Display RF messages from JemRF Flex radio module on the ESP-32 OLED screen
https://www.jemrf.com/blogs/gadjet-chat/wireless-message-monitor-wit-lcd-display
We have modifies HardwareSerial so you can use UART2 (referred to as Serial2 in the code) on pins 12 and 13 (free GPIO pins not use by the Heltec ESP-32). See picture for wiring pinouts.