#96 Arduino C++ - ESP-NOW changes and issues caused by ESP32 v3.0.0

In 2024The ESP32 board library changed to version 3.0.0
This was a big change and contains modifications to functions that break existing code.
ESP-NOW has some issues including the error to the line:

esp_now_register_recv_cb(OnDataRecv);

That now gives the error:

Compilation error: invalid conversion from 'void (*)(const uint8_t*, const uint8_t*, int)' {aka 'void (*)(const unsigned char*, const unsigned char*, int)'} to 'esp_now_recv_cb_t' {aka 'void (*)(const esp_now_recv_info*, const unsigned char*, int)'} [-fpermissive]

This video works through some of the issues I have found with ESP-NOW and shows how to fix the code as well as showing how to put gurads into code for those who have to compile to the old and new ESP32 library.

Code is available for download at:
http://www.digitaltown.co.uk/70ESPNOW...