1. For Shits and Giggles: Optimized Sequential Sampling from Multiple Sensors (Arduino)

    By treating sensor sampling as a statistical challenge one can reason about how many samples to take from each sensor given a limited time interval for sampling (eg. 1s). It turns out that 30 samples per sensor is fine, and indeed, even one sample per sensor each second works. But life isn't only about usefulness, read on to follow my messy thoughts and perhaps learn a thing or two along the way.

    local_offer optimization, arduino, mq131, winsen, ze25-o3, sensor, ozone, code, no2

  2. Measuring NO2 with a Winsen ZE25-O3 Ozone Sensor

    We set out to measure ozone but ended up getting better results measuring NO2. In the absence of a reference sensor, we correlated our measurements with the closest city air quality monitoring station. We used the correlation as a metric for how well the sensor was performing. Finally, we also combined this with studies about the indoor/outdoor ratio of NO2 to estimate indoor NO2 concentration.

    local_offer winsen, sensor, code, ze25-o3, ozone, no2, arduino

  3. Large-Scale Outdoor Air Purification

    With the great consequences that dirty air has on people, there's no surprise that experts have attempted to solve it by attacking the problem of pollution from different angles. This blog post is a brief exploration looking at examples of large-scale outdoor air purification.

    local_offer large scale, outdoor, delhi, beijing, india, china, water cannon, pulsed radio frequency energy, tio2, solar-assisted large-scale cleaning system, xian