I would like to use a Board to interface with my iPad via BLE and also to power it via a LiPo battery. Which one would you recommend?
I have tried a ESP32 from Heltech in the past and had no end of trouble getting it to work. Wifi was good but no BLE.
I have used Teensy a lot because they are so fast for audio but the application I have in mind is not so speed critical. I will just be sending MIDI sporadically from foot switches.
I prefer to use C rather than python.
You can certainly use an Arduino off a LiPo, you’ll just need to make sure that the voltage that it’s kicking out is in the appropriate range for your board. In this case, it will be the same as a Uno R3, I’ve linked specs for it below from Arduino’s site.
As Oliver suggested, using a Shield or Boost converter to get the appropriate voltage for it off a single-cell is likely easiest. Just remember that you must use an external supply from 6 to 20 volts. If supplied with less than 7V, however, the 5V pin may supply less than 5V and the board may become unstable. If using more than 12V, the voltage regulator may overheat and damage the board. The recommended range is 7 to 12 volts. But obviously you’ll only need 5V over the USB connection, just be sure with your project it can kick out enough current to maintain that: