When iPhones still had the headphone port, a friend of mine soldered a IR led on top of a minijack, something like this: https://www.rtfms.com/wp-content/rtfms

When iPhones still had the headphone port, a friend of mine soldered a IR led on top of a minijack, something like this: https://www.rtfms.com/wp-content/rtfms-com/LED-pinout.png https://www.rtfms.com/wp-content/rtfms-com/LED-pinout.png Then, with some special app, or even just playing some audiofiles — I don't remember — he'd do the same thing as the device above.