[DisasterRadio] Experimental nRF52 support

[samuk at disroot.org]

Bernd has done some very experimental support for the low power nRF52 which he was happy to share

He wrote

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Just for fun, I ported the DisasterRadio sources to work on a Nordic nRF52 board. Of course there is no WiFi at all with the nRF52, but they are fantastic in low power consumption. In another (customer) project I have a nRF52 with a Semtech SX1262 LoRa running for 5 days from a 1000mAh battery while sending LoRa packages every 30 seconds.

The code is working with some restrictions:
- Only BLE or Console to connect to the node
- Only tested with an Semtech SX126x LoRa transceiver, I have no RFM95 modules.
- No SD card history support
- No OLED support (working on it, needs a different library)
- LoRa layer 2 hash support disabled (not used at the moment anyway) because the nRF52 has not enough RAM to hold the (very big == 10kB) table for it.
- no GPS support because the nRF52 has only one HardwareSerial and I didn't try the SoftwareSerial yet.

Sources are up. https://github.com/beegee-tokyo/Disaster-Radio-BLE---nRF52832

Please make sure you keep the lib folder, because there is an adapted LoRaLayer2 file.
You will have to adapt the platformio.ini file. Right now the nRF52 has a USE_SX1262 flag. To run it with a RFM95 board you have to remove that and adapt config.h with your GPIO settings.

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I think this might work with https://coolcomponents.co.uk/products/adafruit-feather-nrf52-bluefruit-le-nrf52832 and 

Kind of related to the Wind discussion, in so far as the cheapest energy you'll get is efficiency..

Thanks

Sam