StofAnanas

Project StofAnanas
Showing particulate matter concentration as a coloured light
Status	In progress
Contact	bertrik
Last Update	2019-06-18

The idea

Show current airborne particulate matter concentration using a LED light in a lamp, inspired by http://stoflamp.nl The data that the LED colour is based on is simply retrieved over WiFi from the luftdaten website.

This lamp is a plastic pine apple ("ananas"), bought at the "Action" store.

Features:

• The lamp shows particulate matter concentration as a colour, from dark blue for low concentration and bright pink for high concentration
• The lamp retrieves the PM value over wifi from the the luftdaten website
• The luftdaten measurement station can be entered at the same time as when wifi credentials are entered.
• should be compatible with Wemos D1 RGB LED shields, but has not been tested yet.

Ideas/nice to have:

• The lamp "breathes" by varying the intensity over time, e.g. a cycle of 10 seconds where the light dims a bit and brightens a bit
  • perhaps increase the breathing rate for higher PM
  • perhaps modulate the colour saturation instead of intensity
• Automatic determination of location by means of wifi location, so you don't even need to input a luftdaten monitoring station id (do this on every startup for example)
  • example query to get (very coarse) position data from Mozilla:

 https://location.services.mozilla.com/v1/geolocate?key=test

• • example query to list of sensors centered around a location from Luftdaten:

 http://api.luftdaten.info/v1/filter/area=52.022,4.692,1.0

• Remote control over IR

Operation Manual

configuration

Programming

• connect everything up as indicated under 'hardware' and connect the Wemos D1 board to the USB port of your development PC / laptop
• flash the software into the Wemos D1 mini, typically from the command line using platformio:

 pio run -t upload

Configuration

• on https://netherlands.maps.luftdaten.info find the particulate matter station you want to follow and note the number of the station, for example "12246"
• on a mobile phone, connect to the "ESP-STOFANANAS" network, and select login
• when presented with the captive portal, select a WiFi network, fill in the WiFi password, AND ALSO fill in the number you looked up earlier, press SAVE
• NOTE: when the configuration is ongoing, the LED will be YELLOW, it turns OFF when configuration is done.

Usage

• POwer up the lamp while in range of the WiFi network you configured
• The LED should start yellow (connecting to the WiFi), then briefly change to OFF (retrieving PM value from Luftdaten), then change to a colour representing a PM concentration
• A new PM measurement is retrieved every 5 minutes.

Hardware

pinout

The lamp is controlled by an ESP8266, a Wemos D1 mini board. The LEDs is an RGB LED with built-in PL9823 controller.

Connections (using dupont female-female):

• LED Din to Wemos D1 mini pin D3
• LED Gnd to Wemos D1 mini pin GND
• LED Vdd to Wemos D1 mini pin 5V

Software

Source code is available on github.

To compile and upload it, I use platform io:

 pio run -t upload

You can also compile it with the Arduino IDE, libraries used:

• WiFiManager (v 0.14) is used to manage WiFi connection to the local AP
• ArduinoJSON (v 6.11) for the parsing the luftdaten response
• FastLED (v 3.2.9) is used to control the RGB LED

Luftdaten interface

The current measurement value of a particular sensor can be determined by parsing the JSON messages retrieved over a REST interface, by performing an HTTP GET on URL

 http://api.luftdaten.info/v1/sensor/<sensor-id>/

where <sensor-id> is the database id used by luftdaten (and visible on their map). The trailing slash in the URL is significant.

For example:

 http://api.luftdaten.info/v1/sensor/12246/

The software looks for the "P1" (PM10) sensor value in the JSON message and averages all measurements it finds (usually the current one and a previous one).