【GD32L233C-START】11、硬件I2C驱动0.96吋OLED

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发布于 2022-04-04 15:57:09

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发布于 2022-04-04 15:57:09

文章被收录于专栏：物联网思考物联网思考

0、前言

关于OLED的详细驱动，可查看一文彻底了解SSD1306驱动0.96寸OLED，本文使用GD32L233硬件I2C驱动。

1、关于GD32L233CCT6的I2C接口

可以看出有两路I2C，分别是I2C0，I2C1。

2、开发板上I2C的引脚

可以看出，I2C1的引脚为PB10和PB11。

3、通用引脚复用为I2C

可以看出，是复用功能4。

4、代码实现

（1）初始化i2c

void I2cInit(void)
{
    rcu_periph_clock_enable(RCU_I2C1);
    rcu_periph_clock_enable(RCU_GPIOB);

    gpio_af_set(GPIOB, GPIO_AF_4, GPIO_PIN_10);
    gpio_af_set(GPIOB, GPIO_AF_4, GPIO_PIN_11);

    gpio_mode_set(GPIOB, GPIO_MODE_AF, GPIO_PUPD_PULLUP, GPIO_PIN_10);
    gpio_output_options_set(GPIOB, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, GPIO_PIN_10);
    gpio_mode_set(GPIOB, GPIO_MODE_AF, GPIO_PUPD_PULLUP, GPIO_PIN_11);
    gpio_output_options_set(GPIOB, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, GPIO_PIN_11);
	
    /* configure I2C timing */
    i2c_timing_config(I2C1, 0, 0x3, 0);
    i2c_master_clock_config(I2C1, 0x13, 0x36);
	
    /* configure I2C address */
    i2c_address_config(I2C1, I2C_OWN_ADDRESS7, I2C_ADDFORMAT_7BITS);
    /* configure slave address */
    i2c_master_addressing(I2C1, I2C_SLAVE_ADDRESS7, I2C_MASTER_TRANSMIT);
    /* configure number of bytes to be transferred */
    i2c_transfer_byte_number_config(I2C1, 2);
    /* enable I2C1 */
    i2c_enable(I2C1);	
}

（2）写OLED 下面分写命令和数据.

void SSD1306_WriteCmd(uint8_t var)
{
    /* wait until I2C bus is idle */
    while(i2c_flag_get(I2C1, I2C_FLAG_I2CBSY));
    /* send a start condition to I2C bus */
    i2c_start_on_bus(I2C1);
	
    /* wait until the transmit data buffer is empty */
    I2C_STAT(I2C1) |= I2C_STAT_TBE;
    while(!i2c_flag_get(I2C1, I2C_FLAG_TBE));

    /* data transmission */
    i2c_data_transmit(I2C1, 0x00);
    /* wait until the TI bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_TBE));
	
    i2c_data_transmit(I2C1, var);
    /* wait until the TI bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_TBE));
	
    /* wait for transfer complete flag */
    while(!i2c_flag_get(I2C1, I2C_FLAG_TC));
    /* send a stop condition to I2C bus */
    i2c_stop_on_bus(I2C1);
    /* wait until stop condition generate */
    while(!i2c_flag_get(I2C1, I2C_FLAG_STPDET));
    /* clear the STPDET bit */
    i2c_flag_clear(I2C1, I2C_FLAG_STPDET);
}

void SSD1306_WriteData(uint8_t var)
{
    /* wait until I2C bus is idle */
    while(i2c_flag_get(I2C1, I2C_FLAG_I2CBSY));
    /* send a start condition to I2C bus */
    i2c_start_on_bus(I2C1);
    /* wait until the transmit data buffer is empty */
    I2C_STAT(I2C1) |= I2C_STAT_TBE;
    while(!i2c_flag_get(I2C1, I2C_FLAG_TBE));

    /* data transmission */
    i2c_data_transmit(I2C1, 0x40);
    /* wait until the TI bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_TBE));
	
    i2c_data_transmit(I2C1, var);
    /* wait until the TI bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_TBE));
	
    /* wait for transfer complete flag */
    while(!i2c_flag_get(I2C1, I2C_FLAG_TC));
    /* send a stop condition to I2C bus */
    i2c_stop_on_bus(I2C1);
    /* wait until stop condition generate */
    while(!i2c_flag_get(I2C1, I2C_FLAG_STPDET));
    /* clear the STPDET bit */
    i2c_flag_clear(I2C1, I2C_FLAG_STPDET);
}

（3）OLED相关驱动

//坐标设置：也就是在哪里显示
void OledSetPos(uint8_t x, uint8_t y) 
{ 
  //以下3个寄存器只在页寻址的模式下有效	
  SSD1306_WriteCmd(0xb0+y);             //页地址设置     0xb0~0xb7
  SSD1306_WriteCmd(((x&0xf0)>>4)|0x10); //列高位地址设置
  SSD1306_WriteCmd((x&0x0f));           //列低位地址设置
} 
 
//开启Oled显示
void OledDisplayOn(void)
{
  SSD1306_WriteCmd(0X8D);  //SET DCDC命令
  SSD1306_WriteCmd(0X14);  //DCDC ON
  SSD1306_WriteCmd(0XAF);  //DISPLAY ON
}
 
//关闭Oled显示   
void OledDisplayOff(void)
{
  SSD1306_WriteCmd(0X8D);  //SET DCDC命令
  SSD1306_WriteCmd(0X10);  //DCDC OFF
  SSD1306_WriteCmd(0XAE);  //DISPLAY OFF
}
 
//清屏函数,清完屏,整个屏幕是黑色的!和没点亮一样  
void OledClear(void)  
{  
  uint8_t i,n;	
  
  for(i=0;i<8;i++)  
  {  
    SSD1306_WriteCmd (0xb0+i);    //设置页地址（0~7）
    SSD1306_WriteCmd (0x00);      //设置显示位置—列低地址
    SSD1306_WriteCmd (0x10);      //设置显示位置—列高地址   
    for(n=0;n<128;n++)
      SSD1306_WriteData(0); 
  } //更新显示
}
 
//在指定位置显示一个字符,包括部分字符
//x:0~127，y:0~7
//Char_Size:选择字体 16/12 
void OledShowChar(uint8_t x,uint8_t y,uint8_t chr,uint8_t Char_Size)
{      	
  uint8_t c=0,i=0;	
  
  c=chr-' ';//得到偏移后的值			
  if(x>MAX_COLUMN-1)
  {
    x=0;
    y=y+2;
  }
  if(Char_Size ==16)
  {
    OledSetPos(x,y);	
    for(i=0;i<8;i++)
    {
      SSD1306_WriteData(F8X16[c*16+i]);//先写上半部分
    }
    
    OledSetPos(x,y+1);
    for(i=0;i<8;i++)
    {
      SSD1306_WriteData(F8X16[c*16+i+8]);//后写下半部分
    }
  }
  else
  {	
    OledSetPos(x,y);
    for(i=0;i<6;i++)
    {
      SSD1306_WriteData(F6x8[c][i]);
    }
  }
}
 
//显示一个字符串
void OledShowString(uint8_t x,uint8_t y,char *str,uint8_t Char_Size)
{
  unsigned char j=0;
  
  while (str[j]!='\0')
  {
    OledShowChar(x,y,str[j],Char_Size);
    x+=8;
    if(x>120)
    {
      x=0;
      y+=2;
    }
    j++;//移动一次就是一个page，取值0-7
  }
}
 
//显示汉字
//由于汉字是16*16大小的，所以最多显示4行汉字
//index:在汉字取模中的索引
void OledShowCN(uint8_t x,uint8_t y,uint8_t index)
{      			    
  uint8_t t;
	
  OledSetPos(x,y);	
  for(t=0;t<16;t++)
  {
    SSD1306_WriteData(Hzk[index][t]);
  }	
  
  OledSetPos(x,y+1);	
  for(t=0;t<16;t++)
  {	
    SSD1306_WriteData(Hzk[index][t+16]);
  }					
}

（4）OLED初始化

void OledInit(void)
{
  DelayMs(300);
  DelayMs(300);

  //SSD1306复位之后，默认的是页寻址方式
  
  SSD1306_WriteCmd(0xAE);//--display off
  
  SSD1306_WriteCmd(0x00);//--set low column address
  SSD1306_WriteCmd(0x10);//--set high column address
  SSD1306_WriteCmd(0x40);//--set start line address  
  
  SSD1306_WriteCmd(0xB0);//--set page address
  
  SSD1306_WriteCmd(0x81);// contract control
  SSD1306_WriteCmd(0xFF);//--128   
  SSD1306_WriteCmd(0xA1);//set segment re-map  0 to 127 
  SSD1306_WriteCmd(0xA6);//set normal  display  
  SSD1306_WriteCmd(0xA8);//set multiplex ratio(1 to 64)
  SSD1306_WriteCmd(0x3F);//--1/32 duty
  
  SSD1306_WriteCmd(0xC8);//Com scan direction
  SSD1306_WriteCmd(0xD3);//set display offset
  SSD1306_WriteCmd(0x00);//no offset
	
  SSD1306_WriteCmd(0xD5);//set display clock divide ratio/oscillator frequency  
  SSD1306_WriteCmd(0x80);//
	
  SSD1306_WriteCmd(0xD8);//set area color mode off
  SSD1306_WriteCmd(0x05);//
	
  SSD1306_WriteCmd(0xD9);//Set Pre-Charge Period
  SSD1306_WriteCmd(0xF1);//
	
  SSD1306_WriteCmd(0xDA);//set com pin  hardware configuartion
  SSD1306_WriteCmd(0x12);//
	
  SSD1306_WriteCmd(0xDB);//set Vcomh
  SSD1306_WriteCmd(0x30);//0x20,0.77xVcc
	
  SSD1306_WriteCmd(0x8D);//set charge pump enable
  SSD1306_WriteCmd(0x14);//
	
  SSD1306_WriteCmd(0xAF);//--turn on Oled panel
}

（5）显示测试

void OledDisplayTest(void)
{
	I2cInit();
	OledInit();
	
	OledClear(); 

	OledShowString(28,0,(char *)("EEWORLD"),16);
	OledShowString(40,2,(char *)("GD32"),16);
	OledShowString(40,4,(char *)("2022"),16);

	OledShowCN(24,6,0);
	OledShowCN(40,6,1);
	OledShowCN(56,6,2);
	OledShowCN(72,6,3);
}