I recently had a project request to allow a user to experience different rotary encoders and how they might react with digital LEDs. In short, getting encoders wired to a board to directly control the UI in an iOS application. This saved me from having to alter soldered LED counts and allowed logic and animation to take place in easier to update software.
Since the Adafruit Feather 32u4 has onboard BLE, this alleviated the need to use a shield for BLE communication between the board and my iOS application. It wasn’t quite as straightforward as some online documentation would have you believe.
My final prototype was the 32u4 board, two encoders, a rechargeable battery for the 32u4, my phone, and my Swift iOS application. My communication was uni-directional from the board to the iOS application. It’s easily possible to have the iOS talk back to the board, but was unnecessary for my prototype.
If anyone wants my Sketch and source for the iOS application, I can make a stripped down version of those available if anyone is interested. Leave a comment – and if I get enough requests, I’ll take the time to release those – as well as insights gained during the development process.