ttnenschede_env_node

Description :

• A low power BME280 based enviromental datalogger node for the ThingsNetwork with deepsleep support and variable interval using a LMIC ABP. Compatible with https://github.com/ph2lb/LoRaWAN_TTN_Env

Revision :

• 2018-apr-11 1.0 first "beta"

Hardware used :

• Arduino Pro-Mini 3.3V
• RFM95W
• BME280 sensor.

Software and libraries used :

• Cayenne LPP
• LMIC https://github.com/matthijskooijman/arduino-lmic
• LowPower library https://github.com/rocketscream/Low-Power
• MiniCore loader https://forum.arduino.cc/index.php?topic=412070 https://github.com/MCUdude/MiniCore To use a brownout detection of 1.8V.
• special adcvcc library from Charles (see : https://www.thethingsnetwork.org/forum/t/full-arduino-mini-lorawan-and-1-3ua-sleep-mode/8059/32?u=lex_ph2lb )
• BME280 library https://github.com/finitespace/BME280

For licenses of the used libraries, check the links above.

Aditional note :

You can use Cayenne LPP ofa HTTP integration on the TTN with the decoder / payload function below. :

function Decoder(bytes, port) 
{
  var retValue =   { 
    bytes: bytes
  };
  
  retValue.batt = bytes[0] / 10.0;
  if (retValue.batt === 0)
     delete retValue.batt; 
 
  if (bytes.length >= 2)
  {
    retValue.humidity = bytes[1];
    if (retValue.humidity === 0)
      delete retValue.humidity; 
  } 
  if (bytes.length >= 3)
  {
    retValue.temperature = (((bytes[2] << 8) | bytes[3]) / 10.0) - 40.0;
  } 
  if (bytes.length >= 5)
  { 
    retValue.pressure = ((bytes[4] << 8) | bytes[5]); 
    if (retValue.pressure === 0)
      delete retValue.pressure; 
  }
   
  return retValue; 
}