This is a simple application of internal 10-bit ADC (analog to digital converter) of PIC16F676 microcontroller.you can use this circuit to measure up to 30 v dc. the possible applications are on bench top power supply or as a panel meter in various system.
MICROCHIP’S PIC16F676 is the heart and brain of this circuit .the internal adc of the mcu with a resistor network voltage divider is used to measure the input voltage . then 3 digest of comm anode 7 segment display is used to display final converted voltage. as you can see in the schematic the displays are multiplexed with each other . means we switch on one display and put the corresponding digit on this while other two displays are off this cycle go for each of the display.
Panel Voltmeter Using PIC16F676 - [Link]
This project is a 3 digit – digital voltmeter based on PIC16F676. PIC is reading the analog voltage using internal 10-bits ADC and display the value on 3-digits 7-segment displays. Check project details on the link below.
3 digits Digital volt meter – [Link]
Jos van Eijndhoven have designed a 3 channel fan motor controller based on PIC 16F676 microcontroller. Mcu reads temperature from sensors and outputs PWM modulated signal to each output so the speed of fan is controlled accordignly. Three on board potentiometers controls the start up temperature for each channel. The speed of fan is controlled linearly according to temperature and drops slowly when temperature goes down fast to avoid instability. For the output transistors BUZ72 are selected and temperature sensor is LM60. PIC code is written in C and compiled to hex using free CC5x compiler.
Three channel fan speed controller for PC - [Link]