【GD32L233C-START Review】5. IIC driving OLED

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【GD32L233C-START Review】5. IIC driving OLED [Copy link]

This post explains the driving of OLED.

This article is just an example. It adds OLED function based on my second post in this series. Click to jump: https://bbs.eeworld.com.cn/thread-1192155-1-1.html

1. Create an IIC file

Create four new files: myiic.c, myiic.h, app_oled.c, app_oled.h

The myiic.c and myiic.h files are mainly some logical processing of the software iic

app_oled.c and app_oled.h are some of the processing for OLED display and initialization

Then add the four files created above to the app group

2. Write IIC communication logic program

There are many detailed explanations on IIC related knowledge on the Internet. You can search and learn by yourself. This article only talks about code implementation.

IIC wiring:

SCL ---- PB10

SDA ---- PB11

myiic.c

#include "myiic.h"
#include "systick.h"

/* 	SCL - PB10
	SDA - PB11
*/

/*init IIC*/
void IIC_Init(void)
{					     	
	rcu_periph_clock_enable(RCU_GPIOB);   
	gpio_mode_set(GPIOB, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO_PIN_10|GPIO_PIN_11); 
	gpio_output_options_set(GPIOB, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_10|GPIO_PIN_11); 	
}
/*IIC start signal*/
void IIC_Start(void)
{
	SET_IIC_SDA();	  	  
	SET_IIC_SCL();
 	CLR_IIC_SDA();//START:when CLK is high,DATA change form high to low 
	CLR_IIC_SCL();//钳住I2C总线，准备发送或接收数据 
}	  
/*IIC stop signal*/
void IIC_Stop(void)
{
	SET_IIC_SCL(); 
	CLR_IIC_SDA();//STOP:when CLK is high DATA change form low to high
	SET_IIC_SDA();//发送I2C总线结束信号						   	
}

u8 IIC_Wait_Ack(void)
{
	CLR_IIC_SCL();				   
	return 0;  
} 
/*ack signal*/
void IIC_Ack(void)
{
	CLR_IIC_SCL();
	SDA_OUT();
	CLR_IIC_SDA();
	SET_IIC_SCL();
	CLR_IIC_SCL();
}
//不产生ACK应答		    
void IIC_NAck(void)
{
	CLR_IIC_SCL();
	SDA_OUT();
	SET_IIC_SDA();
	SET_IIC_SCL();
	CLR_IIC_SCL();
}					 				     
//IIC发送一个字节
//返回从机有无应答
//1，有应答
//0，无应答			  
void IIC_Send_Byte(u8 txd)
{                        
    u8 t;       
    CLR_IIC_SCL();//拉低时钟开始数据传输
    for(t=0;t<8;t++)
    {              
		if((txd&0x80)>>7)
			SET_IIC_SDA();
		else
			CLR_IIC_SDA();
        txd<<=1; 	  
		SET_IIC_SCL();
		CLR_IIC_SCL();	
    }	 
} 	    
//读1个字节，ack=1时，发送ACK，ack=0，发送nACK   
u8 IIC_Read_Byte(unsigned char ack)
{
	unsigned char i,receive=0;
	SDA_IN();//SDA设置为输入
    for(i=0;i<8;i++ )
	{
        CLR_IIC_SCL(); 
		SET_IIC_SCL();
        receive<<=1;
        if(READ_SDA)
			receive++;   
    }					 
    if (!ack)
        IIC_NAck();//发送nACK
    else
        IIC_Ack(); //发送ACK   
    return receive;
}

myiic.h

#ifndef __MYIIC_H
#define __MYIIC_H

#include "gd32l23x.h"
 
typedef uint8_t u8;
typedef uint16_t u16;
typedef uint32_t u32;
 
//IO操作函数	 
#define SET_IIC_SCL() gpio_bit_set(GPIOB, GPIO_PIN_10)//输出1
#define CLR_IIC_SCL() gpio_bit_reset(GPIOB, GPIO_PIN_10)//输出0

#define SET_IIC_SDA() gpio_bit_set(GPIOB, GPIO_PIN_11)//输出1
#define CLR_IIC_SDA() gpio_bit_reset(GPIOB, GPIO_PIN_11)//输出0

#define READ_SDA   gpio_input_bit_get(GPIOB, GPIO_PIN_11)  //输入SDA 

//IO方向设置
#define SDA_IN()      gpio_mode_set(GPIOB, GPIO_MODE_INPUT, GPIO_PUPD_PULLUP, GPIO_PIN_11)//配置为输入
#define SDA_OUT()     { gpio_mode_set(GPIOB, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO_PIN_11);\
						gpio_output_options_set(GPIOB, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_11);} //配置为输出
    
//IIC所有操作函数
void IIC_Init(void);                //初始化IIC的IO口				 
void IIC_Start(void);				//发送IIC开始信号
void IIC_Stop(void);	  			//发送IIC停止信号
void IIC_Send_Byte(unsigned char txd);			//IIC发送一个字节
unsigned char IIC_Read_Byte(unsigned char ack);//IIC读取一个字节
unsigned char IIC_Wait_Ack(void); 				//IIC等待ACK信号
void IIC_Ack(void);					//IIC发送ACK信号
void IIC_NAck(void);				//IIC不发送ACK信号

void IIC_Write_One_Byte(unsigned char daddr,unsigned char addr,unsigned char data);
unsigned char IIC_Read_One_Byte(unsigned char daddr,unsigned char addr);	  

#endif

3. OLED display logic program

OLED's SCL pin --- PB10

OLED's SDA pin --- PB11

app_oled.c

//OLED
#include "codetab.h"
#include "app_oled.h"
#include "myiic.h"
#include "systick.h"
   
u8 OLED_GRAM[128][8];	

/*********************OLED写数据函数************************************/ 
void OLED_WrDat(unsigned char IIC_Data)
{
	IIC_Start();
	IIC_Send_Byte(0x78);
	IIC_Wait_Ack();
	IIC_Send_Byte(0x40);			//write data
	IIC_Wait_Ack();
	IIC_Send_Byte(IIC_Data);
	IIC_Wait_Ack();
	IIC_Stop();
}
/*********************OLED写命令函数************************************/
void OLED_WrCmd(unsigned char IIC_Command)
{
	IIC_Start();
	IIC_Send_Byte(0x78);            //Slave address,SA0=0
	IIC_Wait_Ack();
	IIC_Send_Byte(0x00);			//write command
	IIC_Wait_Ack();
	IIC_Send_Byte(IIC_Command);
	IIC_Wait_Ack();
	IIC_Stop();
}

//--------------------------------------------------------------
// Prototype      : void OLED_OFF(void)
// Calls          : 
// Parameters     : none
// Description    : 让OLED休眠 -- 休眠模式下,OLED功耗不到10uA
//--------------------------------------------------------------
void OLED_OFF(void)
{
	OLED_WrCmd(0X8D);  
	OLED_WrCmd(0X10);  
	OLED_WrCmd(0XAE);  
}


//--------------------------------------------------------------
// Prototype      : void OLED_ON(void)
// Calls          : 
// Parameters     : none
// Description    : 将OLED从休眠中唤醒
//--------------------------------------------------------------
void OLED_ON(void)
{
	OLED_WrCmd(0X8D); 
	OLED_WrCmd(0X14);  
	OLED_WrCmd(0XAF);  
}

//x1,y1,x2,y2 填充区域的对角坐标
//确保x1<=x2;y1<=y2 0<=x1<=127 0<=y1<=63	 	 
//dot:0,清空;1,填充	  
void OLED_Fill(u8 x1,u8 y1,u8 x2,u8 y2,u8 dot)  
{  
	u8 x,y;  
	for(x=x1;x<=x2;x++)
		for(y=y1;y<=y2;y++)
			OLED_DrawPoint(x,y,dot);											    
	OLED_Refresh_Gram();//更新显示
}

//清屏函数,清完屏,整个屏幕是黑色的!和没点亮一样!!!	  
void OLED_Clear(void)  
{  
	u8 i,n;  
	for(i=0;i<8;i++)
		for(n=0;n<128;n++)
			OLED_GRAM[n][i]=0X00;  
	OLED_Refresh_Gram();//更新显示
}

/*********************OLED初始化************************************/
void OLED_Init(void)
{
//	IIC_Init();
//	delay_1ms(100);

	OLED_WrCmd(0xAE); //关闭显示
	OLED_WrCmd(0xD5); //设置时钟分频因子,震荡频率
	OLED_WrCmd(80);   //[3:0],分频因子;[7:4],震荡频率
	OLED_WrCmd(0xA8); //设置驱动路数
	OLED_WrCmd(0X3F); //默认0X3F(1/64) 
	OLED_WrCmd(0xD3); //设置显示偏移
	OLED_WrCmd(0X00); //默认为0

	OLED_WrCmd(0x40); //设置显示开始行 [5:0],行数.
													    
	OLED_WrCmd(0x8D); //电荷泵设置
	OLED_WrCmd(0x14); //bit2，开启/关闭
	OLED_WrCmd(0x20); //设置内存地址模式
	OLED_WrCmd(0x02); //[1:0],00，列地址模式;01，行地址模式;10,页地址模式;默认10;
	OLED_WrCmd(0xA1); //段重定义设置,bit0:0,0->0;1,0->127;
	OLED_WrCmd(0xC0); //设置COM扫描方向;bit3:0,普通模式;1,重定义模式 COM[N-1]->COM0;N:驱动路数
	OLED_WrCmd(0xDA); //设置COM硬件引脚配置
	OLED_WrCmd(0x12); //[5:4]配置
		 
	OLED_WrCmd(0x81); //对比度设置
	OLED_WrCmd(0xEF); //1~255;默认0X7F (亮度设置,越大越亮)
	OLED_WrCmd(0xD9); //设置预充电周期
	OLED_WrCmd(0xf1); //[3:0],PHASE 1;[7:4],PHASE 2;
	OLED_WrCmd(0xDB); //设置VCOMH 电压倍率
	OLED_WrCmd(0x30); //[6:4] 000,0.65*vcc;001,0.77*vcc;011,0.83*vcc;

	OLED_WrCmd(0xA4); //全局显示开启;bit0:1,开启;0,关闭;(白屏/黑屏)
	OLED_WrCmd(0xA6); //设置显示方式;bit0:1,反相显示;0,正常显示	    						   
	OLED_WrCmd(0xAF); //开启显示 
	
	OLED_Clear();
} 

//更新显存到LCD		 
void OLED_Refresh_Gram(void)
{
	u8 i,n;		    
	for(i=0;i<8;i++)  
	{  
		OLED_WrCmd (0xb0+i);    //设置页地址（0~7）
		OLED_WrCmd (0x00);      //设置显示位置—列低地址
		OLED_WrCmd (0x10);      //设置显示位置—列高地址   
		for(n=0;n<128;n++)
			OLED_WrDat(OLED_GRAM[n][i]); 
	}   
}

//画点 
//x:0~127
//y:0~63
//t:1 填充 0,清空				   
void OLED_DrawPoint(u8 x,u8 y,u8 t)
{
	u8 pos,bx,temp=0;
	if(x>127||y>63)return;//超出范围了.
	pos=7-y/8;
	bx=y%8;
	temp=1<<(7-bx);
	if(t)
		OLED_GRAM[x][pos]|=temp;
	else 
		OLED_GRAM[x][pos]&=~temp;	    
}

//在指定位置显示一个字符,包括部分字符
//x:0~127
//y:0~63
//mode:0,反白显示;1,正常显示				 
//size:选择字体 16/12 
void OLED_ShowChar(u8 x,u8 y,u8 chr,u8 size,u8 mode)
{      			    
	u8 temp,t,t1;
	u8 y0=y;
	u8 csize=(size/8+((size%8)?1:0))*(size/2);		//得到字体一个字符对应点阵集所占的字节数
	chr=chr-' ';//得到偏移后的值		 
    for(t=0;t<csize;t++)
    {   
		if(size==12)temp=asc2_1206[chr][t]; 	 	//调用1206字体
		else if(size==16)temp=asc2_1608[chr][t];	//调用1608字体
		else if(size==24)temp=asc2_2412[chr][t];	//调用2412字体
		else return;								//没有的字库
        for(t1=0;t1<8;t1++)
		{
			if(temp&0x80)
				OLED_DrawPoint(x,y,mode);
			else OLED_DrawPoint(x,y,!mode);
			temp<<=1;
			y++;
			if((y-y0)==size)
			{
				y=y0;
				x++;
				break;
			}
		}  	 
    }          
}

//m^n函数
u32 mypow(u8 m,u8 n)
{
	u32 result=1;	 
	while(n--)result*=m;    
	return result;
}				  
//显示2个数字
//x,y :起点坐标	 
//len :数字的位数
//size:字体大小
//mode:模式	0,填充模式;1,叠加模式
//num:数值(0~4294967295);	 		  
void OLED_ShowNum(u8 x,u8 y,u32 num,u8 len,u8 size)
{         	
	u8 t,temp;
	u8 enshow=0;						   
	for(t=0;t<len;t++)
	{
		temp=(num/mypow(10,len-t-1))%10;
		if(enshow==0&&t<(len-1))
		{
			if(temp==0)
			{
				OLED_ShowChar(x+(size/2)*t,y,'0',size,1);
				continue;
			}else enshow=1; 
		 	 
		}
	 	OLED_ShowChar(x+(size/2)*t,y,temp+'0',size,1); 
	}
} 
//显示字符串
//x,y:起点坐标  
//size:字体大小 
//*p:字符串起始地址 
void OLED_ShowString(u8 x,u8 y,const u8 *p,u8 size,uint8_t mode)
{	
    while((*p<='~')&&(*p>=' '))//判断是不是非法字符!
    {       
        if(x>(128-(size/2))){x=0;y+=size;}
        if(y>(64-size)){y=x=0;OLED_Clear();}
        OLED_ShowChar(x,y,*p,size,mode);	 
        x+=size/2;
        p++;
    }  
	
}


//显示图形
//得到字体一个字符对应点阵集所占的字节数
//len--传入的数据的总长度
void OLED_ShowBMP(u8 x,u8 y,u8 mode,u8 bmp[][16],u32 len)
{
	u16 t,t1;
	u8 y0=y;
	u8 temp;
	u16 len2=len/16;		//数组的列数
	
	for(t=0;t<len;t++)
	{   
		temp=bmp[0][t];	
		for(t1=0;t1<8;t1++)
		{
			if(temp&0x80)
				OLED_DrawPoint(x,y,mode);
			else OLED_DrawPoint(x,y,!mode);
			temp<<=1;
			y++;
			if((y-y0) == len2)
			{
				y = y0;
				x ++;
				break;
			}
		}  	 
	} 
}

app_oled.h

#ifndef _APP_OLED_H_
#define _APP_OLED_H_

#include "stdint.h"

extern void OLED_Init(void);

extern void OLED_Fill(unsigned char x1,unsigned char y1,unsigned char x2,unsigned char y2,unsigned char dot);
extern void OLED_Clear(void);

extern void OLED_Refresh_Gram(void);		   
extern void OLED_DrawPoint(unsigned char x,unsigned char y,unsigned char t);
extern void OLED_ShowChar(unsigned char x,unsigned char y,unsigned char chr,unsigned char size,unsigned char mode);
extern void OLED_ShowNum(unsigned char x,unsigned char y,unsigned int num,unsigned char len,unsigned char size);
extern void OLED_ShowString(unsigned char x,unsigned char y,const unsigned char *p,unsigned char size,unsigned char mode);	
extern void OLED_ShowBMP(unsigned char x,unsigned char y,unsigned char mode,unsigned char bmp[][16],unsigned int len);

#endif

The above code implements some function encapsulation for displaying characters: character display, string display, number display, clearing OLED, and refreshing OLED, etc.

4. The main function implements OLED string display

Add the following statement before the main() while loop:

	OLED_ShowString(0, 0, "GD32L233C-START", 16, 1);
	OLED_ShowString(0, 16, "EEWORLD", 24, 0);
	OLED_Refresh_Gram();

The meaning is:

1). Display the string GD32L233C-START at 0,0 coordinates with a dot size of 16 pixels. The last parameter 1 means that the written characters are not inverted.

2). Display the string EEWORLD at 24 pixels at the coordinates 0,16. The last parameter 0 indicates the reverse display.

3). Write the above displayed string to the OLED display

5. Display effect