Newhaven Display Forum

Hi I am using the Newhaven NHD-0216S3Z-FL-GBW-V3 16x2 Character display
using an Arduino Leonardo, with I2C communication

For this display it is important to set the Arduino's I2C communication speed to 100Khz

One way to do this is with the following statement, in void setup():

   TWBR = 100000; //sets I2C spaeed to 100kHz very important

The NHD-0216S3Z-FL-GBW-V3 manual states the default I2C address is 0x50, but it was actually 0x28

This code works for the NHD-0216S3Z-FL-GBW-V3 on the I2C bus:

// ----------------------------------------------------------------
#include <Wire.h> //I2C library
const byte LCDa = 0x28; //LCD address on I2C bus

void setup()  {
   TWBR = 100000; //sets I2C speed to 100kHz very important
   
        LCDclear();
        delay(500);     // for observation only can be removed
         
        LCDline1col1(); // position cursor Line #1, col#1
       
        Wire.beginTransmission(LCDa); // Write to LCD Line #1, col#1             
        Wire.write("Hello World 2017");     
        Wire.endTransmission();
     
         LCDline2col1(); // position cursor Line #2, col#1
               
        Wire.beginTransmission(LCDa); // Write to LCD Line #2, col#1               
        Wire.write("Welcome Home eh?");             
        Wire.endTransmission();

  }

void loop()
  { 
  }

  // Clear the NHD Extended LCD Screen
void LCDclear() {
  Wire.beginTransmission(LCDa);
  Wire.write (0xFE);
  Wire.write(0x51);
  Wire.endTransmission();
  delay(2);
}

  // Set Cursor to Line #1, Col #1 NHD Extended LCD Screen
void LCDline1col1() {
  Wire.beginTransmission(LCDa);
  Wire.write (0xFE);
  Wire.write(0x45);
  Wire.write(0x00);   
  Wire.endTransmission();
  delay(2);
}

  // Set Cursor to Line #2, Col #1 NHD Extended LCD Screen
void LCDline2col1() {
  Wire.beginTransmission(LCDa);
  Wire.write (0xFE);
  Wire.write(0x45);
  Wire.write(0x40);   
  Wire.endTransmission();
  delay(2);
}


Scanner code to read all I2C devices attaced that worked for me is:

/*****************************************************
 * name:I2C_Address
 * function:read the address's of the I2C devices
 * Connection:
 * I2C                 Leonardo
 * GND                 GND
 * VCC                  5V
 * SDA                  2 Leonardo (UNO A4) (pin20 in mega2560)
 * SCL                  3 Leonardo (UNO A5) (pin21 in mega2560)
 ********************************************************/

#include <Wire.h>

void setup()
{

  TWBR = 100000; //sets I2C spaeed to 100kHz very important
 
  Wire.begin();
  Serial.begin(9600);
  Serial.println("\nI2C Scanner");
}
void loop()
{
  byte error, address;
  int nDevices;
  Serial.println("Scanning...");
  nDevices = 0;
  for(address = 1; address < 127; address++ )
  {
    // The i2c_scanner uses the return value of
    // the Write.endTransmisstion to see if
    // a device did acknowledge to the address.
    Wire.beginTransmission(address);
    error = Wire.endTransmission();
    if (error == 0)
    {
      Serial.print("I2C device found at address 0x");
      if (address<16)
        Serial.print("0");
      Serial.print(address,HEX);
      Serial.println(" !");
      nDevices++;
    }
    else if (error==4)
    {
      Serial.print("Unknow error at address 0x");
      if (address<16)
        Serial.print("0");
      Serial.println(address,HEX);
    }
  }
  if (nDevices == 0)
    Serial.println("No I2C devices found\n");
  else
    Serial.println("done\n");
  delay(5000); // wait 5 seconds for next scan
}

Newhaven should publish better Arduino Code examples, and reminding people that the manual states 100Khz max,

I spent several hours on this before I found this on the Arduino Forum

  TWBR = 100000; //sets I2C speed to 100kHz very important