// 2-dimensional array of row pin numbers: const int row[8] = { 19, 18, 17, 16, 15, 14, 2, 3 }; // 2-dimensional array of column pin numbers: const int col[8] = { 4, 5, 6, 7, 8, 9, 10, 11 }; // 2-dimensional array of pixels: int pixels[8][8]; int count = 1000; char str[] = "FABCDEDCBA"; int strLen = sizeof(str); int ptrChar = 0; typedef bool charMapType[8][8]; const charMapType charBlank = { {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0} }; const charMapType heart0 = { {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 1, 1, 0, 0, 0}, {0, 0, 0, 1, 1, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0} }; const charMapType heart1 = { {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 1, 1, 0, 0, 0}, {0, 0, 1, 1, 1, 1, 0, 0}, {0, 0, 1, 1, 1, 1, 0, 0}, {0, 0, 0, 1, 1, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0} }; const charMapType heart2 = { {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 1, 1, 0, 0, 1, 1, 0}, {1, 1, 1, 1, 1, 1, 1, 1}, {1, 1, 1, 1, 1, 1, 1, 1}, {0, 1, 1, 1, 1, 1, 1, 0}, {0, 0, 1, 1, 1, 1, 0, 0}, {0, 0, 0, 1, 1, 0, 0, 0} }; const charMapType heart3 = { {0, 0, 0, 0, 0, 0, 0, 0}, {0, 1, 1, 0, 0, 1, 1, 0}, {1, 1, 1, 1, 1, 1, 1, 1}, {1, 1, 1, 1, 1, 1, 1, 1}, {0, 1, 1, 1, 1, 1, 1, 0}, {0, 0, 1, 1, 1, 1, 0, 0}, {0, 0, 0, 1, 1, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0} }; const charMapType heart4 = { {0, 1, 1, 0, 0, 1, 1, 0}, {1, 1, 1, 1, 1, 1, 1, 1}, {1, 1, 1, 1, 1, 1, 1, 1}, {0, 1, 1, 1, 1, 1, 1, 0}, {0, 0, 1, 1, 1, 1, 0, 0}, {0, 0, 0, 1, 1, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0} }; const charMapType *charMap[6] = {&heart0, &heart1, &heart2, &heart3, &heart4, &charBlank}; void setup() { // initialize the I/O pins as outputs // iterate over the pins: for (int thisPin = 0; thisPin < 8; thisPin++) { // initialize the output pins: pinMode(col[thisPin], OUTPUT); pinMode(row[thisPin], OUTPUT); // take the row pins (i.e. the cathodes) high to ensure that // the LEDS are off: digitalWrite(row[thisPin], HIGH); } //setupScreen(); setupChar(); } void loop() { // draw the screen: refreshScreen(); if(count-- == 0){ count = 1000; setupChar(); } } void setupChar(){ char c = str[ptrChar]; int offset = c - 'A'; const charMapType *cMap = charMap[offset]; //charMapType *cMap = &charDummy; for (int x = 0; x < 8; x++) { for (int y = 0; y < 8; y++) { bool v = (*cMap)[x][y]; if(v){ pixels[x][y] = LOW; }else{ pixels[x][y] = HIGH; } } } ptrChar++; if(ptrChar>=strLen-1){ ptrChar = 0; } } void refreshScreen() { // iterate over the cols (anodes): for (int thisCol = 0; thisCol < 8; thisCol++) { // take the col pin (anode) high: digitalWrite(col[thisCol], HIGH); // iterate over the rows (cathodes): for (int thisRow = 0; thisRow < 8; thisRow++) { // get the state of the current pixel; int thisPixel = pixels[thisRow][thisCol]; // when the col is HIGH and the row is LOW, // the LED where they meet turns on: digitalWrite(row[thisRow], thisPixel); // turn the pixel off: if (thisPixel == LOW) { digitalWrite(row[thisRow], HIGH); } } // take the col pin low to turn off the whole row: digitalWrite(col[thisCol], LOW); } }