Frequency Counter

( Using PIC16F84 )

 

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School:          University Of Balamand - North Lebanon   

Course:            EE351 - Microprocessors

Instructor:     Dr. Nicolas Haddad - Assistant Professor in Electrical Engineering (Ph.D)

Students:        Karim Khoury (EE),  Edgard Nasr (CE)  &  Ramzy Jreige (CE)


Description

The circuit above measures the frequency of a TTL waveform from 0 to 9999 Hz. The PIC16F84 microcontroller from Microchip is operating at 4MHz (crystal).

RB0 is used as input and the microcontroller counts the positive or negative going edges of the waveform on an interrupt basis every 1 second.

As it is shown, the display is multiplexed and controlled by the transistors connected to RA0-RA3. Each display is refreshed every 4ms.

The 1k resistors at the base insure the saturation mode  operation of the transistor. 150 ohm resistors are used to limit the current for the seven segment displays.

The 7-seg is connected to the MCU via PORTB as follows:  (RB7 - RB1) --> (a - g)  respectively.

 

Hardware Components

 

Assembly Code

 Click Here for the program code

 Note: This program was assembled using the original software from Microchip, MPLAB

 Please send comments here if any.

 


 

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This page was created by Karim Khoury

 on February 11 - 2002