[AB32VG1 development board review] OLED screen display driver

jinglixixi

[AB32VG1 development board review] OLED screen display driver [Copy link]

 

OLED screen is a self-luminous display device. It has many types. According to the interface, there are I2C interface and SPI interface. According to the color, it can be divided into monochrome, dual-color and color screens. According to the display specifications, it can be divided into 0.91, 0.96 inches, etc.

In order to save I/O ports, the display screen used here is a 0.91-inch monochrome screen with an I2C interface.

The connection relationship between the display screen and the development board is:

SDA--PE2

SCL--PE3

The statement that makes the corresponding pin output high and low levels is defined as:

uint8_t pin_scl;

uint8_t pin_sda;

#define OLED_SCLK_Clr() rt_pin_write(pin_scl, PIN_LOW)

#define OLED_SCLK_Set() rt_pin_write(pin_scl, PIN_HIGH)

#define OLED_SDIN_Clr() rt_pin_write(pin_sda, PIN_LOW)

#define OLED_SDIN_Set() rt_pin_write(pin_sda, PIN_HIGH)

The initialization function of the OLED screen is:

void OLED_Init(void)
{
 Write_IIC_Command(0xAE); //display off
 Write_IIC_Command(0x40);//--set start line address
 Write_IIC_Command(0xb0);//Set Page Start Address for Page Addressing Mode,0-7
 Write_IIC_Command(0xc8);//Set COM Output Scan Direction
 Write_IIC_Command(0x81);//--set contrast control register
 Write_IIC_Command(0xff);
 Write_IIC_Command(0xa1);//--set segment re-map 0 to 127
 Write_IIC_Command(0xa6);//--set normal display
 Write_IIC_Command(0xa8);//--set multiplex ratio(1 to 64)
 Write_IIC_Command(0x1F);
 Write_IIC_Command(0xd3);//-set display offset
 Write_IIC_Command(0x00);//-not offset
 Write_IIC_Command(0xd5);//--set display clock divide ratio/oscillator frequency
 Write_IIC_Command(0xf0);//--set divide ratio
 Write_IIC_Command(0xd9);//--set pre-charge period
 Write_IIC_Command(0x22);
 Write_IIC_Command(0xda);//--set com pins hardware configuration
 Write_IIC_Command(0x02);
 Write_IIC_Command(0x8d);//--set DC-DC enable
 Write_IIC_Command(0x14);
 Write_IIC_Command(0xdb);//--set vcomh
 Write_IIC_Command(0x49);//0x20,0.77xVcc
 Write_IIC_Command(0xaf);//--turn on oled panel
}

The function of simulating I2C byte data with I/O port is:

void Write_IIC_Byte(unsigned char IIC_Byte)
{
 unsigned char i;
 unsigned char m,da;
 da=IIC_Byte;
 OLED_SCLK_Clr();
 for(i=0;i<8;i++)
 {
 m=da;
 m=m&0x80;
 if(m==0x80)
 {
          OLED_SDIN_Set();
        }
 else OLED_SDIN_Clr();
 rt_hw_us_delay(2);
 da=da<<1;
 OLED_SCLK_Set();
 rt_hw_us_delay(2);
 OLED_SCLK_Clr();
 rt_hw_us_delay(2);
 }
}

The function to clear the OLED screen is:

void OLED_Clear(void)
{
 uint8_t i,n;
 for(i=0;i<8;i++)
 {
 OLED_WR_Byte (0xb0+i,OLED_CMD);
 OLED_WR_Byte (0x00,OLED_CMD);
 OLED_WR_Byte (0x10,OLED_CMD);
 for(n=0;n<128;n++)OLED_WR_Byte(0,OLED_DATA);
 }
}

The function that makes the OLED screen display characters is:

void OLED_ShowChar(uint8_t x,uint8_t y,uint8_t chr,uint8_t Char_Size)
{
 unsigned char c=0,i=0;
 c=chr-' ';
 if(x>Max_Column-1)
      {
       x=0;
       y=y+2;
      }
if(Char_Size ==16)
 {
 OLED_Set_Pos(x,y);
 for(i=0;i<8;i++)
 OLED_WR_Byte(F8X16[c*16+i],OLED_DATA);
 OLED_Set_Pos(x,y+1);
 for(i=0;i<8;i++)
 OLED_WR_Byte(F8X16[c*16+i+8],OLED_DATA);
 }
 else 
      {
 OLED_Set_Pos(x,y);
 for(i=0;i<6;i++)
 OLED_WR_Byte(F6x8[c],OLED_DATA);
 }
}

The function that makes the OLED screen display the string is:

void OLED_ShowString(uint8_t x,uint8_t y,uint8_t *chr,uint8_t Char_Size)
{
 unsigned char j=0;
 while (chr[j]!='\0')
 { 
          OLED_ShowChar(x,y,chr[j],Char_Size);
 x+=8;
 if(x>120){x=0;y+=2;}
 j++;
 }
}

The main program to achieve the graphic effect is:

int main(void)
{
 uint32_t cnt = 0;
 uint32_t i,j;
 pin = rt_pin_get("PE.1");
 rt_pin_mode(pin, PIN_MODE_OUTPUT);
 pin_scl = rt_pin_get("PE.3");
 pin_sda = rt_pin_get("PE.2");
 rt_pin_mode(pin_scl, PIN_MODE_OUTPUT);
 rt_pin_mode(pin_sda, PIN_MODE_OUTPUT);
 OLED_Init();
 OLED_Clear();
 OLED_ShowString(0,0,"AB32VG1 RISC-V",16);
 OLED_ShowString(0,2,"OLED DISPLAY",16);
 while(1)
 {
 rt_pin_write(pin, PIN_LOW);
 rt_thread_mdelay(500);
 rt_pin_write(pin, PIN_HIGH);
  rt_thread_mdelay(500);
 }
}

Pin connection and display effect diagram

w494143467

Exclusive for OLED brother!

jinglixixi

w494143467 posted on 2021-9-6 11:08 Exclusive for OLED brother!

Haha, because it will be used in the following applications.