Basic LCD Control- Arduino Workshop
we will create a demonstration project Arduino Basic LCD Control that will show off most of the functions available in the LiquidCrystal.h library. We will be using a backlit 16x2 LCD Display. You will need to obtain an LCD display that uses the HD44780 driver. There are many available, and they come in all kinds of colors. As an amateur astronomer, I particularly like the red-on-black displays as they preserve your night vision. These have red text on a black background. You can, of course, choose any available color text and background you wish. Your display must have a backlight and be able to display sixteen columns and two rows of characters. These are often referred to as 16x2 LCD displaysRequired Component :
1.Arduino
2. Resistors
6. Breadboard
Circuit diagram Basic LCD Control:
Data pins 0 to 3 are not used, as we are going to use what is known as 4-bit mode, The contract adjustment pin on the LCD must be connected via a current-limiting resistor to adjust the contrast to the desired level. A value of around 10KΩ should suffice. If you find it difficult to get the right value, then connect a potentiometer with a value between about 4KΩ to 10KΩ with the left leg to +5V, the right leg to the ground, and the center leg to the contrast adjustment pin (pin 3 on my LCD).
This way, you can use the knob to adjust the contrast until you can see the display clearly. The backlight on the LCD I used required 4.2V, so I added the appropriate current-limiting resistor between +5V and the LED power supply pin (pin 15 in my LCD). You could, of course, connect the LED power pin to a PWM pin (via a current-limiting resistor) on the Arduino and use a PWM output to control the brightness of the backlight.
For simplicity’s sake, we will not use that method in this project. Once you are happy that your circuit matches mine with the correct pins going between the Arduino, +5V, and ground (according to the LCDs datasheet), then you can enter the code
Code Basic LCD Control
#include <LiquidCrystal.h>
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2); // create an lcd object and
assign the pins
void setup() {
lcd.begin(16, 2); // Set the display to 16
columns and 2 rows
}
void loop() {
// run the 7 demo routines
basicPrintDemo();
displayOnOffDemo();
setCursorDemo();
scrollLeftDemo();
scrollRightDemo();
cursorDemo();
createGlyphDemo();
}
void basicPrintDemo() {
lcd.clear(); // Clear the display
lcd.print("Basic Print"); // print some text
delay(2000);
}
void displayOnOffDemo() {
lcd.clear(); // Clear the display
lcd.print("Display On/Off"); // print some text
for(int x=0; x < 3; x++) { // loop 3 times
lcd.noDisplay(); // turn display off
delay(1000);
lcd.display(); // turn it back on again
delay(1000);
}
}
void setCursorDemo() {
lcd.clear(); // Clear the display
lcd.print("SetCursor Demo"); // print some text
delay(1000);
lcd.clear(); // Clear the display
lcd.setCursor(5,0); // cursor at column 5 row 0
lcd.print("5,0");
delay(2000);
lcd.setCursor(10,1); // cursor at column 10 row
1
lcd.print("10,1");
delay(2000);
lcd.setCursor(3,1); // cursor at column 3 row 1
lcd.print("3,1");
delay(2000);
}
void scrollLeftDemo() {
lcd.clear(); // Clear the display
lcd.print("Scroll Left Demo");
delay(1000);
lcd.clear(); // Clear the display
lcd.setCursor(7,0);
lcd.print("Beginning");
lcd.setCursor(9,1);
lcd.print("Arduino");
delay(1000);
for(int x=0; x<16; x++) {
lcd.scrollDisplayLeft(); // scroll display left 16
times
delay(250);
}
}
void scrollRightDemo() {
lcd.clear(); // Clear the display
lcd.print("Scroll Right");
lcd.setCursor(0,1);
lcd.print("Demo");
delay(1000);
lcd.clear(); // Clear the display
lcd.print("Beginning");
lcd.setCursor(0,1);
lcd.print("Arduino");
delay(1000);
for(int x=0; x<16; x++) {
lcd.scrollDisplayRight(); // scroll display right 16
times
delay(250);
}
}
void cursorDemo() {
lcd.clear(); // Clear the display
lcd.cursor(); // Enable cursor visible
lcd.print("Cursor On");
delay(3000);
lcd.clear(); // Clear the display
lcd.noCursor(); // cursor invisible
lcd.print("Cursor Off");
delay(3000);
lcd.clear(); // Clear the display
lcd.cursor(); // cursor visible
lcd.blink(); // cursor blinking
lcd.print("Cursor Blink On");
delay(3000);
lcd.noCursor(); // cursor invisible
lcd.noBlink(); // blink off
}
void createGlyphDemo() {
lcd.clear();
byte happy[8] = { // create byte array with happy
face
B00000,
B00000,
B10001,
B00000,
B10001,
B01110,
B00000,
B00000};
byte sad[8] = { // create byte array with sad
face
B00000,
B00000,
B10001,
B00000,
B01110,
B10001,
B00000,
B00000};
lcd.createChar(0, happy); // create custom character 0
lcd.createChar(1, sad); // create custom character 1
for(int x=0; x<5; x++) { // loop animation 5 times
lcd.setCursor(8,0);
lcd.write((byte)0); // write custom char 0
delay(1000);
lcd.setCursor(8,0);
lcd.write(1); // write custom char 1
delay(1000);
}
}
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