This tachometer is based on Atmel ATmega8L microcontroller and Nokia 5110 LCD LPH7366 for measuring rotation speed of any rotating things. A photo sensor is functioned by a photoresistor that is used ...
Does your drill go as fast as the manufacturer says it will? Well, you’d need a tachometer to figure that out. They’re not that expensive to buy, but as [Elite Worm] shows, they’re not that expensive ...