1602 LCD Keypad Shield Test
The 1602 LCD Keypad Shield is an expensive and easy way to add a simple 16 x 2 LCD screen and 5 button menu to your Arduino projects.
The LCD Display uses the LiquidCrystal library that comes standard with the Arduino IDE. The library examples work with the following change in the initialization:
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
The 5 navigation buttons use a resistor ladder to connect to analog pin 0. Just use the analogRead(); command to read in the different values.
You may use the following modified example code at the right to test out your shield.
The number shows the value that the analog pin last received. The button name is displayed on the second row. Because the numbers read in on analog pin 0 can vary slightly, a range of values is used for each button.
/*
1602 LCD Keypad Shield Example Code using the LiquidCrystal Library
Library originally added 18 Apr 2008 by David A. Mellis
library modified 5 Jul 2009 by Limor Fried
example added 9 Jul 2009
by Tom Igoe
modified 22 Nov 2010
by Tom Igoe
modified Jan 2013 for the 1602 LCD Keypad Shield
by Bentley Born
This example code is in the public domain.
http://arduino.cc/en/Tutorial/LiquidCrystalDisplay
*/
// include the library code:
#include <LiquidCrystal.h>
int x = 0;
int currx = 1023;
String btnStr = "None";
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// Print a message to the LCD.
lcd.clear();
lcd.setCursor(0,0);
lcd.print("Analog 0: ");
lcd.print(currx);
lcd.setCursor(0,1);
lcd.print(btnStr);
}
void loop() {
x = analogRead(A0); // the buttons are read from the analog0 pin
// Check if x has changed
if ((x != 1023) && (x != currx)){
//update screen and change currx
lcd.setCursor(10,0);
lcd.print(" ");
lcd.setCursor(10,0);
lcd.print(x);
currx = x;
if (currx > 740 && currx < 745){
btnStr="Select";
} else if (currx > 500 && currx < 510){
btnStr="Left";
} else if (currx < 10){
btnStr="Right";
} else if (currx > 140 && currx < 150){
btnStr="Up";
} else if (currx > 320 && currx < 365){
btnStr="Down";
}
//update button pressed
lcd.setCursor(0,1);
lcd.print(" ");
lcd.setCursor(0,1);
lcd.print(btnStr);
}
delay(10);
}