This is simple 3 Digits Digital Volt Meter by 7 Segment Display. PIC16F676 used to read analog signal(voltage) and display the value on 3-digits 7-segment.
Hardware
As we know the most of PIC microcontroller has 8-bit/10-bit on-chip Analog to Digital converter module. In this project I use PIC16F676 which have ADC 10-bits 8 channel but this project use only one channel for measure voltage input for other pin set as digital I/O.
Schematic
From the schematic above the input voltage divided by R1 and R2 (voltage divider).VR1 parallel with R2 use to adjust appropriate display full scale voltage.The divided input voltage will connected to AN3(RA4) which set as analog input.
RA0, RA1 and RA2 set as digital output to turn on/off the digits in scan dispay routine.
RA3 not use in this version and it was input only
RC0-RC5 and RA5 use to drives the segment of dispay(7-segment decoded by software)
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