Access 30-Pin connector with code

Question

I am trying to set one pin of the old iPhone 30-Pin Connect from low to high so the best would be from 0V to 3,3V. Is that possible with a simple PodBreakout board like this?

https://www.sparkfun.com/products/8295

If not can you send a constant voltage out of the iPhones audio jack (This could be a good method too, cause now apple used its 9-Pin Lightning Connector).

I already searched the web, some say you have to jailbreak your iDevice, some say you need an authentication Chip, and some say it works flawlessly without an authentication chip, but I cant find any help online.

Thanks

Answer 1

You can't "send a constant voltage" out of the audio jack. There is a series capacitor there that filters out DC and very low frequency signal components.

To get proper help on this you can apply for the MFi program. I think it's free for educational purposes. It's under 100$ for sure. There is an NDA involved.

If you want to avoid the MFi you can always use BLE to communicate with periphery.

Or try to implement software FSK (or DTMF) modem on one side and a hardware one on the other side (using the audio lines).

Since it seems you simply want so see a binary (on/off) signal - you could generate a fixed pitch tone in the app (2kHz for example) and use a narrow-band filter on the hardware side (audio-jack connection).

Or maybe (to make sure your app is present on the other side a 2kHz tone would mean 0 and a 4kHz tone could stand for 1.

The authentication chip (and an MFi license)) you are talking about is needed when you try to communicate with the iOs device:

• via BT (excluding BLE)
• via USB (30 pin connector or lighting connector)
• via UART (30 pin connector or lighting connector)