Question

I am building an assistive iOS app for a kid that uses a switch to control his computer (a simple button that can send only one massege to the computer).

I am looking for a way to connect my app to a switch that can send click events to my app.
It can through by BT, IR or even through the earphone connection (headset port).

(BTW he can not use the iOS screen as the switch).

Any ideas ?

Answer 1

A BT connection requires you to be a certified MFi developer, and that requires money and a real company.

The headphone port would be a great place to interface with. You could wire a simple switch over the microphone line and ground line which, I think, would create a square wave duty cycle for on and off. I’ve done something similar where we used the headphone port to communicate to a microcontroller through a sound wave that was then converted to 16 bit packets and used to control additional hardware and also give feedback from that hardware.

Another option is a wifi connection, an arduino with a wifi shield and the button on that.

Edit:
The more I think about it, the more I would say use the headphone port. It will be super cheap, the programming to detect the presses will be really easy, and this will probably be the fastest way to achieve your solution. Provided you can solder.