Arduino coin Counting Machine Question

Greetings Utku,

I assume by ldr you mean Light Dependent Resistors?

You could utilize a light on those LDR devices and count how many times the light goes out.  When an LDR detects light its resistance drops.  Going into the input of an Arduino or similar will be able to count the times the voltage drops (or goes high depending on your circuit).  The chamber for each coin, however, would have to be designed such that the only light the LDR sees is completely blocked by the coin falling past.  For an alternative, I would utilize a photo-transistor instead of an LDR.  You can set them up to be a bit more sensitive to the change in light thereby giving you a better resolution in your voltage change.  Still, though, you need to make sure the light source is focused and coin falling past blocks it out as completely as possible.

I hope this helps!  If you need anything else, please ask away.  Send a schematic as well so I can be on the same page with you!

Personally I would use a photo-transistor to detect the coins dropping.

This would effectively give you a pulse (input pin going LOW) when the coin passes.

You'll find it a little faster and easier than using LDRs.

For some gaming machines, the coin detectors use a sample coin and compare the electronic signal of the sample and the inserted coin.

A deflector lower down either deflects it into the hopper, or it drops right through and out the reject/return chute.

This avoids the problem of similar sized objects being accepted instead of the correct coin.

Mark

Sorry for giving a reply after couple of months. First of all, Thank you. I cancelled thee project anyways. Maybe I'll do it in the future. Again, thanks for the advice.