### Project 17 8*16 dot matrix-display images

**1.Project instruction**

A large number of display devices, like cellphone, computer screen and advertisement board, are made of tiny light-emitting unit. The 8*16 dot matrix aren’t able to show exquisite and high pixel pictures but some cute and customized heart-shape picture, smiley face and so on, even though consisting of 128 pcs light-emitting units.

**2.Project Principle**

- Introduction for Modulus Tool
- The online version of dot matrix modulus tool:
- http://dotmatrixtool.com/#

![](media/image-20260127152853764.png)

The dot matrix is 8*16 in this project, thereby, set the height to 8, width to 16, as shown below.

![](media/image-20260127152913452.png)

![](media/image-20260127153008981.png)

![](media/image-20260127153015077.png)

As same as dot matrix on Max board

Click Byte order to select “column major”

![](media/image-20260127153048222.png)

Tap endian to set little endian(lsb)

![](media/image-20260127153104654.png)

Then we draw the pattern we need.

![](media/image-20260127153115203.png)

Click generate to get hexadecimal code.

![](media/image-20260127153126858.png)

```
0x00, 0x04, 0x02, 0x02, 0x04, 0x20, 0x40, 0x40, 0x40, 0x40, 0x20, 0x04, 0x02, 0x02, 0x04, 0x00};
```

Move the above hexadecimal code into the code of the below program.

**3.Project circuit**

![](media/image-20260127153223581.png)

**4.Project code**

```c
#include <Wire.h>
#include "Keyestudio_LEDBackpack.h"
#include "Keyestudio_GFX.h"
Keyestudio_8x16matrix matrix = Keyestudio_8x16matrix();

void setup() 
{
 matrix.begin(0x70);  // pass in the address
}

static const uint8_t PROGMEM
smile_bmp[] ={ 0x00, 0x04, 0x02, 0x02, 0x04, 0x20, 0x40, 0x40, 0x40, 0x40, 0x20, 0x04, 0x02, 0x02, 0x04, 0x00};

void loop() 
{
  //matrix.setRotation(1);
  matrix.clear();
  matrix.drawBitmap(0, 0, smile_bmp, 8, 16, LED_ON);
  matrix.writeDisplay();
  delay(1000);
}
```