Arduino Coin Selector with LCD display

Hello everyone,

I am fairly new to Arduino and trying to build a vending machine with an LCD and a coin selector.

I set up the coin selector with three types of coins, us nickel, dime, and quarters (pulse 5, 10, 25). However, when I ran the program, the LCD would show an amount of 3.6 dollars received only with a quarter inserted.

I am very confused that how does arduino read the actual value of the coin?

Thank you very much in advance!

when I ran the program

What program would that be ?

Stefanie, more input! We aren't psychic and neither is your Arduino. You need to tell it the value of each coin from your coin selector.

In addition to your code, it would help to know which coin acceptor you are using, and exactly how it is connected to the arduino. From your post, it sounds as if the coin acceptor outputs pulses to indicate the coin denomination, depending on how that is done you may have to debounce the input.