How to use membrane matrix keypad??

Hi guys! I'm a newbie in using arduino and I have a school experiment about it. I have to use a "membrane matrix keypad" and two led lights (1 red and 1 green). If the password typed on the keypad is correct, the green light will turn on but if the password is incorrect, the red light will turn on. I don't have an idea how to use the keypad and its program that's why i can't finish the experiment. I need help from you guys as soon as possible. Thank you!! :expressionless:

Without your code and accurate descriptions of your hardware, it is going to be hard to help you.

Dmitri0004:
Hi guys! I'm a newbie in using arduino and I have a school experiment about it.

We can't do your homework for you, only give clues. What have you done so far?

The way membrance keypad works is to short two contacts, one belongs to "row" and one belongs to "column". Most of the time you need to "scan" the matrix by, for example, making row to be output and columns to be input. Set only one row to logic high and read columns (pulled down by resistors), and then next row, and so on.

If row 1 is logic high (other rows to low) and column 2 of row 1 is pressed, the column 2 reading will be high, so you know row 1 column 2 button is pressed.

Of course, you need to debounce all buttons so that you do not get false readings.

Like many said, we are not here to do your homework, so go and have fun now :slight_smile:

There are several ways to do this.

Type "Arduino Keypad" into Google, to see how to do it. :wink: