For all ya geeky weight watchers out there! Here’s a project that will measure your body weight, connects through wifi and records each result onto google docs – neat isn’t it?
The project was built out of an Arduino Uno, a Wifi shield, a Velleman scale (that was ripped open for this project) and an LCD shield to display how much you weight. The Velleman’s load cells are hooked up into the arduino uno’s analog to digital converters through a INA125 chip that is specifically build for load cell applications like weighting scales. The INA125 sources the precision voltage that is fed into the load cell which acts like a resistor bridge, the differential result would be in a few milivolts thus the INA125 also has an amplifier that amplifies the signals 500 times so that it can be detected by the Arduino Uno’s analog to digital converter. The uno then builds up a packed data using the APP_WISERVER library to connect with wifi and then google docs for the recording of the weight data. There are some critical steps that need to be properly configured for the publishing to google docs to work – though its a bit tricky this project is worth the effort, I’m actually thinking of building one for myself.