/*****************************************************************************
*
* Program for writing to Newhaven Display's 1x16 Character LCD with the ST7066U Controller.
* This code is written for the Arduino Uno R3 using 4-bit Parallel Interface.
*
* Program Loop:
* 1. Initialize display
* 2. Print "NEWHAVEN DISPLAY".
*
* Newhaven Display invests time and resources providing this open source code,
* Please support Newhaven Display by purchasing products from Newhaven Display!
*
* Copyright (c) 2022, Newhaven Display International
*
* This code is provided as an example only and is not guaranteed by Newhaven Display.
* Newhaven Display accepts no responsibility for any issues resulting from its use.
* The developer of the final application incorporating any parts of this
* sample code is responsible for ensuring its safe and correct operation
* and for any consequences resulting from its use.
*
*****************************************************************************/
/**
* Wiring Reference:
* - Pin 1 VSS - GND
* - Pin 2 VDD - 5.0V
* - Pin 3 V0 - Contrast potentiometer (refer to spec wiring diagram)
* - Pin 4 RS - Arduino D8
* - Pin 5 R/W - Arduino D9
* - Pin 6 E - Arduino D10
* - Pin 7 DB0 - NC
* - Pin 8 DB1 - NC
* - Pin 9 DB2 - NC
* - Pin 10 DB3 - NC
* - Pin 11 DB4 - Arduino D4
* - Pin 12 DB5 - Arduino D5
* - Pin 13 DB6 - Arduino D6
* - Pin 14 DB7 - Arduino D7
* - Pin 15 LED+ - 5.0V
* - Pin 16 LED- - GND
*/
#include
#define E_Pin 10
#define R_W 9
#define R_S 8
char const _text1[] = ("NEWHAVEN");
char const _text2[] = (" DISPLAY");
void setup()
{
initLCD();
disp();
}
void loop()
{
}
/**
* @brief Clear the R/W pin to write data.
*
* @return none
*/
void setWrite()
{
digitalWrite(R_W, LOW); // Write
}
/**
* @brief Clear the RS pin for commands.
*
* @return none
*/
void setCommand()
{
digitalWrite(R_S, LOW); // Command
}
/**
* @brief Set the RS pin for data.
*
* @return none
*/
void setData()
{
digitalWrite(R_S, HIGH); // Data
}
/**
* @brief Toggle enable signal to latch data.
* @return none
*/
void latch()
{
digitalWrite(E_Pin, HIGH);
delay(1);
digitalWrite(E_Pin, LOW);
delay(20);
}
/**
* @brief Send a command byte to the display.
*
* @param command Desired command byte to send.
* @return none
*/
void command(uint8_t command)
{
setCommand();
setWrite();
putByte(command);
}
/**
* @brief Send a data byte to the display.
*
* @param data Desired data byte to send.
* @return none
*/
void data(uint8_t data)
{
setData();
setWrite();
putByte(data);
}
/**
* @brief Clock a byte of data on the 4-bit parallel bus.
*
* @param data Desired data byte to send.
* @return none
*/
void putByte(uint8_t data)
{
putNybble(data);
latch();
data <<= 4;
putNybble(data);
latch();
}
/**
* @brief Put a nybble of data on the 4-bit parallel bus.
*
* @param data Desired data to put on bus.
* @return none
*/
void putNybble(uint8_t data)
{
PORTD = data;
}
/**
* @brief Initialize the connected LCD.
*
* @return none
*/
void initLCD()
{
DDRD = 0xFF; // First 8 pins of PORT D as output
DDRB = 0x07; // Port B first 3 pins as output
digitalWrite(E_Pin, LOW);
delay(100); // Wait >15 msec after power is applied
putNybble(0x30); // Put 30 on port D
delay(30); // must wait 5ms, busy flag not available
latch(); // command 0x30 = Wake up
delay(10); // must wait 160us, busy flag not available
latch(); // command 0x30 = Wake up #2
delay(10); // must wait 160us, busy flag not available
latch(); // command 0x30 = Wake up #3
delay(10); // can check busy flag now instead of delay
putNybble(0x20); // put 0x20 on the output port (NEEDED TO SET 4-bit INTERFACE)
latch();
command(0x28); // Function set: 8-bit/2-line ; NECESSARY due to the DDRAM shift that takes place.
command(0x0F); // Display ON; Blinking cursor
command(0x06); // Entry Mode set
}
/**
* @brief Clear the display.
*
* @return none
*/
void clear_screen()
{
command(0x01);
}
// Return to home position
/**
* @brief Return the cursor to the home position.
*
* @return none
*/
void ret_home()
{
command(0x02);
}
/**
* @brief Write "NEWHAVEN DISPLAY" on the display.
*
* @return none
*/
void disp()
{
clear_screen();
ret_home(); // For 1st 8 characters
for (unsigned int i = 0; i < 8; i++)
{
data(_text1[i]);
}
command(0xC0); // For 2nd 8 characters
for (unsigned int i = 0; i < 8; i++)
{
data(_text2[i]);
}
ret_home();
}
