A simple example how to use Feather 32u4 with RFM95W modem and TTN.

Uses the LMIC library from https://github.com/matthijskooijman/arduino-lmic

This sample deviates from the original sample by adding

while (!Serial) {
 delay(1);
 }

after the initial serial port configuration as well as

LMIC_setClockError(MAX_CLOCK_ERROR * 1 / 100)

which is called after LMIC_reset. This option increases the size of the receive window by 1%.

To use the LoRa32u4 II from BSFrance/DIYMail with LoRAWan you have to bridge the DIO1 port with any digital input (pin6 with the configuration in this example). If you use the FSK mode you've to connect DIO2 with any digital input (for example 5) and provide the dio pin configuration too.

• DIO0 (connected internally to pin 7) is the TxDone/RxDone pin
• DIO1 is the RxTimeout for LoRa mode
• DIO2 is the TimeOut for FSK mode

If the DIO1 connection or configuration is missing one can see the join / join accept messages as well as the first data message but not any more transmits.