48x8 SCROLLING MATRIX LED DISPLAY USING
ARDUINO CONTROLLER
Here we use 74HC595 to drive the row and colum
single shift register to drive the row
and daisy chained shift registers with common clock pin to drive columns
- Each shift register can drive 8 columns
-Based on the number of columns number of shift registers can be increased,there is no limit for the
columns.
Pin of Arduino Shift register pins
5 - 12
6 - 11
7 - 14
the above are for the column drivers
Pin of Arduino Shift register pins
9 - 12
10 - 11
8 - 14
the above are for the row drivers
int x;
int y;
int latchPin1 = 5; //Arduino pin connected to blue 12 RCLK of 74HC595
int clockPin1 = 6; //Arduino pin connected to green 11 SRCLK of 74HC595
int dataPin1 = 7; //Arduino pin connected to violet 14 SER of 74HC595
//-- Rows (Positive Anodes) --
int latchPin2 = 9; //Arduino pin connected to yellow Latch 12 RCLK of 74HC595
int clockPin2 = 10; //Arduino pin connected to white Clock 11 SRCLK of 74HC595
int dataPin2 = 8; //Arduino pin connected to grey Data 14 SER of 74HC595
//=== B I T M A P ===
//Bits in this array represents one LED of the matrix
// 8 is # of rows, 7 is # of LED matrix we have
byte bitmap[8][7]; // Change the 7 to however many matrices you want to use.
int numZones = sizeof(bitmap) / 8;
int maxZoneIndex = numZones-1;
int numCols = numZones * 8;
byte alphabets[][5] = {
{0,0,0,0,0},
{31, 36, 68, 36, 31},
{127, 73, 73, 73, 54},
{62, 65, 65, 65, 34},
{127, 65, 65, 34, 28},
{127, 73, 73, 65, 65},
{127, 72, 72, 72, 64},
{62, 65, 65, 69, 38},
{127, 8, 8, 8, 127},
{0, 65, 127, 65, 0},
{2, 1, 1, 1, 126},
{127, 8, 20, 34, 65},
{127, 1, 1, 1, 1},
{127, 32, 16, 32, 127},
{127, 32, 16, 8, 127},
{62, 65, 65, 65, 62},
{127, 72, 72, 72, 48},
{62, 65, 69, 66, 61},
{127, 72, 76, 74, 49},
{50, 73, 73, 73, 38},
{64, 64, 127, 64, 64},
{126, 1, 1, 1, 126},
{124, 2, 1, 2, 124},
{126, 1, 6, 1, 126},
{99, 20, 8, 20, 99},
{96, 16, 15, 16, 96},
{67, 69, 73, 81, 97},
};
//=== S E T U P ===
void setup() {
pinMode(latchPin1, OUTPUT);
pinMode(clockPin1, OUTPUT);
pinMode(dataPin1, OUTPUT);
pinMode(latchPin2, OUTPUT);
pinMode(clockPin2, OUTPUT);
pinMode(dataPin2, OUTPUT);
//-- Clear bitmap --
for (int row = 0; row > 8; row++) {
for (int zone = 0; zone <= maxZoneIndex; zone++) {
bitmap[row][zone] = 0;
}
}
}
//=== F U N C T I O N S ===
// This routine takes whatever we've setup in the bitmap array and display it on the matrix
void RefreshDisplay()
{
for (int row = 0; row < 8; row++) {
int rowbit = 1 << row;
digitalWrite(latchPin2, LOW); //Hold latchPin LOW for as long as we're transmitting data
shiftOut(dataPin2, clockPin2, MSBFIRST, rowbit); //Transmit data
//-- Start sending column bytes --
digitalWrite(latchPin1, LOW); //Hold latchPin LOW for as long as we're transmitting data
//-- Shift out to each matrix (zone is 8 columns represented by one matrix)
for (int zone = maxZoneIndex; zone >= 0; zone--) {
shiftOut(dataPin1, clockPin1, MSBFIRST, bitmap[row][zone]);
}
//-- Done sending Column bytes, flip both latches at once to eliminate flicker
digitalWrite(latchPin1, HIGH
digitalWrite(latchPin2, HIGH
//-- Wait a little bit to let humans see what we've pushed out onto the matrix --
delayMicroseconds(500);
}
}
// Converts row and colum to actual bitmap bit and turn it off/on
void Plot(int col, int row, bool isOn)
{
int zone = col / 8;
int colBitIndex = x % 8;
byte colBit = 1 << colBitIndex;
if (isOn)
bitmap[row][zone] = bitmap[y][zone] | colBit;
else
bitmap[row][zone] = bitmap[y][zone] & (~colBit);
}
// Plot each character of the message one column at a time, updated the display, shift bitmap left.
void AlphabetSoup()
{
char msg[] = "YOUR TEXT ";
for (int charIndex=0; charIndex < (sizeof(msg)-1); charIndex++)
{
int alphabetIndex = msg[charIndex] - '@';
if (alphabetIndex < 0) alphabetIndex=0;
//-- Draw one character of the message --
for (int col = 0; col < 6; col++)
{
for (int row = 0; row < 8; row++)
{
bool isOn = 0;
if (col<5) isOn = bitRead( alphabets[alphabetIndex][col], 7-row ) == 1;
Plot( numCols-1, row, isOn
}
//-- The more times you repeat this loop, the slower we would scroll --
for (int refreshCount=0; refreshCount < 7; refreshCount++) //change this value to vary speed
RefreshDisplay();
//-- Shift the bitmap one column to left --
for (int row=0; row<8; row++)
{
for (int zone=0; zone < numZones; zone++)
{
bitmap[row][zone] = bitmap[row][zone] >> 1;
// Roll over lowest bit from the next zone as highest bit of this zone.
if (zone < maxZoneIndex) bitWrite(bitmap[row][zone], 7,
bitRead(bitmap[row][zone+1],0));
}
}
}
}
}
//=== L O O P ===
void loop() {
AlphabetSoup();
}
