothing to do with the software, e.g. SignalScope, since the OS automatically determines where the audio is coming from).

Ben

[Riley Casey]

The solution as it turns out was to draw a little current from the power supply for the headset mic.  An 3.3k ohm resistor shunting the input drew the 2.7 vdc supply down to 1.9 vdc.  The source oscillator is DC blocked by a 10uF capacitor.  The ipod touch showed " Headset mic " on it's audio source display but initially still failed to display an input signal.  After touching the audio input selector it went to " Headset II " and displayed the output of the bench oscillator.  I am building this set up into an XLR to mini plug adaptor cable to allow me to send signal on to the console inputs and receive signal from the monitor output of a console thru a 50db pad , blocking cap & bias resistor all built into the female xlr of the adaptor cable.