Arduino Nano - Keypad - LCD
This tutorial instructs you how to use Arduino Nano to display the input from keypad on LCD display.
Hardware Preparation
Or you can buy the following sensor kits:
| 1 | × | DIYables Sensor Kit (30 sensors/displays) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
Disclosure: Some of the links provided in this section are Amazon affiliate links. We may receive a commission for any purchases made through these links at no additional cost to you.
Additionally, some of these links are for products from our own brand, DIYables.
Additionally, some of these links are for products from our own brand, DIYables.
Overview of Keypad and LCD
If you are unfamiliar with keypad and LCD (pinout, how it works, how to program ...), the following tutorials can help you:
Wiring Diagram
This image is created using Fritzing. Click to enlarge image
Arduino Nano Code
/*
* This Arduino Nano code was developed by newbiely.com
*
* This Arduino Nano code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-nano/arduino-nano-keypad-lcd
*/
#include <Keypad.h>
#include <LiquidCrystal_I2C.h>
const int ROW_NUM = 4; //four rows
const int COLUMN_NUM = 3; //four columns
const byte pin_rows[ROW_NUM] = {10, 9, 8, 7}; // The Arduino Nano pin connected to the row pins of the keypad
const byte pin_column[COLUMN_NUM] = {6, 5, 4}; // The Arduino Nano pin connected to the column pins of the keypad
char key_layout[ROW_NUM][COLUMN_NUM] = {
{'1', '2', '3'},
{'4', '5', '6'},
{'7', '8', '9'},
{'*', '0', '#'}
};
Keypad keypad = Keypad( makeKeymap(key_layout), pin_rows, pin_column, ROW_NUM, COLUMN_NUM);
LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27 (from DIYables LCD), 16 column and 2 rows
int cursorColumn = 0;
void setup() {
lcd.init(); // Initialize the LCD I2C display
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 address of the LCD may differ depending on the manufacturer. In our code, we have used 0x27, as specified by DIYables.
Detailed Instructions
- Connect an USB cable to the Arduino Nano and the PC.
- Open the Arduino IDE, select the appropriate board and port.
- Click to the Libraries icon on the left bar of the Arduino IDE.
- Search for “keypad” and locate the keypad library by Mark Stanley and Alexander Brevig.
- Press the Install button to install the keypad library.
- Search for “LiquidCrystal I2C” and locate the LiquidCrystal_I2C library created by Frank de Brabander.
- Then, click the Install button to install the said library.
- Copy the code and open it in Arduino IDE.
- Click the Upload button on Arduino IDE to compile and upload the code to Arduino Nano.
- Press certain keys on the keypad
- Check out the outcome on the LCD display
If the LCD does not show anything, . check out Troubleshooting on LCD I2C for help.
Code Explanation
Check out the line-by-line explanation contained in the comments of the source code!