The air pollution sensors are now up and running. You can follow them on Twitter.
Sensors quickly installed
Levels are read straight from the LTC2496 ADC, with 65536 being the maximum level, corresponding to a voltage of 1.65V at the output of the sensor. The sensors (TGS2600 and TGS2602 from Figaro) are powered at 3.3V through a 1k resistor. The sensor heaters are also (under-)powered at 3.3V, this seems to work even though it is out of the specs.
A new Twitter post is made every time a value varies by more by 30%, compared to the last posted value.