Arduino Keypad 4x4 Tutorial





Introduction: Arduino Keypad 4x4 Tutorial

Keypad input showed to serial monitor with arduino uno and 4x4 keypad full code...

Step 1: Connecting With Arduino

Connecting keypad with aruduino digital pins:

Keypad Pin Connects to Arduino Pin

1 D9

2 D8

3 D7

4 D6

5 D5

6 D4

7 D3

8 D2

Step 2: Code


#include <Keypad.h>

const byte numRows= 4

const byte numCols= 4;

keymap[numRows][numCols]= { {'1', '2', '3', 'A'},

{'4', '5', '6', 'B'},

{'7', '8', '9', 'C'},

{'*', '0', '#', 'D'} };

byte rowPins[numRows] = {9,8,7,6}; //Rows 0 to 3

byte colPins[numCols]= {5,4,3,2}; //Columns 0 to 3

//initializes an instance of the Keypad class

Keypad myKeypad= Keypad(makeKeymap(keymap), rowPins, colPins, numRows, numCols);

void setup() {



//If key is pressed, this key is stored in 'keypressed' variable //If key is not equal to 'NO_KEY', then this key is printed out //if count=17, then count is reset back to 0 (this means no key is pressed during the whole keypad scan process

void loop() {

char keypressed = myKeypad.getKey();

if (keypressed != NO_KEY)





Step 3:

here is my blogspot link it has some extra diagram which you might find helpfull... blogspot link

Step 4: Adding Library

Adding the library :

To add the library go to Skeetches -->>Include library--> Type the libray name "keypad" then press install.Then upload the sketch to your arduino.
Here's Some optional link :

wordpress blog

Blog spot



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Error message: No such file or directory


What are the materials needed to make that happen thing?

Error message:
" 'keymap' does not name a type"

put "char" (without quotation) in front that line.

Thank You very much...

i tried a lot for connecting the keypad in the above given way but it showed no output in serial monitor, i think this technique does not work

Are you using arduino uno? can you please upload a pic of the connections you made. i guess you misunderstood the pin 8 of your keypad as pin 1 at the very beginning i made that mistake too... i would like to help you out...Thanks

If you wan't to save four arduino pins you can use way: it's only require eight extra cheap diodes.

Thanks :)

This would be a great way to make your own DIY keypad security lock.

Thanks for your query ill upload it soon...stay connected..