AQLoRaBurk

This Arduino sketch reads BME280 or BME680 environmental sensor and SDS011 particulate matter (PM2.5/PM10) sensor values.

If they are correctly wired they should be automatically detected.

Data is transmitted over LoRaWAN network using ABP activation. Default sending interval is about one minute.

SDS011 values are read once in second, put into an array and when it is time to send the data, QuickStats is used to calculate min, max, avg and mean of PM10 and PM2.5 values.

BME680 is read once in 30 seconds (default).

TTGO ESP32 LoRa V2 and V2.1 have been tested to be functional with this code.

Surprisingly this code has been very stable: dozens of deployments have been running months without issues.

Gettings started

Arduino libraries

Install the libraries below using Arduino IDE's

Sketch->Include Library->Manage Libraries...:

• Adafruit_Sensor
• Adafruit_BME280
• Adafruit_BME680
• Adafruit_SSD1306
• MCCI LoRaWAN LMIC library by IBM, Matthis Kooijman, Terry Moore etc.

Define radio type in LMIC lib

Do not forget to define the radio type correctly

#define CFG_eu868 1

in libraries/MCCI_LoRaWAN_LMIC_library/project_config/lmic_project_config.h or from your BOARDS.txt.

The code

1. Clone this repository
2. Copy settings-example.h to settings.h
3. Check that NWKSKEY, APPSKEY, DEVEUI and DEVADDR have correct values in settings.h.
4. Open AQLoRaBurk.ino, compile and upload the code to the board

LoRaWAN

Check very carefully all LoRaWAN network related values in settings.h.

Data encoding

All data is put into a byte array which may look like this: 2a2c0021002c002800300056003b0000.

An example how to decode it using python can be found in https://github.com/VekotinVerstas/DjangoHttpBroker-Thingpark/thingpark/parsers/aqburk.py

Wiring

Check pin numbers from settings.h:

// I2C settings
#define SDA 21           // Connect to BMEx80 SDA
#define SCL 22           // Connect to BMEx80 SCL

#define SDS011_RXPIN 39  // Connect to SDS011 TX
#define SDS011_TXPIN 36  // Connect to SDS011 RX

In addition:

• Connect 5V and GND to correct pins in SDS011.
• Connect 3V3 and GND to correct pins in BMEx80.

Known issues

• LoRaWAN spreading factor is hard coded (SP7)
• Only LoRaWAN ABP is supported. If you need OTAA, just implement it and make a pull request