LCD Keypad

HostChoice.net: LCD Keypad
Posted in: code | by HostChoice.net | 2017 Oct 08


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The original code was found on

but there were a lot of errors in the format.

After working out most of the bugs, this version is able to handle as many relays as there are digital i/o pins.

Note: I just thought of a marketable product based on this. A backup replacement for broken turn signal on vehicles. We need a turn left, turn right, stop, flash, alternate flash.

Thanks!

// code lcdkeypad
/*
digitalWrite(pinLED, HIGH);
*/

//Sample using LiquidCrystal library
 #include <LiquidCrystal.h>

/****************************************
 This program will test the LCD panel and
 the buttons Mark Bramwell, July 2010

https://www.dfrobot.com/wiki/index.php/Arduino_LCD_KeyPad_Shield_(SKU:_DFR0009)
 *****************************************/

// 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

// depending on which button was pushed, we perform an action

switch (lcd_key)
 {
 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;
 }
 }
 }

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