Note for Platform IO using ESP32 LittleFS HOWTO Fix Multiple Definitions Linker Error HOWTO Use analogRead() with ESP32 running WiFi and/or BlueTooth (BT/BLE) ...
Currently, one IRQ needs to be executed for each byte and the bits are read manually. A while (true) reading from the pins and doing the handshaking might be better suited. A FIFO-buffer should be ...