Since the pic16F676 have 10bit 8 channel on chip analog to digital converter module, i have used one channel for measuring the input voltage and others are used as digital input/output pins.
This project I use CCS C compiler to programming.The main routine continually read the input voltage on RA3 and convert to 7-segment code while TIMER1 set to timer for interrupt every 5mS for scan all digit about 66Hz(only one digit turn on at every 5mS). In convert digital value to voltage routine we must scale the value with the full scale display in this project I want full scale display at 30V so the input voltage must scaled with 30 and display resolution is 29mV or 30/1023. source code and schematic available here.
Tags: PIC 16F676 projects, digital voltmeter, voltmeter using PIC, digital circuit, mini circuits, mini projects, analog to digital converter, microcontroller projects, PIC projects, PIC 16F676 circuits