I am trying to use an ESP32-S2 feather board with a separate bluetooth module, the Adafruit BLuefruit LE UART Friend. I previously used this bluetooth module with the Feather M0 Adalogger through UART without experiencing any major problems. Now, the bluetooth module does not even get past its begin function. In fact, in order for my program to even compile, I have to change the UART header and cpp files in the nRF51 library by commenting out Software Serial code (although, I don't actually use software serial) because the esp32 core does not have that library. Is this a matter of cores (esp32 as opposed to samd or avr) or something else entirely?