[STM32 learning] (18) STM32 realizes LCD12864 display - parallel implementation of 8-bit bus

The last blog is to realize serial display , Now let's implement a parallel display ,8 Implementation of bit bus , In fact, the implementation of four bit bus is similar to 1602 almost , There is no need to realize .

Let's stick it first 1284 Some information about . and 1602 And similar to .

Display address ：

Specific information can be inquired online , A lot of information .

Hardware ：STM32L052K8*    This and others STM32 almost , It's just that this single chip microcomputer is IO When writing values, you cannot write two bytes at a time , You can only write one by one , This and F Series of microcontrollers are different , But there are solutions . You can see the following code implementation .

connection ：

PA0-PA7    Pick up      D0-D7

PB1          Pick up      RS

PB2          Pick up      RW

PB3          Pick up      EN

The code is as follows ：

lcd12864.c

#include "lcd12864.h"
#include "stm32l052xx.h"
#include "stm32l0xx_hal_gpio.h" 

uint16_t temp;


// Time delay 
void delay(uint32_t m)
{
	uint32_t i,j;
	for(i=0;i<m;i++)
		for(j=0;j<10;j++);
}
/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3  
                          |GPIO_PIN_4|GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7, GPIO_PIN_RESET);

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOB, RS_Pin|RW_Pin|EN_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pins : PA0 PA1 PA2 PA3 
                           PA4 PA5 PA6 PA7 */
  GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3 
                          |GPIO_PIN_4|GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /*Configure GPIO pins : RS_Pin RW_Pin EN_Pin */
  GPIO_InitStruct.Pin = RS_Pin|RW_Pin|EN_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

}
//LCD initialization 
void LCD_Init(void)
{
	LCD_wcmd(0x30);// Feature set ： Basic instruction set 
	HAL_Delay(10);
	//LCD_wcmd(0x08);
	//HAL_Delay(10);
	//LCD_wcmd(0x10);
	//HAL_Delay(10);
	LCD_wcmd(0x0C);// Show on , Guan cursor 
	HAL_Delay(10);
	LCD_wcmd(0x01);// Clear the display 
	HAL_Delay(10);
	//LCD_wcmd(0x06);
	//HAL_Delay(10);
}
// Busy judgment 
void CheckBusy(void)
{
	uint8_t status;
	HAL_GPIO_WritePin(RS_GPIO_Port,RS_Pin,GPIO_PIN_RESET);
	HAL_GPIO_WritePin(RW_GPIO_Port,RW_Pin,GPIO_PIN_SET);	// Read the data ,RW=1
	HAL_GPIO_WritePin(GPIOA,GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3|GPIO_PIN_4|GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7,GPIO_PIN_SET);
	do
	{
		HAL_GPIO_WritePin(EN_GPIO_Port,EN_Pin,GPIO_PIN_SET);
		HAL_Delay(5);
		status = HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_7);// receive BF position , Judge if you are busy 
		HAL_GPIO_WritePin(EN_GPIO_Port,EN_Pin,GPIO_PIN_RESET);
	}while(status & 0x80);
	
}
//LCD Write orders 
void LCD_wcmd(uint8_t cmd)
{
	CheckBusy();
	HAL_GPIO_WritePin(RS_GPIO_Port,RS_Pin,GPIO_PIN_RESET);
	HAL_GPIO_WritePin(RW_GPIO_Port,RW_Pin,GPIO_PIN_RESET);	// Read the data ,RW=0
	HAL_Delay(5);
	temp=(temp&0xff00)|cmd;//temp The lower eight digits of will be cleared cmd Put it in 
	Write_data(temp);
	//GPIO_Write(GPIOA,temp);// adopt GPIO_Write（） Function to send data to A port （ That is to say LCD Data port ）
	HAL_GPIO_WritePin(EN_GPIO_Port,EN_Pin,GPIO_PIN_SET);// Enable bit on 
	HAL_Delay(10);//10ms It should be able to send 
	HAL_GPIO_WritePin(EN_GPIO_Port,EN_Pin,GPIO_PIN_RESET);// The enable bit is off 
}
//LCD Writing data 
void LCD_wdat(uint8_t dat)
{
	CheckBusy();
	HAL_GPIO_WritePin(RS_GPIO_Port,RS_Pin,GPIO_PIN_SET);
	HAL_GPIO_WritePin(RW_GPIO_Port,RW_Pin,GPIO_PIN_RESET);
	HAL_Delay(5);
	temp=(temp&0xff00)|dat; //temp The lower eight digits of will be cleared dat Put it in 
	Write_data(temp);
	//GPIO_Write(GPIOA,temp);// adopt GPIO_Write（） Function to send data to A port （ That is to say LCD Data port ）
	HAL_GPIO_WritePin(EN_GPIO_Port,EN_Pin,GPIO_PIN_SET);// Enable bit on 
	HAL_Delay(10);//10ms It should be able to send 
	HAL_GPIO_WritePin(EN_GPIO_Port,EN_Pin,GPIO_PIN_RESET);// The enable bit is off 
}
// towards LCD12864 Write a row of data in （ Because you can't send only one byte of data at a time ）
void LCD_Wmessage(uint8_t* message,uint8_t address)
{
	LCD_wcmd(address);// Location to display , You want the content to appear in LCD Which line? , Send the starting address of the line by writing a command , Amazing , Is there any 
	while(*message>0)// This judgment is crucial , Judge whether your content has been sent 
	{
		LCD_wdat(*message); // Kernel or send byte function 
		message++; // The pointer works well ..
	}
}

void  Write_data(uint16_t temp)
{
	/*  high 8 Bit value judgment  */
	if((temp&0X0080) == 0X0080)			//	**** **** 1000 0000
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_7,GPIO_PIN_SET);
	}
	else
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_7,GPIO_PIN_RESET);
	}
	/*  high 7 Bit value judgment  */
	if((temp&0X0040) == 0X0040)			//	**** **** 1000 0000
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_6,GPIO_PIN_SET);
	}
	else
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_6,GPIO_PIN_RESET);
	}
	/*  high 6 Bit value judgment  */
	if((temp&0X0020) == 0X0020)			//	**** **** 1000 0000
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_5,GPIO_PIN_SET);
	}
	else
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_5,GPIO_PIN_RESET);
	}
	/*  high 5 Bit value judgment  */
	if((temp&0X0010) == 0X0010)			//	**** **** 1000 0000
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_4,GPIO_PIN_SET);
	}
	else
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_4,GPIO_PIN_RESET);
	}
	/*  high 4 Bit value judgment  */
	if((temp&0X0008) == 0X0008)			//	**** **** 1000 0000
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_3,GPIO_PIN_SET);
	}
	else
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_3,GPIO_PIN_RESET);
	}
	/*  high 3 Bit value judgment  */
	if((temp&0X0004) == 0X0004)			//	**** **** 1000 0000
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_2,GPIO_PIN_SET);
	}
	else
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_2,GPIO_PIN_RESET);
	}
	/*  high 2 Bit value judgment  */
	if((temp&0X0002) == 0X0002)			//	**** **** 1000 0000
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_1,GPIO_PIN_SET);
	}
	else
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_1,GPIO_PIN_RESET);
	}
	/*  high 1 Bit value judgment  */
	if((temp&0X0001) == 0X0001)			//	**** **** 1000 0000
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_0,GPIO_PIN_SET);
	}
	else
	{
		HAL_GPIO_WritePin(GPIOA,GPIO_PIN_0,GPIO_PIN_RESET);
	}
	
	
}

lcd12864.h

#include "main.h"

#define			LINE1		0x80 // The starting address of the first line , The same below 
#define			LINE2 		0x90
#define			LINE3 		0x88
#define			LINE4 		0x98

#define RS_Pin GPIO_PIN_1
#define RS_GPIO_Port GPIOB
#define RW_Pin GPIO_PIN_3
#define RW_GPIO_Port GPIOB
#define EN_Pin GPIO_PIN_5
#define EN_GPIO_Port GPIOB

void MX_GPIO_Init(void);
void LCD_Init(void);
void CheckBusy(void);
void LCD_wcmd(uint8_t cmd);
void LCD_wdat(uint8_t dat);
void LCD_Wmessage(uint8_t* message,uint8_t address);
void  Write_data(uint16_t temp);

main.c

int main(void)
{
  /* USER CODE BEGIN 1 */
	uint8_t dis3[]={" abed, I see a silver light ,"};
	uint8_t dis4[]={" The frost on the ground ,"};
	uint8_t dis5[]={" look at the bright moon ,"};
	uint8_t dis6[]={" Bow your head and think of your hometown ."};
  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  LCD_Init();
  /* USER CODE BEGIN 2 */
	//LCD_Wmessage(dis3,LINE1);
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
		LCD_Wmessage(dis3,LINE1); 
		LCD_Wmessage(dis4,LINE2);
		LCD_Wmessage(dis5,LINE3);
		LCD_Wmessage(dis6,LINE4);
  }
  /* USER CODE END 3 */
}

The display effect is as follows ：