How would you talk to USB CDC serial port from IOS?

Andrei Chichak · ‎2020-05-08

I've got an STM32F7 device set up as a CDC virtual com port, and I have Windows, MacOS, and Linux talking to it. The device side works nicely, I'm wondering about the iPad side.

I was wondering if there is some sort of framework within IOS/Xcode that would make the VCP available. We've tried a few avenues, and IOS does speak USB CDC but things like ethernet not serial.

Has anybody got something like this working?

Thanks,

Andrei from The Great White North.

Romain LE DONGE · ‎2020-05-25

Hello Andrei

You're right, as of today iOS does not let you talk directly through USB Serial via its lightning connector

Maybe there is a workaround. You can get inspired by :

https://github.com/rsms/peertalk that does "USB communication" between iOS and macOS via lightning (this is used by Duet the desktop extending app)
https://github.com/fetisov/lrndis which is described as "stm32 ethernet over usb (rndis + lwip)", but I haven't tested it

If you find a solution to do communication between STM32 and an iOS app, i am also interested :)

Best regards,

Romain