Cooper Bills and Anish Borkar, two EE students at Cornell, have created The Handy Lab Buddy, a multifunction device, based around an ATMega 644, that measures voltages, logic levels and frequencies, and then “speaks” the results via a wavetable. They write:
The Handy Lab Buddy is a tool every ECE should have. The four features of this tool include a talking voltmeter, logic probe, voltage averager, and frequency measurer. As a cheap and accurate device that outputs whatever being measured through speakers, it’s one of its kind and an essential tool for lab work.
The “voltage averager” feature is particularly interesting. It takes multiple voltage samples, and then outputs the average, as well as the min and max levels, over the speaker.
If you want to do this project yourself, they provide the schematic and code on the website. Alternatively, you could try something similar with an Arduino and a WaveShield.
Great job, guys!