Even without any fancy circuitry, these look pretty awesome at night. The project could be improved by adding a transistor to make the balloon illumination brighter, and by more carefully calibrating the air quality sensors to temperature and humidity.
This is a project by Stacey Kuznetsov, Jian Cheung, George Davis and Eric Paulos at Carnegie Mellon University. Photos were taken by Chloe Fan and Iris Howley.
Please feel free to contact Stacey Kuznetsov (firstname.lastname@example.org) if you have any comments or questions.
Step 1: Gather Materials
- Air Quality Sensor from Figaro (I recommend the VOC or the diesel/exhaust sensor, $10/$20 each)
-PICAXE micro-controller - 8 pin ($2.95)
- DIP-socket for the PIC ($1.50)
-Rechargeable lipo battery ($8.95)
-Tri-colored LED ($7.95)
-Either a 10Kohm resistor for sensing VOC or exhaust, or a 100Kohm resistor for sensing diesel
- Weather Balloon ($3.95)
- Access to Helium (you can probably go to a party store, or rent a tank from a welding supply shop)
- rubber band or string to tie the balloon once inflated
- (optional) connector for battery
You will also need to use
- Picaxe starter kit and cable, or some other way to program the pic
- solder/soldering iron
- electric tape
- head shrink /head gun
- pliers/wire strippers
- power-supply or some power sources around 5V to preheat the sensor