ESP32 based IoT Device for air quality logging featuring an MQTT client and REST API acess. Works in conjunction with a VINDRIKTNING air sensor from IKEA.
These instructions will get you a copy of the project up and running on your local machine for development and testing purposes.
You will need a running copy of the ESP IDF SDK. Please follow these instructions:
https://docs.espressif.com/projects/esp-idf/en/latest/get-started/
Be sure that you have the idf.py application in your path and that all environment variables are setup, e.g. by providing a .zshrc file (example for macOS Catalina):
#ESP32 stuff
export IDF_PATH=<your IDF path>/esp-idf
source $IDF_PATH/export.sh
Download or clone the repository to your system
https://github.com/timbocgn/way2dustlogger.git
Firstly you should install all the dependencies for the vue based web application
cd front/webapp
npm install
When this is done, you can build the vue app
npm run build
This will "compile" the app into the build directory where the ESP toolchain will pick it up to store it onto the ESP32 fat flash filesystem, where it is then served by a http server.
When the build is done, you can configure your IDF app
cd ../..
idf.py menuconfig
Under "ESP Dust Logger Configuration" you will be able to define the number of sensors connected and the respective GPIO pins. Please see the wiring instructions for the bootstrap switch and the info LED.
When configured, compile and flash to your device:
idf.py build
...
idf.py -p <your serial device> flash
My WEMOS mini board (see below) is equipped with a CP2104 USB/UART converter and in my case it defaults to /dev/tty.usbserial-00E3A8A2.
Please use
ls /dev/tty.*
to find the device name of your programming port.
A lot of debugging output will be generated which you can see if you monitor the ESP:
idf.py -p /dev/tty.usbserial-00E3A8A2 monitor
- Close the bootstrap switch for more than 10 seconds. The system reboots...
- The LED will blink in a 500ms on - 2500ms off sequence, which indicated that the build in access point is up and running
- Connect your system to this AP's IP-Address - the password is "let-me-in-1234"
- Go to the configuration page, provide your WLAN access point SSID (press 'Scan' to get a list) and provide the password
- Reboot the system (power off and on)
- When the LED blinks in a 100ms on - 100ms off - 100ms on - 2700ms off fashion, the system is connecting to your AP
- When the LED blinks in a 100ms on - 2900ms off fashion, the system is connected to your AP
Please take a look at your router, DHCP server or the monitor output to get the IP address of the ESP32. Point your browser to the IP address to check if the sensors are working.
It might take a while until the Vindriktning sensor reveives its first measurement.
The sensor provides a REST-API for the device. See the postman examples in Dust Logger.postman_collection.json.
pm1is the number of 1um particles per m^3pm2is the number of 2.5um particles per m^3pm10is the number of 10um particles per m^3
Just provide the necessary data in the MQTT section and enable the MQTT client. The sensor will provide the data as JSON struct:
{
"pm1" : 24,
"pm2" : 55,
"pm10" : 14
}
To change the UI it is very handy to you the build in web server of webpack:
npm run serve
It will start a local web server on your machine which forwards the API calls to your device. Please check the vue.config.js file in front/webapp and enter the IP adress the requests should be forwarded to (to the address of your ESP).
Please follow the vue.js guides and how to's on how to change the front end code.
I used a ESP32 MINI board, sometimes called WEMOS ESP32 mini board although it is not a WEMOS board. I bought mine here: https://www.komputer.de/zen/index.php?main_page=product_info&products_id=530 . They are wideley available, just google for it. GPIO2 is directly connected to a SMD led on this board, so this connection has already been been made.
The default configuration is:
SENSOR1_UART_PORT_NUM = 1
SENSOR1_DATA_GPIO = 25
BOOTSTRAP_GPIO = 35
INFOLED_GPIO = 2
The wiring is quite simple as you can see in the hardware/EspDustLogger_schem.pdf file in the repository.
The part with the transistors converts the 5V signal of the sensor to the 3.3V level of the ESP32. There are many articles in the web that it will work without, but this is dangerous as the ESP is not 5V-save.
The button is pulled up to 3.3V and gets pulled down to GND when you press the button. The device will then enter bootstrap mode and open the own wifi ap.
- ESP IDF - The SDK used for developent
- vue.js - Javascript frontend framework used for the SPA
- node.js - Used to compile the vue app
- webpack - Module bundler for the vue app
- pm1006 on github - code for receiving the sensor data
- Tim Hagemann - Initial work - https://github.com/timbocgn
This project is licensed under the MIT License.
- The ESP IDF authors for the perfect source code examples they provide within their SDK
- Bertrik Sikken for his excellent PM1006 class available on GitHub