My City (Medellín, Colombia) is in the middle of a crisis due to high levels of contamination. The creation of a low cost device that anyone can implement will help to create awareness of the problem so we all help with solutions or take personal actions to reduce pollution.
This project uses the PPD42 sensor and an Arduino with WiFi connectivity to connect to Thingspeak service and post data to a Database and Twitter. A more complex version will contain a Humidity/Temperature sensor and a MQ7 sensor to measure CO2.
This version includes a Fan added to the PPD42N sensor to increase the air flow, a 10K resistor from pin 5 of the sensor to GND to improve measure accuracy and the addition of sensor SHT1x to measure humidity and temperature.