Project 10：8×8 Dot-matrix Display

Introduction

The dot-matrix display is an electronic digital display device that can show information on machines, clocks and many other devices. In this project, we will use the pico board control the 8x8 LED dot matrix to make a“❤”pattern.

Components Required

image-20230508175551128

Raspberry Pi Pico*1

Raspberry Pi Pico Expansion Board*1

image-20230508175607657

image-20230508175557880

8*8 Dot-matrix Display *1

M-F Dupont Wires

USB Cable*1

Component Knowledge

8*8 Dot-matrix display module:

The 8*8 dot matrix is composed of 64 LEDs, and each LED is placed at the intersection of a row and a column. When using a single-chip microcomputer to drive an 8*8 dot matrix, we need to use a total of 16 digital ports, which greatly wastes the data of the single-chip microcomputer. For this reason, we specially designed this module, using the HT16K33 chip to drive an 8*8 dot matrix, and only need to use the I2C communication port of the single-chip microcomputer to control the dot matrix, which greatly saves the microcontroller resources.

Specifications:

Working voltage: DC 5V

Current: 200MA

Maximum power: 1W

Schematic diagram:

image-20230509091553167

Some modules come with 3 DIP switches which allow you to toggle the switches at will. They are used to set the I2C communication address. The setting method is as follows. In our module, the module has fixed the communication address, A0, A1, A2 are all grounded, that is, the address is 0x70.

image-20230508175834266

Circuit diagram and wiring diagram:

image-20230509091609120

image-20230509091617551

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Test Code

You can open the code we provide:

Go to the folder KS3026 Keyestudio Raspberry Pi Pico Learning Kit Basic Edition\2. Windows System\2. C_Tutorial\2. Projects\Project 10：8×8 Dot-matrix Display\Project_10_8_8_Dot_Matrix_Display.

//**********************************************************************
/* 
 * Filename    : 8×8 Dot-matrix Display
 * Description : 8×8 Dot-matrix displays numbers from 0 to 9.
 * Auther      : http//www.keyestudio.com
*/
int R[] = {18,26,17,21,10,16,11,14};
int C[] = {22,12,13,19,15,20,27,28};

unsigned char data_0[8][8] =
{
{0,0,1,1,1,0,0,0},
{0,1,0,0,0,1,0,0},
{0,1,0,0,0,1,0,0},
{0,1,0,0,0,1,0,0},
{0,1,0,0,0,1,0,0},
{0,1,0,0,0,1,0,0},
{0,1,0,0,0,1,0,0},
{0,0,1,1,1,0,0,0}
};

unsigned char data_1[8][8] =
{
{0,0,0,0,1,0,0,0},
{0,0,0,1,1,0,0,0},
{0,0,0,0,1,0,0,0},
{0,0,0,0,1,0,0,0},
{0,0,0,0,1,0,0,0},
{0,0,0,0,1,0,0,0},
{0,0,0,0,1,0,0,0},
{0,0,0,1,1,1,0,0}
};

unsigned char data_2[8][8] =
{
{0,0,1,1,1,0,0,0},
{0,1,0,0,0,1,0,0},
{0,0,0,0,0,1,0,0},
{0,0,0,0,1,0,0,0},
{0,0,0,1,0,0,0,0},
{0,0,1,0,0,0,0,0},
{0,1,1,1,1,1,0,0},
{0,0,0,0,0,0,0,0}
};

unsigned char data_3[8][8] =
{
{0,0,1,1,1,1,0,0},
{0,0,0,0,0,1,0,0},
{0,0,0,0,0,1,0,0},
{0,0,1,1,1,1,0,0},
{0,0,0,0,0,1,0,0},
{0,0,0,0,0,1,0,0},
{0,0,1,1,1,1,0,0},
{0,0,0,0,0,0,0,0}
};

unsigned char data_4[8][8] =
{
{0,1,0,0,0,0,0,0},
{0,1,0,0,1,0,0,0},
{0,1,0,0,1,0,0,0},
{0,1,1,1,1,1,1,0},
{0,0,0,0,1,0,0,0},
{0,0,0,0,1,0,0,0},
{0,0,0,0,1,0,0,0},
{0,0,0,0,0,0,0,0}
};

unsigned char data_5[8][8] =
{
{0,1,0,0,0,0,0,0},
{0,1,1,1,1,1,0,0},
{0,1,0,0,0,0,0,0},
{0,1,1,1,1,1,0,0},
{0,0,0,0,0,1,0,0},
{0,0,0,0,0,1,0,0},
{0,1,1,1,1,1,0,0},
{0,0,0,0,0,0,0,0}
};

unsigned char data_6[8][8] =
{
{0,1,1,1,1,1,0,0},
{0,1,0,0,0,0,0,0},
{0,1,0,0,0,0,0,0},
{0,1,1,1,1,1,0,0},
{0,1,0,0,0,1,0,0},
{0,1,0,0,0,1,0,0},
{0,1,1,1,1,1,0,0},
{0,0,0,0,0,0,0,0}
};

unsigned char data_7[8][8] =
{
{0,0,0,0,0,0,0,0},
{0,1,1,1,1,1,0,0},
{0,0,0,0,0,1,0,0},
{0,0,0,0,1,0,0,0},
{0,0,0,1,0,0,0,0},
{0,0,1,0,0,0,0,0},
{0,1,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0}
};

unsigned char data_8[8][8] =
{
{0,1,1,1,1,1,0,0},
{0,1,0,0,0,1,0,0},
{0,1,0,0,0,1,0,0},
{0,1,1,1,1,1,0,0},
{0,1,0,0,0,1,0,0},
{0,1,0,0,0,1,0,0},
{0,1,1,1,1,1,0,0},
{0,0,0,0,0,0,0,0}
};

unsigned char data_9[8][8] =
{
{0,1,1,1,1,1,0,0},
{0,1,0,0,0,1,0,0},
{0,1,0,0,0,1,0,0},
{0,1,1,1,1,1,0,0},
{0,0,0,0,0,1,0,0},
{0,0,0,0,0,1,0,0},
{0,1,1,1,1,1,0,0},
{0,0,0,0,0,0,0,0}
};

void Display(unsigned char dat[8][8])
{
for(int c = 0; c<8;c++)
{
digitalWrite(C[c],LOW);
for(int r = 0;r<8;r++)
{
digitalWrite(R[r],dat[r][c]);
}
delay(1);
Clear();
}
}

void Clear()
{
for(int i = 0;i<8;i++)
{
digitalWrite(R[i],LOW);
digitalWrite(C[i],HIGH);
}
}

void setup(){
  for(int i = 0;i<8;i++)
  {
    pinMode(R[i],OUTPUT);
    pinMode(C[i],OUTPUT);
  }

}

void loop(){
  for (int i = 1; i <= 100; i = i + (1)) {
    Display(data_0);
  }
  for (int i = 1; i <= 100; i = i + (1)) {
    Display(data_1);
  }
  for (int i = 1; i <= 100; i = i + (1)) {
    Display(data_2);
  }
  for (int i = 1; i <= 100; i = i + (1)) {
    Display(data_3);
  }
  for (int i = 1; i <= 100; i = i + (1)) {
    Display(data_4);
  }
  for (int i = 1; i <= 100; i = i + (1)) {
    Display(data_5);
  }
  for (int i = 1; i <= 100; i = i + (1)) {
    Display(data_6);
  }
  for (int i = 1; i <= 100; i = i + (1)) {
    Display(data_7);
  }
  for (int i = 1; i <= 100; i = i + (1)) {
    Display(data_8);
  }
  for (int i = 1; i <= 100; i = i + (1)) {
    Display(data_9);
  }
}
//**********************************************************************

Before uploading Test Code to Raspberry Pi Pico, please check the configuration of Arduino IDE.

Click “Tools” to confirm that the board type and ports.

image-20230509091713721

Click image-20230509091728119 to upload the test code to the Raspberry Pi Pico board.

image-20230509091749858

image-20230509091759234

Test Result：

You will view the 8*8 dot matrix show the“❤”pattern.