This is an Arduino sketch for the Adafruit ItsyBitsy 32u4, which provides encoding and decoding of Morse code over both the serial port and an emulated USB keyboard.
This code is based on an earlier project that specifically targeted the TI MSP430 LaunchPad. This should still work on the MSP430 as well as other Arduino-compatible microcontroller boards, except that the keyboard functionality (if enabled) relies on specific features of the ATmega32u4.