Uses Jim Booth's LoRa transmitter hardware to send battery voltage to Jim's LoRa receiver hardware.
The code is based entirely on Jim's transmitter code. Thanks, Jim!
May 2022: Receiver has been modified to receive data of any kind, without knowing what it is, so Transmitter has also been modified to send the new "generic" format of data.
See https://github.com/ba58smith/lora-receiver for instructions on using this system.