Introduction

This is a very popular LCD Keypad shield for Arduino or Freeduino board. It includes a 2x16 LCD display and 6 momentary push buttons. Pins 4, 5, 6, 7, 8, 9 and 10 are used to interface with the LCD. Analog Pin 0 is used to read the push buttons. The LCD shield supports contrast adjustment and backlit on/off functions. It also expands analog pins for easy analog sensor reading and display.

The LCD Keypad shield is developed for Arduino compatible boards, 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.

Specification

Board Overview

DFR0009-PIN2.png

Tutorial

Requirements

Function Explanation

LiquidCrystal(rs, enable, d4, d5, d6, d7)

Creates a variable of type LiquidCrystal. The display can be controlled using 4 or 8 data lines. If the former, omit the pin numbers for d0 to d3 and leave those lines unconnected. The RW pin can be tied to ground instead of connected to a pin on the Arduino; if so, omit it from this function's parameters. for example:

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

lcd.begin(cols, rows)

Initializes the interface to the LCD screen, and specifies the dimensions (width and height) of the display. begin() needs to be called before any other LCD library commands.for example:

lcd.begin(16, 2);

lcd.setCursor(col,row)

Set the location at which subsequent text written to the LCD will be displayed. for example:

lcd.setCursor(0,0);

lcd.print(data)

Prints text to the LCD.for example:

lcd.print("hello, world!");

lcd.write(data)

Write a character to the LCD.

More function can see:

Connection Diagram

Plug the LCD Keypad to the UNO(or other controllers)

Temperture sensor: S(blue) -- A1()

Note: A0 has been occupied.

VCC(red) -- VCC

GND(black) -- GND

Tricks for changing sensor cable pin mapping

DFR0009+LM35.png

Sample Code

/*******************************************************

   Description:
   Reads an analog input on pin 1, prints the result to the LCD.
   This program takes the temperture sensor LM35 for example.

   Connection:
   Plug the LCD Keypad to the UNO(or other controllers)
   Temperture sensor:
   S(blue) -- A1()
     Note: A0 has been occupied.
   VCC(red) -- VCC
   GND(black) -- GND

********************************************************/

#include <LiquidCrystal.h>

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);        // select the pins used on the LCD panel

unsigned long tepTimer ;

void setup(){
    lcd.begin(16, 2);                       // start the library
}

void loop(){
    lcd.setCursor(0, 0);                   // set the LCD cursor   position
    int val;                               // variable to store the value coming from the analog pin
    double data;                           // variable to store the temperature value coming from the conversion formula
    val=analogRead(1);                     // read the analog in value:
    data = (double) val * (5/10.24);       // temperature conversion formula

    if(millis() - tepTimer > 500){         // output a temperature value per 500ms
             tepTimer = millis();

             // print the results to the lcd
             lcd.print("T: ");
             lcd.print(data);
             lcd.print("C");
     }
}

Expected Results

DFR0009+TEM.jpg

FAQ

Q&A Some general Arduino Problems/FAQ/Tips
Q1 I do not understand your schematic. There are too many connectors illustrated than are actually on the shield. Could you show me a mapping?
A1 The J1-J8 include the both the user interface, i.e. Analog pins, APC220(Serial) pins, Digital pins, and the pins connected with the lower Arduino card, e.g. Uno/ Leonardo. Here is a simple mapping picture.
Q2 Why my LCD keypad cannot display anything on the Intel Edison while all right on Romeo?
A2 It works well if uploaded by Arduino 1.5.3 version, however, the latest 1.6.* have discard pin Definition for Edison. So you have to add pinMode(); into the setup() like this:
void setup() {
  for(int i=4;i<10;i++){
  pinMode(i,OUTPUT);
  }
  lcd.begin(16, 2);  // set up the LCD's number of columns and rows
}

For A2. Pin mapping on schematic

Q&A Some general Arduino Problems/FAQ/Tips
A For any questions, advice or cool ideas to share, please visit the DFRobot Forum.

More Documents

DFshopping_car1.png Get Gravity: 1602 LCD Keypad Shield For Arduino from DFRobot Store or DFRobot Distributor.

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