Hi , I look for helping about Coin sensor , I will make a piggy bank.
But I don't know how to detecting a coin.
I want to read a value of the coin only.
Someone suggest me to use Photo Interrupter.
Could you suggest me how to use Photo Interrupter to be a Coin Sensor?

Thank you.

 

Hello,

A photo interupter will not tell you the value of the coin.
It can only tell you how many coins have passed.

Bertus

 

Research some of the methods used in existing commercial models.

http://www.nri.de/en_153_1.html
http://content.honeywell.com/sensing/solutions/markets/infotech/application/006463_2.pdf

 

There are a couple of methods. I've done one which will only really tell the difference between 2 coin types and only if they are quite different sizes. It works well for UK 1p and 2p coins for example. The coins roll down a ramp from a position where they are stationary at the top. The photointerrupter further down the ramp times how long they block the sensor so a short time is the smaller coin.

The other method is to have as many sensors as there are sizes of coins and have them in a line down the ramp so that the top of each size of coin blocks at least one sensor.