Learning STM32 + LCD Interfacing code not working

[thannara123]

Hello
I am trying to interface 4 bit LCD (16x2 ) with STM32f103 controller its not working whats the wrong with me .The main.c code is attached here with


LCD.C file

#include "lcd.h"
#include "main.h"



extern void Delay_Us (uint16_t us);
void LCD_Strobe(void)
{

  HAL_GPIO_WritePin(GPIOB,GPIO_PIN_11, GPIO_PIN_SET);// LCD Enable PIN to High
  HAL_Delay(1);
  //Delay_Us(100);
  HAL_GPIO_WritePin(GPIOB,GPIO_PIN_11, GPIO_PIN_RESET);// LCD Enable High to Low
  //Delay_Us(100);
  HAL_Delay(1);
 }


void LCD_init(void)
{

  HAL_Delay(40);
  LCD_cmd(0x28);
  HAL_Delay(1);
  LCD_cmd(0x28);
  HAL_Delay(1);
  //Delay_Us(100);
  LCD_cmd(0x28);
  LCD_cmd(0x28);            // Function set (4-bit interface, 2 lines, 5*7Pixels)
  LCD_cmd(0x28);            // Function set (4-bit interface, 2 lines, 5*7Pixels)
//  LCD_cmd(0x0c);            // Make cursorinvisible
//    LCD_Clear();            // Clear screen
 //  LCD_cmd(0x6);            // Set entry Mode(auto increment of cursor)
}

void LCD_cmd(__uint16_t cmd)
{       HAL_GPIO_WritePin(GPIOB,GPIO_PIN_11, GPIO_PIN_RESET);
        cmd = (cmd << 8) ;
        GPIOB->ODR =  (cmd & 0xf000);
        LCD_Strobe();
        cmd = (cmd << 4) ;
     // printf("GPIOB->ODR Value %d \n\r",cmd);
        GPIOB->ODR =  (cmd & 0xf000);
        LCD_Strobe();
}


void LCD_data(__uint16_t LCD_Data)
{
     HAL_GPIO_WritePin(GPIOB,GPIO_PIN_11, GPIO_PIN_SET);
     LCD_Data = (LCD_Data << 8) ;
     GPIOB->ODR = (GPIOB->ODR & 0x0fff) | (LCD_Data & 0xf000);
    // LCD_Data =GPIOB->ODR;
    // printf("GPIOB->ODR Value %d \n\r",LCD_Data);
     LCD_Strobe();
     LCD_Data = (LCD_Data << 4) ;
     GPIOB->ODR = (GPIOB->ODR & 0x0fff) | (LCD_Data & 0xf000);
     LCD_Strobe();

}


void LCD_Clear(void)
{
    LCD_cmd(0x01);
    HAL_Delay(5);
}

void LCD_String(const char *ptr)  // ptr pointing the address of displaying string
{
    while (*ptr)             // check weather the endo of file then exit the loop
    {
        LCD_data(*ptr++);    // Sending data to LCD_data functions
    }
}

Whener i check the GPIOB->ODR value it shows some grabage value how to clear it ? is that the problem

 

[FvM]

VDD are connected inversely, the MCU power supply is not connected

Proteus simulator doesn't care. Hopefully the real circuit is wired correctly.

 

[thannara123]

VSS and VDD are connected inversely, the MCU power supply is not connected

it was corrected earlier .

 

[KlausST]

would you agree that this is much more easier to read?

 

[thannara123]

would you agree that this is much more easier to read?

View attachment 185274

Sir program says the connection details thats y i not metioned will try tp post again neatly and clearly

 

[thannara123]

Solved .
The problem Dont try STM32 on Proteus ,It not properly work ,
work on real Hardware .

But I learned a lot of . Thanks great foroum members

 

[thannara123]

Hai I changed the code as follows

void lcd_put(__uint16_t  lcd_data ,char rs)
{
    if(rs==0) // check weather it is command
    { HAL_GPIO_WritePin(GPIOB,RS_Pin, RESET);}// command}
    if(rs==1)
    {HAL_GPIO_WritePin(GPIOB,RS_Pin, SET); }// for data}

    lcd_data = (lcd_data << 8) ;
    GPIOB->ODR |=  (lcd_data & 0xf000); // send the higher nibbile to the GPIOB P15 is D7 ---GPIOB P12 is D4
        HAL_GPIO_WritePin(GPIOB,EN_Pin, SET);// LCD Enable PIN to High
        HAL_Delay(1);
        HAL_GPIO_WritePin(GPIOB,EN_Pin, RESET);       // LCD Enable High to Low

    lcd_data = (lcd_data << 4) ;  //send the lower nibbile to the GPIOB P15 is D7 ---GPIOB P12 is D4
    GPIOB->ODR |=  (lcd_data & 0xf000);
        HAL_GPIO_WritePin(GPIOB,EN_Pin, SET);// LCD Enable PIN to High
        HAL_Delay(1);
        HAL_GPIO_WritePin(GPIOB,EN_Pin, RESET);       // LCD Enable High to Low

}

is it make any optimization or any sense ?