I don't know if I posted this in the right topic, but here goes.
I'm doing a project for school and I need to connect an arduino together with a pair of headphones to a smartphone (iPhone or Android). And I've connected a force sensitive resistor to the headphone and I need to send a signal from the arduino to the phone when it senses the headphones are taken off.
I just don't know what to send to the phone. I know the if statement needed for when the sensor drops to a certain value. http://lifehacker.com/5904280/diy-headphone-adapter-adds-pause-play-and-a-microphone-to-any-smartphone-headphone-jack The youtube movie on this webpage kind off sums up what I want to do. I just want to make the arduino act as the button.
I hope you can help me!