I2C slave address for LCD NHD-C0220BIZ-FS(RGB)-FBW-3VM
I am trying to make communication between STM32F4xx and LCD module NHD-C0220BIZ-FS(RGB)-FBW-3VM using I2C protocol.
I am using HAL libraries provided by the ST in this regard and developing in C language.
From the data sheet of the LCD, slave address is given as 0x78.
I am not getting a valid response for the data transfer function call HAL_I2C_Master_Trasmit() from master to slave.
It should return a zero value, while I am getting one value.
In the data sheet on page 6, Fig 5, the slave address is given like 0b01111100, I added 0 at the end because I am writing to the slave.
I tried this address which is 0x7C in HEX.
In one of the arduino codes, the device address is shifted right by 1 bit. 0x78 becomes 0x3C.
I tried all these combinations with no success.
Please update me about this.
Thanks,
-
I have been able to write to this using 0x78, I have attached my code below:
/*************************************************
* Code written to drive NHD-C0220BiZ-FS... Using Arduino Mega.
* Arduino Mega (Voltage Regulator switched with 3.3 V)
**************************************************/
#define SC_L 33
#define SD_A 35
/*****************************************************/
char const text1[]=("COG Test 2x20 Module");
char const text2[]=("TESTING TESTING TEST");
char const text3[]=("Testing Contrast Set");
char const text4[]=("Testing Folower Cont");
/*****************************************************/
/*****************************************************/
const char Slave = 0x78;
const char Comsend = 0x00;
const char Datasend = 0x40;
const char Line2 = 0xC0;
/*****************************************************/
/****************************************************
* Output command or data via I2C *
*****************************************************/
void I2C_out(unsigned char j){ //I2C Output
int n;
unsigned char d;
d=j;
for(n=0;n<8;n++){
if((d&0x80)==0x80)
digitalWrite(SD_A,HIGH);
else
digitalWrite(SD_A,LOW);
d=(d<<1);
digitalWrite(SC_L,LOW);
digitalWrite(SC_L,HIGH);
digitalWrite(SC_L,LOW);
}
digitalWrite(SC_L,HIGH);
while(SD_A==1){
digitalWrite(SC_L,LOW);
digitalWrite(SC_L,HIGH);
}
digitalWrite(SC_L,LOW);
}
/*****************************************************/
/****************************************************
* I2C Start *
*****************************************************/
void I2C_Start(void){
digitalWrite(SC_L,HIGH);
digitalWrite(SD_A,HIGH);
digitalWrite(SD_A,LOW);
digitalWrite(SC_L,LOW);
}
/*****************************************************/
/****************************************************
* I2C Stop *
*****************************************************/
void I2C_Stop(void){
digitalWrite(SD_A,LOW);
digitalWrite(SC_L,LOW);
digitalWrite(SC_L,HIGH);
digitalWrite(SD_A,HIGH);
}
/*****************************************************/
/****************************************************
* Initialization For ST7036i *
*****************************************************/
void init_LCD(){
I2C_Start();
I2C_out(Slave);//Slave=0x78
I2C_out(Comsend);//Comsend = 0x00
I2C_out(0x38);
delay(10);
I2C_out(0x39);
delay(10);
I2C_out(0x14);
I2C_out(0x78);
I2C_out(0x5E);
I2C_out(0x6D);
//I2C_out(0x38);
I2C_out(0x0F);
I2C_out(0x01);
I2C_out(0x06);
delay(10);
I2C_Stop();
}
/*****************************************************
* CONTRAST CONTROL *
/***************************************************/
void contrast(){
/************************************************
* TESTING CONTRAST SET LOWER / Higher Bits *
************************************************/
int n;
I2C_Start();
I2C_out(Slave); //Slave=0x78
I2C_out(Datasend);//Datasend=0x40
for(n=0;n<20;n++){
I2C_out(text1[n]);
//++text;
}
I2C_Stop();
nextline();
I2C_Start();
I2C_out(Slave); //Slave=0x78
I2C_out(Datasend);//Datasend=0x40
for(n=0;n<20;n++){
I2C_out(text3[n]);
//++text;
}
I2C_Stop();
delay(200);
for (int i = 112; i < 128; i++){
I2C_Start();
I2C_out(Slave);
I2C_out(Comsend);
I2C_out(0x39);
delay(10);
I2C_out(i);
I2C_Stop();
delay (300);
}
for (int i = 94; i < 96; i++){
I2C_Start();
I2C_out(Slave);
I2C_out(Comsend);
I2C_out(0x39);
delay(10);
I2C_out(i);
I2C_Stop();
delay (300);
}
init_LCD(); // Return to normal
/************************************************
* TESTING Folower mode
************************************************/
I2C_Start();
I2C_out(Slave); //Slave=0x78
I2C_out(Datasend);//Datasend=0x40
for(n=0;n<20;n++){
I2C_out(text1[n]);
//++text;
}
I2C_Stop();
nextline();
I2C_Start();
I2C_out(Slave); //Slave=0x78
I2C_out(Datasend);//Datasend=0x40
for(n=0;n<20;n++){
I2C_out(text4[n]);
//++text;
}
I2C_Stop();
delay(200);
for (int i = 104; i < 112; i++){
I2C_Start();
I2C_out(Slave);
I2C_out(Comsend);
I2C_out(0x39);
delay(10);
I2C_out(i);
I2C_Stop();
delay (600);
}
init_LCD();
}
/****************************************************
* Send string of ASCII data to LCD *
*****************************************************/
void Show(){
int n;
I2C_Start();
I2C_out(Slave); //Slave=0x78
I2C_out(Datasend);//Datasend=0x40
for(n=0;n<20;n++){
I2C_out(text1[n]);
//++text;
}
I2C_Stop();
nextline();
I2C_Start();
I2C_out(Slave); //Slave=0x78
I2C_out(Datasend);//Datasend=0x40
for(n=0;n<20;n++){
I2C_out(text2[n]);
//++text;
}
I2C_Stop();
}
/*****************************************************/
void nextline(){
I2C_Start();
I2C_out(Slave);
I2C_out(Comsend);
I2C_out(Line2);
I2C_Stop();
}
void setup() {
// put your setup code here, to run once:
//pinMode(pin, mode)
pinMode(33, OUTPUT);
pinMode(35, OUTPUT);
DDRD = 0xFF;
init_LCD();
Show();
delay(300);
}
void loop() {
int i;
init_LCD();
delay(2);
// CONTRAST TESTING
contrast();
delay(1000);
}How does your code send the bits?
0 -
The problem is now solved, the slave address is just 0x78 only.
The problem is that, I need to send each command to the LCD module separately using the function: HAL_I2C_Master_Transmit().
I posted the solution at the following url as a reply to the main post: Please read the complete post to get an understanding of it if u wish.
https://community.st.com/thread/28843
Thanks,0
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