A few weeks ago, I started work on internet connected bathroom scales, and I finally received my custom PCB’s to finish the job. I discovered that most digital scales use strain gauges to calculate the amount of weight on them, meaning there is almost no mechanical movement making them perfect to interface with.
The set of scales that I purchased handily had the Wheatstone bridge markings on the PCB silkscreen, which made connecting up the ADC nice and easy. Continue reading Hacking bathroom scales with an Arduino – PCB