LoRaWAN pm sensor

This sensor measures the fine dust concentration in the air and sends data over TTN LoRaWAN network. Via a data forwarder the data is pushed to the luftdaten servers

Project description

This is the firmware for a Influencair LoRaWan sensor based on a Honeywell HPM series pm sensor, ESP8266 and RFM95W. For the LoRaWAN network we use The Things Network.

This repo contains the firmware and the helper tools necessary for flashing these sensors.

This sensor assembly is based on a NodeMcu ESP8266-e12, RFM95W lora transeiver, HPM pm sensor, DHT22 humidity/temperature sensor.

Requirements

• Node.js
• Yarn dependencie manager
• IDE (VS-Code, Atom) with Platformio

Hardware

HPM sensor

- pin 1: Not connected
- pin 2: NodeMCU UV (USB Voltage = 5V)
- pin 3: Not connected
- pin 4: Not connected
- pin 5: Not connected
- pin 6: NodeMCU D3
- pin 7: NodeMCU D4
- pin 8: NodeMCU GND

DHT22 sensor

- pin 1: NodeMCU UV (USB Voltage = 5V)
- pin 2: NodeMCU D1
- pin 3: Not connected
- pin 4: GND

RFM95W

- GND : GND
- MISO: NodeMCU D6
- MOSI: NodeMCU D7
- SCK : NodeMCU D5
- NSS : NodeMCU D8
- RST : Not connected
- GND : GND
- DIO2: Not connected
- DIO1: NodeMCU D2
- DIO0: NodeMCU D0
- 3.3V: NodeMCU 3.3V
- DIO4: Not connected
- DIO3: Not connected
- GND : GND
- ANT : ANTENNA

LoraWan Setup

You will need an account at https://console.thethingsnetwork.org and create an application. In the application go to payload formats and add this decode function:

function Decoder(bytes, port) {
  var decoded = {};

  // Decode bytes to int
  var p10int = (bytes[0] << 8) | bytes[1];
  var p25int = (bytes[2] << 8) | bytes[3];
  var hum = (bytes[4] << 8) | bytes[5];
  var temp = (bytes[6] << 8) | bytes[7];

  // Decode int to float
  decoded.pm10 = p10int / 100;
  decoded.pm25 = p25int / 100;
  decoded.humidity = hum / 100;
  decoded.temperature = temp / 100;

  return decoded;
}

Next create a new 'ABP' device in TTN console https://console.thethingsnetwork.org/applications/your_appID and copy the 'deviceId'

Use

1. open this project within Platformio.
2. Run yarn in the project root
3. Go to TTN console and open your TTN application
4. Copy your appID
5. Set your TTN appID in your environment variables export appID=your_appID
6. Copy your application accessKey, make sure this key has access to 'devices' & 'settings'
7. set your TTN accessKey in your environment variables export accessKey=your_accessKey

Flash a sensor

1. Create a new 'ABP' device in the TTN console and copy the 'deviceId'
2. Run deviceId='deviceId' node getDevice.js

By Influencair