Airrohr Firmware

Strip down firmware based on version NRZ-2017-100 of the luftdaten.info airrohr-firmware:

https://github.com/opendata-stuttgart/sensors-software/tree/master/airrohr-firmware

Building and Flashing

Build the image with the build script:

./build.sh

The image is stored in the builds folder.

The flash script flashes the indicated image to the ESP8266 module:

./flash /dev/cu.wchusbserial1420 builds/airrohr-fw-0.3.0.bin

The first argument denotes the device file name, the second argument denotes the firmware to be flashed.

Wiring

• SDS and DHT wiring: https://raw.githubusercontent.com/opendata-stuttgart/meta/master/files/nodemcu-v3-schaltplan-sds011.jpg

Tools

• Arduino IDE
• ESP8266 für Arduino

Arduino IDE Settings

• Board: NodeMCU 1.0 (ESP-12E Module)
• CPU Frequency: 80MHz
• Flash Size: 4M (3M SPIFFS)

Dependencies

The project has the following external dependencies:

• [email protected]
• DHT sensor [email protected]
• [email protected]
• Adafruit Unified [email protected]

Wiring

SDS011

• Pin 1 (TX) → Pin D1 (GPIO5)
• Pin 2 (RX) → Pin D2 (GPIO4)
• Pin 3 (GND) → GND
• Pin 4 (2.5m) → unused
• Pin 5 (5V) → VU
• Pin 6 (1m) → unused

DHT22

• Pin 1 → 3V3
• Pin 2 → Pin D7 (GPIO13)
• Pin 3 → unused
• Pin 4 → GND

Luftdaten.info API Pins

The luftdaten.info API needs for each sample type a specific pin number to correctly match the measurements:

• DHT22 → Pin 7
• SDS011 → Pin 1