## Introduction [![Arduino LCD KeyPad Shield (SKU: DFR0009)](https://raw.githubusercontent.com/DFRobot/DFRobotMediaWikiImage/master/Image/LCD&KeyPad_Shield.jpg)](https://www.dfrobot.com/product-51.html) The [**arduino *LCD Keypad shield***](https://www.dfrobot.com/product-51.html) is developed for [**Arduino compatible boards**](https://www.dfrobot.com/category-104.html), to provide a user-friendly interface that allows users to go through the menu, make selections etc. It consists of a 1602 white character blue backlight LCD. The keypad consists of 5 keys — select, up, right, down and left. To save the digital IO pins, the keypad interface uses only one ADC channel. The key value is read through a 5 stage voltage divider. Note: Version 1.1 main updates are the button values, which have being updated on the example code. For older version check the comments and edit, or use the Enhanced V1.0 library. ### Board Diagram ![LCD\&Keypad Shield Diagram](https://raw.githubusercontent.com/DFRobot/DFRobotMediaWikiImage/master/Image/Arduino_Shield8.png "LCD&Keypad Shield Diagram") ![Pin Out Diagram](https://raw.githubusercontent.com/DFRobot/DFRobotMediaWikiImage/master/Image/LCD_Shield.png "Pin Out Diagram") ### Pin Allocation | Pin | Function | | ---------- | ----------------------------------------- | | Analog 0 | Button (select, up, right, down and left) | | Digital 4 | DB4 | | Digital 5 | DB5 | | Digital 6 | DB6 | | Digital 7 | DB7 | | Digital 8 | RS (Data or Signal Display Selection) | | Digital 9 | Enable | | Digital 10 | Backlit Control | ### Sample Code #### Example use of LiquidCrystal library //Sample using LiquidCrystal library #include /******************************************************* This program will test the LCD panel and the buttons Mark Bramwell, July 2010 ********************************************************/ // select the pins used on the LCD panel LiquidCrystal lcd(8, 9, 4, 5, 6, 7); // define some values used by the panel and buttons int lcd_key = 0; int adc_key_in = 0; #define btnRIGHT 0 #define btnUP 1 #define btnDOWN 2 #define btnLEFT 3 #define btnSELECT 4 #define btnNONE 5 // read the buttons int read_LCD_buttons() { adc_key_in = analogRead(0); // read the value from the sensor // my buttons when read are centered at these valies: 0, 144, 329, 504, 741 // we add approx 50 to those values and check to see if we are close if (adc_key_in > 1000) return btnNONE; // We make this the 1st option for speed reasons since it will be the most likely result // For V1.1 us this threshold if (adc_key_in < 50) return btnRIGHT; if (adc_key_in < 250) return btnUP; if (adc_key_in < 450) return btnDOWN; if (adc_key_in < 650) return btnLEFT; if (adc_key_in < 850) return btnSELECT; // For V1.0 comment the other threshold and use the one below: /* if (adc_key_in < 50) return btnRIGHT; if (adc_key_in < 195) return btnUP; if (adc_key_in < 380) return btnDOWN; if (adc_key_in < 555) return btnLEFT; if (adc_key_in < 790) return btnSELECT; */ return btnNONE; // when all others fail, return this... } void setup() { lcd.begin(16, 2); // start the library lcd.setCursor(0,0); lcd.print("Push the buttons"); // print a simple message } void loop() { lcd.setCursor(9,1); // move cursor to second line "1" and 9 spaces over lcd.print(millis()/1000); // display seconds elapsed since power-up lcd.setCursor(0,1); // move to the begining of the second line lcd_key = read_LCD_buttons(); // read the buttons switch (lcd_key) // depending on which button was pushed, we perform an action { case btnRIGHT: { lcd.print("RIGHT "); break; } case btnLEFT: { lcd.print("LEFT "); break; } case btnUP: { lcd.print("UP "); break; } case btnDOWN: { lcd.print("DOWN "); break; } case btnSELECT: { lcd.print("SELECT"); break; } case btnNONE: { lcd.print("NONE "); break; } } } #### Example use of Enhanced LiquidCrystal_I2C library(Not updated) This library inherits LiquidCrystal and adds another method: button - to read button pushed on a keypad. This works on the Old version of the board V1.0 [Library Forum](https://www.dfrobot.com/forum/index.php?topic=31.0) ``` /* DFRobot LCD Shield for Arduino Key Grab v0.2 Written by Glendon Klassen gjklassen@gmail.com http://www.sourceforge.net/users/ecefixer http://ecefixer.tumblr.com Displays the currently pressed key on the LCD screen. Key Codes (in left-to-right order): None - 0 Select - 1 Left - 2 Up - 3 Down - 4 Right - 5 */ #include #include //Pin assignments for DFRobot LCD Keypad Shield LiquidCrystal lcd(8, 9, 4, 5, 6, 7); //--------------------------------------------- DFR_Key keypad; int localKey = 0; String keyString = ""; void setup() { lcd.begin(16, 2); lcd.clear(); lcd.setCursor(0, 0); lcd.print("Key Grab v0.2"); delay(2500); /* OPTIONAL keypad.setRate(x); Sets the sample rate at once every x milliseconds. Default: 10ms */ keypad.setRate(10); } void loop() { /* keypad.getKey(); Grabs the current key. Returns a non-zero integer corresponding to the pressed key, OR Returns 0 for no keys pressed, OR Returns -1 (sample wait) when no key is available to be sampled. */ localKey = keypad.getKey(); if (localKey != SAMPLE_WAIT) { lcd.clear(); lcd.setCursor(0, 0); lcd.print("Current Key:"); lcd.setCursor(0, 1); lcd.print(localKey); } } ``` ## More Documents - [LCDKeypad Shield Schematics V1.0](https://www.dfrobot.com/image/data/DFR0009/LCDKeypad%20Shield%20V1.0%20SCH.pdf) - [Shield diagram](http://www.shieldlist.org/dfrobot/lcd) Old libraries for V1: - [LCDKeypad](https://www.dfrobot.com/image/data/DFR0009/LCDKeypad.zip) - [DFR_Key](https://www.dfrobot.com/image/data/DFR0009/DFR_Key.zip)

Arduino LCD KeyPad Shield SKU DFR0009