Project 18 8*16 dot matrix-knob control
1.Project instruction
There are on-board button switches on Max board, we will combine button switch and 8*16 dot matrix to make an interactive display.
2.Project principle
The signal pins of two buttons are connected to D2 and D3. Press left button, 8 * 16 dot matrix shows“L”; press right button, 8 * 16 dot matrix shows“R”.
3.Project circuit

4.Project code
Note: before uploading the code, you need to import the library files; otherwise, the code upload will fail.
#include <Wire.h>
#include "Keyestudio_LEDBackpack.h"
#include "Keyestudio_GFX.h"
Keyestudio_8x16matrix matrix = Keyestudio_8x16matrix();
int K1=3;
int K2=2;
int x;
void setup()
{
matrix.begin(0x70); // pass in the address
pinMode(K1,INPUT);
pinMode(K2,INPUT);
matrix.drawCircle(3,8, 3, LED_ON);
matrix.writeDisplay(); // write the changes we just made to the display
}
void loop()
{
int K1_level=digitalRead(K1);
int K2_level=digitalRead(K2);
if(K1_level==0)
{
matrix.setTextSize(1);
matrix.setTextWrap(false); // we dont want text to wrap so it scrolls nicely
matrix.setTextColor(LED_ON);
matrix.setRotation(1);
matrix.clear();
matrix.setCursor(2,0);
matrix.print("L");
matrix.writeDisplay();
}
if(K2_level==0)
{
matrix.setTextSize(1);
matrix.setTextWrap(false); // we dont want text to wrap so it scrolls nicely
matrix.setTextColor(LED_ON);
matrix.setRotation(1);
matrix.clear();
matrix.setCursor(9,0);
matrix.print("R");
matrix.writeDisplay();
}
}