[Yichuang ET6001 Review] Serial digital tube display driver

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[Yichuang ET6001 Review] Serial digital tube display driver [Copy link]

 

I originally planned to use the GPIO port to implement an I2C interface OLED screen display, but after several unsuccessful debugging attempts, I had to give up this option.

Therefore, the serial digital tube display module was selected as a breakthrough, and its display effect was good after testing.

The display module uses MAX7219 as the main control chip, can display 8-bit values, and supports cascading. In addition to the power supply, it only needs 3 GPIO ports, so it saves pin resources.

Figure 1 Serial digital tube display module

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

SCL---GPIO2_2

SDA---GPIO2_3

CS---GPIO2_4

In order to provide high and low level outputs to the serial digital tube display module, the defined statements are:

#define CLK_SetLow GPIO_WritePin(GPIO2, GPIO_PIN_02, RESET)

#define CLK_SetHigh GPIO_WritePin(GPIO2, GPIO_PIN_02, SET)

#define DIN_SetLow GPIO_WritePin(GPIO2, GPIO_PIN_03, RESET)

#define DIN_SetHigh GPIO_WritePin(GPIO2, GPIO_PIN_03, SET)

#define CS_SetLow GPIO_WritePin(GPIO2, GPIO_PIN_04, RESET)

#define CS_SetHigh GPIO_WritePin(GPIO2, GPIO_PIN_04, SET)

Since the key chip used in the serial digital tube display module is MAX7219, a function for serially sending byte data is configured for it, and its content is:

static void Write_Max7219_byte(char DATA)
{
  char i;
  CS_SetLow;
  delay(10);
  for(i=8;i>=1;i--)
  {
      CLK_SetLow;
      if(DATA&0x80)
         DIN_SetHigh;
      else
         DIN_SetLow;
      delay(10);
      DATA=(char)(DATA<<1);
      CLK_SetHigh;
      delay(10);
  }
}

Based on the function Write_Max7219_byte(), the function that sends data to the specified address is:

static void Write_Max7219(char address,char dat)
{
  CS_SetLow;
  Write_Max7219_byte(address);
  Write_Max7219_byte(dat);
  CS_SetHigh;
}

For the serial digital tube display module, its initialization function is:

static void Init_MAX7219(void)
{
   Write_Max7219(0x09, 0xff);
   Write_Max7219(0x0a, 0x02);
   Write_Max7219(0x0b, 0x07);
   Write_Max7219(0x0c, 0x01);
   Write_Max7219(0x0f, 0x00);
}

To test the serial digital tube display module, the corresponding main program is:

int main(void)
{
    EVB_LEDInit();
    Init_MAX7219();
    Write_Max7219(1,1);
    Write_Max7219(2,2);
    Write_Max7219(3,3);
    Write_Max7219(4,4);
    Write_Max7219(5,5);
    Write_Max7219(6,6);
    Write_Max7219(7,7);
    Write_Max7219(8,8);
    while (1)
    {
        GPIO_TogglePin(GPIO_LED_PORT, GPIO_LED_PIN);
        __Delay(0x5FFFFF);
}
}

After the program is compiled and run, the effect is shown in Figure 2.

Figure 2 Display effect diagram

In this way, the display driver of the serial digital tube module is realized, and it can be used to complete the numerical display later.

秦天qintian0303

What about the analog IIC interface? Different hardware chips have different problems

jinglixixi

Qintianqintian0303 posted on 2024-10-27 12:25 How about simulating IIC interface? Different hardware chips have different problems

Simulated, so it is more convenient to transplant and use.