Ads by ArduinoGetStarted.com
Arduino - Keypad - LCD
Hardware Required
Or you can buy the following sensor kits:
| 1 | × | DIYables Sensor Kit (30 sensors/displays) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
Disclosure: Some links in this section are Amazon affiliate links. If you make a purchase through these links, we may earn a commission at no extra cost to you.
Additionally, some links direct to products from our own brand, DIYables.
Additionally, some links direct to products from our own brand, DIYables.
About Keypad and LCD
If you do not know about keypad and LCD (pinout, how it works, how to program ...), learn about them in the following tutorials:
Wiring Diagram
This image is created using Fritzing. Click to enlarge image
Arduino Code
/*
* Created by ArduinoGetStarted.com
*
* This example code is in the public domain
*
* Tutorial page: https://arduinogetstarted.com/tutorials/arduino-keypad-lcd
*/
#include <Keypad.h>
#include <LiquidCrystal_I2C.h>
const int ROW_NUM = 4; // four rows
const int COLUMN_NUM = 4; // four columns
char keys[ROW_NUM][COLUMN_NUM] = {
{'1','2','3', 'A'},
{'4','5','6', 'B'},
{'7','8','9', 'C'},
{'*','0','#', 'D'}
};
byte pin_rows[ROW_NUM] = {9, 8, 7, 6}; // connect to the row pinouts of the keypad
byte pin_column[COLUMN_NUM] = {5, 4, 3, 2}; // connect to the column pinouts of the keypad
Keypad keypad = Keypad(makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM );
LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27, 16 column and 2 rows
int cursorColumn = 0;
void setup(){
lcd.init(); // initialize the lcd
lcd.backlight();
}
void loop(){
char key = keypad.getKey();
if (key) {
lcd.setCursor(cursorColumn, 0); // move cursor to (cursorColumn, 0)
lcd.print(key); // print key at (cursorColumn, 0)
cursorColumn++; // move cursor to next position
if(cursorColumn == 16) { // if reaching limit, clear LCD
lcd.clear();
cursorColumn = 0;
}
}
}
※ NOTE THAT:
The I2C address of LCD can vary according to the manufacturers. In the code, we used 0x27 that is specified by DIYables manufacturer
Quick Steps
- Connect Arduino to PC via USB cable
- Open Arduino IDE, select the right board and port
- Navigate to the Libraries icon on the left bar of the Arduino IDE.
- Search “keypad”, then find the keypad library by Mark Stanley, Alexander Brevig
- Click Install button to install keypad library.
- Search “LiquidCrystal I2C”, then find the LiquidCrystal_I2C library by Frank de Brabander
- Click Install button to install LiquidCrystal_I2C library.
- Copy the above code and open with Arduino IDE
- Click Upload button on Arduino IDE to upload code to Arduino
- Press some keys on keypad
- See the result in LCD
If LCD displays nothing, see Troubleshooting on LCD I2C
Code Explanation
Read the line-by-line explanation in comment lines of source code!
Video Tutorial
We are considering to make the video tutorials. If you think the video tutorials are essential, please subscribe to our YouTube channel to give us motivation for making the videos.