Amal Mathew
Published © GPL3+

ATtiny LED Matrix Display Badge

An ATtiny85-based badge-size PCB that can display letters and numbers.

BeginnerFull instructions provided2 hours997

Things used in this project

Hardware components

ATtiny85
Microchip ATtiny85
×1
Coin Cell Battery CR2032
Coin Cell Battery CR2032
×1
3 mm LED: Green
3 mm LED: Green
Any Color as your Wish.
×20
CR2032 Coin Cell Holder
×1
8 pin DIP IC Socket
×1
Slide Switch
Slide Switch
×1
Resistor 100 ohm
Resistor 100 ohm
×5

Software apps and online services

Arduino IDE
Arduino IDE
KiCad
KiCad
Fusion 360
Autodesk Fusion 360

Hand tools and fabrication machines

Soldering iron (generic)
Soldering iron (generic)

Story

Read more

Custom parts and enclosures

DXF File

Schematics

Schematics

Code

ATtiny_LED_Matrix_Display_Badge

Arduino
left to right Scrolling
#define MAP_START      32

#define DISPLAY_WIDTH  4
#define DISPLAY_HEIGHT 5

// "pixels" per second
#define SPEED          12

// the text to display
#define DISPLAY_STRING "  ATTINY LED MATRIX DISPLAY BADGE    "





// maps characters to their 4x5 grid 
unsigned long characterMap[59];

// set up a character in the characterMap
void Chr(char theChar, unsigned long value) {
  characterMap[theChar - MAP_START] = value;
}

// The offset of our string in the display
int offset = 0;
unsigned long lastMillis = 0;
unsigned long currentMillis = 0;
unsigned int timeout;

char myString[] = DISPLAY_STRING;
int length = sizeof(myString);

// render the string on the given offset
void renderString(char *theString, int offset) {
  int index = 0;
  while (theString[index]) {
    renderCharacter(theString[index], offset - index * (DISPLAY_WIDTH + 1));
    index++;
  }
}

// render a character on the given offset
void renderCharacter(char theChar, int charOffset) {
  if (charOffset <= -DISPLAY_WIDTH || charOffset > DISPLAY_WIDTH) {
    // off the 'screen' nothing to do
    return;
  }

  unsigned long graphic = characterMap[theChar - MAP_START];

  for (byte y = 0; y < DISPLAY_HEIGHT; y++) {
    for (byte x = 0; x < DISPLAY_WIDTH; x++) {
      // 3 - x to reverse order
      setPixel(3 - x - charOffset, y, graphic & 0x1);
      graphic = graphic >> 1;
    }
  }
}

// light a pixel at the given coordinates
void setPixel(byte x, byte y, boolean ledStatus) {
  if (x >= 0 && x < DISPLAY_WIDTH) {
    if (y <= x) {
      x++;
    }
    setLed(y, x, ledStatus);
  }
}

// turn on the pins to light a LED
void setLed(byte vin, byte gnd, boolean ledStatus) {
  delay(1);
  pinMode(0, INPUT); 
  pinMode(1, INPUT); 
  pinMode(2, INPUT); 
  pinMode(3, INPUT); 
  pinMode(4, INPUT); 

  if(!ledStatus) return;

  pinMode(vin, OUTPUT);   
  pinMode(gnd, OUTPUT); 
  digitalWrite(vin, HIGH);
  digitalWrite(gnd, LOW); 
}

// runs at start
void setup() {
  // set up render map

  // Rows:   1---2---3---4---5---
  Chr('A', 0b10011001111110010110);
  Chr('B', 0b01111001011110010111);
  Chr('C', 0b11100001000100011110);
  Chr('D', 0b01111001100110010111);
  Chr('E', 0b11110001011100011111);
  Chr('F', 0b00010001011100011111);
  Chr('G', 0b01101001110100011110);
  Chr('H', 0b10011001111110011001);
  Chr('I', 0b11100100010001001110);
  Chr('J', 0b00100101010001001110);
  Chr('K', 0b10010101001101011001);
  Chr('L', 0b11110001000100010001);
  Chr('M', 0b10011001111111111001);
  Chr('N', 0b10011001110110111001);
  Chr('O', 0b01101001100110010110);
  Chr('P', 0b00010001011110010111);
  Chr('Q', 0b10000110110110010110);
  Chr('R', 0b10010101011110010111);
  Chr('S', 0b11111000111100011111);
  Chr('T', 0b01000100010001001110);
  Chr('U', 0b01101001100110011001);
  Chr('V', 0b00100101100110011001);
  Chr('W', 0b01101111111110011001);
  Chr('X', 0b10011001011010011001);
  Chr('Y', 0b00110100011010011001);
  Chr('Z', 0b11110010010010001111);
  Chr(' ', 0b00000000000000000000);
  Chr('1', 0b11100100010001100100);
  Chr('2', 0b11110001011010000111);
  Chr('3', 0b01111000011010000111);
  Chr('4', 0b01001111010101100100);
  Chr('5', 0b01111000011100011111);
  Chr('6', 0b01101001011100010110);
  Chr('7', 0b00010010010010001111);
  Chr('8', 0b01101001011010010110);
  Chr('9', 0b01101000111010010110);
  Chr('0', 0b01101001110110110110);

  // how long to wait between shifting the display
  timeout = 1000 / SPEED;
}

// loops continuously
void loop() {
  currentMillis = millis();

  renderString(myString, offset);

  if (currentMillis - lastMillis > timeout) {
    lastMillis = currentMillis;
    // shift string over one "pixel"
    offset++;
    // if it's past the length of the string, start over from the beginning
    if (offset > length * (DISPLAY_WIDTH + 1)) {
      offset = -DISPLAY_WIDTH;
    }
  }
}

ATtiny_LED_Matrix_Display_Badge

Arduino
Right to left Scrolling
#define MAP_START      32

#define DISPLAY_WIDTH  4
#define DISPLAY_HEIGHT 5

// "pixels" per second
#define SPEED          12       

// the text to display
#define DISPLAY_STRING "  ATTINY LED MATRIX DISPLAY BADGE    "





// maps characters to their 4x5 grid 
unsigned long characterMap[59];

// set up a character in the characterMap
void Chr(char theChar, unsigned long value) {
  characterMap[theChar - MAP_START] = value;
}

// The offset of our string in the display
int offset = 0;
unsigned long lastMillis = 0;
unsigned long currentMillis = 0;
unsigned int timeout;

char myString[] = DISPLAY_STRING;
int length = sizeof(myString);

// render the string on the given offset
void renderString(char *theString, int offset) {
  int index = 0;
  while (theString[index]) {
    renderCharacter(theString[index], offset - index * (DISPLAY_WIDTH + 1));
    index++;
  }
}

// render a character on the given offset
void renderCharacter(char theChar, int charOffset) {
  if (charOffset <= -DISPLAY_WIDTH || charOffset > DISPLAY_WIDTH) {
    // off the 'screen' nothing to do
    return;
  }

  unsigned long graphic = characterMap[theChar - MAP_START];

  for (byte y = 0; y < DISPLAY_HEIGHT; y++) {
    for (byte x = 0; x < DISPLAY_WIDTH; x++) {
      
      setPixel(3 - x + charOffset, y, graphic & 0x1);
      graphic = graphic >> 1;
    }
  }
}

// light a pixel at the given coordinates
void setPixel(byte x, byte y, boolean ledStatus) {
  if (x >= 0 && x < DISPLAY_WIDTH) {
    if (y <= x) {
      x++;
    }
    setLed(y, x, ledStatus);
  }
}

// turn on the pins to light a LED
void setLed(byte vin, byte gnd, boolean ledStatus) {
  delay(1);
  pinMode(0, INPUT); 
  pinMode(1, INPUT); 
  pinMode(2, INPUT); 
  pinMode(3, INPUT); 
  pinMode(4, INPUT); 

  if(!ledStatus) return;

  pinMode(vin, OUTPUT);   
  pinMode(gnd, OUTPUT); 
  digitalWrite(vin, HIGH);
  digitalWrite(gnd, LOW); 
}

// runs at start
void setup() {
  // set up render map

  // Rows:   1---2---3---4---5---
  Chr('A', 0b10011001111110010110);
  Chr('B', 0b01111001011110010111);
  Chr('C', 0b11100001000100011110);
  Chr('D', 0b01111001100110010111);
  Chr('E', 0b11110001011100011111);
  Chr('F', 0b00010001011100011111);
  Chr('G', 0b01101001110100011110);
  Chr('H', 0b10011001111110011001);
  Chr('I', 0b11100100010001001110);
  Chr('J', 0b00100101010001001110);
  Chr('K', 0b10010101001101011001);
  Chr('L', 0b11110001000100010001);
  Chr('M', 0b10011001111111111001);
  Chr('N', 0b10011001110110111001);
  Chr('O', 0b01101001100110010110);
  Chr('P', 0b00010001011110010111);
  Chr('Q', 0b10000110110110010110);
  Chr('R', 0b10010101011110010111);
  Chr('S', 0b11111000111100011111);
  Chr('T', 0b01000100010001001110);
  Chr('U', 0b01101001100110011001);
  Chr('V', 0b00100101100110011001);
  Chr('W', 0b01101111111110011001);
  Chr('X', 0b10011001011010011001);
  Chr('Y', 0b00110100011010011001);
  Chr('Z', 0b11110010010010001111);
  Chr(' ', 0b00000000000000000000);
  Chr('1', 0b11100100010001100100);
  Chr('2', 0b11110001011010000111);
  Chr('3', 0b01111000011010000111);
  Chr('4', 0b01001111010101100100);
  Chr('5', 0b01111000011100011111);
  Chr('6', 0b01101001011100010110);
  Chr('7', 0b00010010010010001111);
  Chr('8', 0b01101001011010010110);
  Chr('9', 0b01101000111010010110);
  Chr('0', 0b01101001110110110110);

  // how long to wait between shifting the display
  timeout = 1000 / SPEED;
}

// loops continuously
void loop() {
  currentMillis = millis();

  renderString(myString, offset);

  if (currentMillis - lastMillis > timeout) {
    lastMillis = currentMillis;
    // shift string over one "pixel"
    offset++;
    // if it's past the length of the string, start over from the beginning
    if (offset > length * (DISPLAY_WIDTH + 1)) {
      offset = -DISPLAY_WIDTH;
    }
  }
}

Credits

Amal Mathew

Amal Mathew

12 projects • 47 followers
Maker | Open source ❤️| Engineer 👉🏽Technology for the Sake of Humanity

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