The Magic Home LED WiFi Monochromatic (1CH) Controller is a very cheap device for controlling a 1CH LED strip or wire which are often used for Christmas trees. Since it is using an esp8266 chipset, it can easily be flashed with an alternative firmware.

IKEA has released an air quality sensor which measures the PM2.5 density in the air and shows the classification by a green, yellow or red LED.
For my surprise, it is a dump sensor with no ZigBee support like some other devices IKEA has released in the past months.
So let's make the sensor smart with the help of ESPHome and Home Assistant and add an additional eCO2 sensor.