People or Object counter Circuit diagram using IC 555 and IC 4026


People / Object counter circuit have a wide variety of applications in Banks, Hospitals, factories etc. This project focuses on building an effective counter using IR as a sensing element and capable of counting from 0 to 999. This project uses Two simple IC’s ( IC 555 & IC 4026 ) with IR transmitter and Receiver to detect the incoming people/object.

This Project comprises of Three parts

  1. IR Transmitter
  2. IR Receiver
  3. 7 Segment drivers



Freq = 1.45 / ( R3 + 2R1 ) C2IR transmitter was wired around Astable multivibrator using IC 555. As we all know that multivibrator produce square wave pulses and we gotta fix the frequency of the output signal as 38 Khz since we are about to use TSOP 1738 an Infra red sensor which is capable of detecting signals of 38 Khz. The frequency of the astable depends on R1,R3 and C2. So lets do some math

         = 1.45 / (470 + 2 * 1690 ) * 100 * 10 

         = 37.6 Khz

So we have fixed the IR frequency of 38 Khz and now Transmitter part is done.

Please note that i have used a simple IR transceiver module (brown board  – right top) for this project to make things simple. You can use use IR module like i did if you have any. If not build the IR transmitter using IC 555 as shown in above circuit. The receiver part was given in the below circuit diagram.


people-object-counter-circuit-diagramThe sensed output was fed into trigger input of the monostable multivibrator using IC 555. As we all know that Multivibrators gives high output when low signal as fed into its trigger and low output when high signal is fed. Two multivibrators was cascaded to prevent multiple increments in the counter since using a single multivibrator changes the output with every low to high or high to low transition in trigger pin.The above circuit diagram comprises of both Infra Red Receiver as well as 7 segment driver. The IR signal is sensed by TSOP 1738 which is capable of sensing the IR signals of 38 Khz frequency. This TSOP will give high signal as output when IR signal is sensed and low signal when IR falls on it. The third pin of the TSOP gives the output and its fed into next stage of the circuit.

                                                                                                                            IC 4026

Next stage of the circuit is 7 segment drivers which is done by three IC 4026 which is a 7 segment display decade counter. This IC is capable of incrementing the digits in 7 segment with clock input in the CLK pin. The output from the monostable multivibrator forms the clock source for this IC 4026. Read more about 7 Segment interface with IC 4026.


The transmitter and Receiver was initially aligned and this makes the TSOP 1738 to give low signal to the multivibrator which in turn gives high at the output and this forces the 2nd Multivibrator to give low signal to the CLK pin of the right most IC 4026. When the IR beam in interrupted the TSOP gives high output which in turn makes the Multivibrator 1 to give low signal trigger to the 2nd multivibrator. 

The low signal input pushes the output of Multivibrator 2 to high state thereby a successful transition occurs and this forms a single clock pulse input to the IC 4026. Thus this makes the IC to increment a single value in the 7 segment. Now cascading three segments will enable us to display count up to 999 which was done by connecting the CO (Clock Out) pin of the IC 4026 to the input clock pin of the preceding IC 4026.

Whenever IC 4026 finishes counting from 0 to 10 it gives out a logic transition in its CO pin which sources the clock for preceding IC at CLK pin which in turn increments the value by 1. By this way three IC’s work together to display digits from 000 to 999. 



  • You can increase the count value by adding 7 segments along with IC 4026 by connecting the CO pin output of the Preceding IC to its CLK pin.
  • You must use two multivibrator or else you will obtain two increments for a single incoming person/object.
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Frank Donald

Frank Donald

Junior Network Engineer at Tata Communications
Frank Donald is an Electronics and Communication Engineer who loves building stuff in his free time. Video games, blogging and programming are the things he loves most
Frank Donald

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38 Comments on "People or Object counter Circuit diagram using IC 555 and IC 4026"

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Dave Johansen

Just a quick question, your schematic does not show any current limiting resistors between the 4026 and the 7 segment LED, but I see them in your video. I’m assuming they should be in the schematic as well? any ideas as to value of these resistors? Thanks


Hi sir,
Ur work is amazing if you don’t mind would I be able to get the codes?It will be really a big help for me from u.I need the codes to continue with the project.
Could you kindly please send it to my email:


Hi sir it would be really a great help if you could send the codes to my email( I really need your help.Thank you very much!


sir can i get full circuit build video please?
if you have?
please send to my mail


Hello boss your using only two 555 ic where is another one?


Many of us getting confuse in connection of transmitter to receiver unit .like where we have to connect ir module.


Hey Frank! can you please upload the layout of this circuit, so it will be easy for students to understand and make it. Also how to replace the IR transmitter circuit in the video with the TSOP 1738. Or just post the connection of your IR transmitter circuit with the main circuit. Please help me as I’m making a project on this. Thanks!


hello sir….
resistor shown in video in between ssd and driver ic but shown in the circuit digram…
plz tell me the values of resistor used


Which type of 7 segment display we have to use for this project common anode / common cathode or we can use both?


Hello, Can You make connection in video with showing all equipment ?
It will be very helpful for all students.

Thank You.


Hello Frank,

First of all I Like your post. It such a very nice and helpful. I need just only two help.

Help 1. Kindly mention all equipment name ( with used quantity ) in the post so I and other people can get it easily.

Help 2. Please also cover all connection in the given image so we fell it easy to connect.
comment image

Thank You. I hope you will review my request and really need your help.


kamulegeya sulaiman

hey, i am using the op amp lm358 as comparater, and a black photo diode. my circuit gives zero response and the seven segment displays show 08! its my project and do therefore need your help. thanks.