Object counter using LDR and calculator
To make an object counter we can use a simple dark detector circuit and a normal calculator. Pole and NO (Normally Open) terminals of a relay have to be connected to the two pins which are used to activate ‘=’ key of calculator.
As we block the light falling on LDR, the calculator starts counting.
For the calculator to work as a counter, we first need to press ‘1’ and ‘+’ keys.
All calculators may not work as counter, you need to check with the following steps:
a. First press 1
b. Then Press +
c. Then keep on pressing =
Each time when you press “=”, the calculator should increase the numbers and display 1,2,3,4… and so on. If your calculator displays “1″ every time you press “=”, then your calculator cannot be used as counter.
In our circuit, we use relay to connect two wires of ‘=’ key that eventually increases numbers on calculator.
TESTED and VERIFIED
We have recently released a 3 digit digital object counter kit. You can buy the kit at BuildCircuit store.
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3 Digit Digital Object Counter ASSEMBLED Kit With Infrared Transmitter And Laser Module
US $14.95Read more
3 Digit Digital Object Counter ASSEMBLED Kit With Infrared Transmitter And Laser Module
US $14.95This is 3 digits digital object counter kit for electronics beginners and hobbyists. It is the upgraded version of our previous 2 digits and 3 digits object counter.
You can use this 3 digits digital object counter for counting objects or people entering in a room. It can be used by engineers for learning about digital counters.
This DIY digital object counter works with VS1838 infrared receiver and photoresistor and there are three seven segment displays displaying numbers from 0 to 999. An IR transmitter is directed towards the VS1838 infrared receiver of the counter module and objects are moved between the two modules. Each time an object passes between the two modules, the seven-segment displays show increment in numbers from 0 to 999.
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US $19.95- This is a 74LS192 based up and down counter driver module for driving 2.3″ seven-segment display. The module has headers on two sides to receive up/down count signals and to concatenate with another driver module. You can concatenate unlimited displays.
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The module can be triggered with NE555, flashing LED, and Arduino. It can also be triggered by anything that generates a clock pulse.
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CD4026- 1 Digit Up Counter Module
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US $4.95- It works as an UP counter. You can instantly test the up count of the display using a flashing LED.
- It is a handy tester for 0.56″ seven segments common cathode display.
- Works with Arduino or NE55 or whatever that gives pulse.
- You can concatenate as many displays as you want.
- With this, you can build your own digital objects counter.
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Photoresistor And Laser Operated Large Digital Objects Counter With 2.3″ Displays
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Photoresistor And Laser Operated Large Digital Objects Counter With 2.3″ Displays
US $29.95A laser light module illuminates the photoresistor continuously and whenever any object obstructs the laser light falling on the photoresistor, the counter increases the count. You can use this 3 digit digital objects counter for counting objects or people entering a room. It can be used by engineers for learning about digital counters.
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u did a gr8 job
nice project
nice project….i also did it and it was awesome only i had to look out for a dark place as the ldr sensitivity was a slight of a problem.
About of all components are used in object counter used in LDR and Calculator
i done this project.i realy got good o/p.
What can I use instead of the BD139 Transistor??
You can use any other transistor that can drive the relay.
So something like SL100 or BC 337 would work?
Very good idea and project..i did it as my 3 semester project…but sensitivity is little bit problematic.
i have not found any such caculator which has to work as counter. what can i do to use calculator as counter ?
plz rep asp
how to disable auto power off feature in an electronic calculator because most of the calculators nowadays are electronic….I am hoping for your response…thank you in advance
Can i replace led & ldr with IR light & IR sensor?
You said that in the calculator we have to press “=” sign after pressing 1 then in normal calculator wlif do this thing we didn’t need any circuit,,,,,,,