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Character LCDs / NHD-0420D3Z-NSW-BBW-V3 i2c display and Arduino missing characters
« on: July 06, 2017, 11:05:59 AM »
For some reason my i2c display appears to be missing random characters. I've adjusted the i2c speed and delays but characters are still missing. It's connected to a new Arduino UNO. I'm not sure if the Uno has built in pull-up resistors on the SDA & SCL lines but the display has onboard 10K pull-ups.
On the screen now I see:
124679
BCEGHJLMOQRT
and my code is:
[attachment deleted by admin]
On the screen now I see:
124679
BCEGHJLMOQRT
and my code is:
Code: [Select]
/*
Newhaven NHD-0420D3Z-NSW-BBW-V3 LCD
R1 shorted with a 0R resistor
SCL and SDA pullup resistors already on LCD
*/
#include <Wire.h>
#define I2C_ADDRESS 0x28 //LCD I2C address 0x28??? It should be 0x50
#define DISPLAY_ON 0x41 //DISPLAY ON
#define DISPLAY_OFF 0x42 //DISPLAY OFF
#define SET_CURSOR 0x45 //SET CURSOR
#define CURSOR_HOME 0x46 //CURSOR HOME
#define MOVE_CURSOR_LEFT 0x49 //MOVE CURSOR LEFT
#define MOVE_CURSOR_RIGHT 0x4A //MOVE CURSOR RIGHT
#define BLINK_CURSOR_ON 0x4B //BLINK CURSOR ON
#define BLINK_CURSOR_OFF 0x4C //BLINK CURSOR OFF
#define BACKSPACE 0x4E //BACKSPACE
#define CLEAR_SCREEN 0x51 //CLEAR SCREEN
#define SET_CONTRAST 0x52 //SET CONTRAST
#define SET_BACKLIGHT 0x53 //SET BACKLIGHT
#define MOVE_DISP_LEFT 0x55 //MOVE DISPLAY LEFT
#define MOVE_DISP_RIGHT 0x56 //MOVE DISPLAY RIGHT
#define DISP_I2C_ADDR 0x72 //DISPLAY I2C ADDRESS
void setup()
{
Wire.setClock(100000); //sets I2C speed to 100kHz
Wire.begin();
Serial.begin(9600);
delay(1000);
Display_Clear();
//Cursor_Home();
Set_Cursor_Line_1();
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(0xFE); //Prefix
Wire.write("0123456789"); //Display Text
Wire.endTransmission();
Set_Cursor_Line_2();
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(0xFE); //Prefix
Wire.write("ABCDEFGHIJKLMNOPQRST"); //Display Text
Wire.endTransmission();
delay(1000); //wait for a second
}
void loop()
{
}
void Display_On(void)
{
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(0xFE); //Prefix
Wire.write(DISPLAY_ON); //Display On
Wire.endTransmission();
delay(2); //wait for a 1/4 second
}
void Display_Clear(void)
{
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(0xFE); //Prefix
Wire.write(CLEAR_SCREEN); //Clear Display
Wire.endTransmission();
delay(2); //wait for a 1/4 second
}
void Set_Cursor_Line_1(void)
{
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(0xFE); //Prefix
Wire.write(0x45); //Set Cursor
Wire.write(0x00); //
Wire.endTransmission();
delay(2); //wait for a 1/4 second
}
void Set_Cursor_Line_2(void)
{
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(0xFE); //Prefix
Wire.write(0x45); //Set Cursor
Wire.write(0x40); //
Wire.endTransmission();
delay(2); //wait for a 1/4 second
}
void Cursor_Home(void)
{
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(0xFE); //Prefix
Wire.write(CURSOR_HOME); //Cursor Home
Wire.endTransmission();
delay(2); //wait for a 1/4 second
}
void Cursor_Right(void)
{
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(0xFE); //Prefix
Wire.write(MOVE_CURSOR_RIGHT); //Cursor Home
Wire.endTransmission();
delay(2); //wait for a 1/4 second
}
[attachment deleted by admin]