When you need a versatile, multifunctional instrument for measuring six different types of parameters in the lab, the venerable microcontroller PIC16F886 is a suitable solution to perform such a task. The microcontroller in this design idea can perform the following instrument functions: voltmeter, thermometer, pulse counter, frequency counter, period meter, and tachometer.
This design requires only a three-digit numerical LCD; its total current consumption is less than 1 mA. To drive the LCD, the microcontroller’s pulse-width modulator (PWM) generates a signal to drive the common input on the LCD. The PIC drives the LCD by inverting the data on its ports with respect to the common input.