FeinstaubLoRa uses an ESP32-based Heltec Lora 32 module and a SDS011 particle sensor to measure the amount of particles in air and reports these measurements to TheThingsNetwork.org. It uses MCCI / LMIC for LoRaWAN communication and u8g2 to control the OLED screen.
The source code can be compiled using PlatformIO.
The code does not support proper deep sleep and requires a constant power supply.
| SDS011 | ESP32 |
|---|---|
| 5V | 5V / Vin |
| GND | GND |
| TX | GPIO 13 |
| RX | GPIO 21 |
Make sure to use the TX/RX labels on the back of the SDS011.
The SDS011 takes a lot of power to start the fan motor.
It is beneficial to add a 1000µF (or similar) capacitor between 5V and GND directly at the sensor.
You can also desolder or short the 1N4148 diode on the ESP32 board.
Configure a new application and register a new device.
Set the device to OTAA mode, with "Frame Counter Checks" disabled (settings-page on the device-menu).
Frame Counter Checks are not supported, because the ESP32 can't store the last frame counter value permanently (without constant flash writes or external battery-backed SRAM/RTC).
Device EUI, Application EUI and App Key need to be copied into config.h. (copy config.sample.h and rename it config.h first). Make sure to copy the right endianess (MSB/LSB), this can be switched in the TTN web interface.
The TTN Decoder needs to be copied into the "Payload Formats" tab page (in the application-menu).