A GPS unit is a great CAR accessory, but the power cord hanging across the dashboard is an eyesore. Many vehicles have 12V power at the rear-view mirror, with a 2-wire plug. Tap into it to straighten up your view.
In this tutorial, you will learn to print layout templates and silkscreens onto perfboard. This will make populating as well as soldering a lot easier PLUS it looks professional.
The project uses the DHT22 sensor to monitor temperature and relative humidity in an aquaponics system. The data is uploaded to a bare-bones application on Google App Engine and visualized with Google Chart Tools.