Board Manager URL for ESP32:
Board Manager URL for Feather M0 LoRa:
Basically need to just load this config file in 'Additional Board Manager URLs' field in Preferences in Arduino IDE:
Then can select Heltec WiFi Lora (V2) (the board we're using).
WiFi scan worked.
|Initial wifi scan test.|
U8g2 library for Arduino covers a wide range of common displays.
Test code that will scan wifi and display the results on the screen.
Instructable that has a nice set of diagrams of pinouts
They suggest using this LoRa library.
use this LoRa library;
And this example.
Basic RFM95 Receive code for Heltec. Works.
Working code to do basic JSON post to FarmOS here.
ArduinoJSON SerializeJSON documentation.
Using loop-updated variables, code is here.
Using dummy variables, not yet parsing incoming radio, code is here
Feather sends JSON data; Heltec receives, parses, posts to FarmOS; code is here.
Some nice notes here
Deep sleep example code
Able to get about 2 mA in deep sleep using Heltec. ...
.. then turned off lora radio and got 1 mA.
gist of the code to do this is here
Further discussion of low power modes here.
From CNX Software -- looks like they use dozens of nodes here.