Object Counter Circuit

Thread Starter


Joined Feb 10, 2007
i need a circuit which counts the number of objects passing over it and simultaneously display the counted objects , does any one know a circuit or what is reqd to construct this circuit pls reply................thanx in advance


Joined Apr 2, 2007
by display of counted objects do you mean displaying the objects(this i think will be super-hard) or the count?
for counting use of ir sensors placed above ir source seems a good approach.


Joined Jul 17, 2007
You could use a photoresistor tied to Vcc in series to ground with a fixed resistor to generate a count pulse. You'd get the pulse from the junction between the two. You might need to use a comparator to square up the pulse to avoid false triggering.

Then to make it really easy, use CMOS 4026 or 4033 IC's to drive your 7-segment LED display. If you need to count higher than 9 objects, just cascade more 4026's or 4033's to drive your additional 7-seg LED's. If you need to count more than around 9,999 objects, you might start thinking about a different approach, like multiplexing and using separate counters/display drivers.
What's the 555 and transistor for? the TSOP1738 has a buffered output all you may require is a pullup resistor. Can't you cleanup the sensor data in software? What is 47E (I assume ohms) and the value for R13 is missing. You'll also need 22pf caps on the crystal or it may not start and decoupling caps near the ICs will help otherwise it'll probably reboot when it switches the displays on & off.

Note: you'll need a 38KHz modulated IR source for the circuit to work properly.