The tachometer uses an eight blade rotor attached to a motor shaft with a Hall-effect sensor. It is designed as a stand alone peripheral to a host. The tachometer board has a four digit seven segment display (from Three-Five Systems). It communicates with the host over an RS485 half duplex link, via a Maxim MAX3100 UART. The code contains both UART and seven segment drivers. (Hardware schematic included in PDF format)


¹Member submission to the TechTools Discussion List:  piclist@tech-tools.com