Month: January 2019

8×64 LED Display

This LED display allows you to send text from your mobile phone via Bluetooth. It’s ideal for placing in a shop window or displaying messages to drivers behind you in traffic.

Demo Video:

The Code:

#include <SPI.h>
#include <Adafruit_GFX.h>
#include <Max72xxPanel.h>

int pinCS = 10; // Attach CS to this pin, DIN to MOSI and CLK to SCK (cf http://arduino.cc/en/Reference/SPI )
int numberOfHorizontalDisplays = 1;
int numberOfVerticalDisplays = 8;

Max72xxPanel matrix = Max72xxPanel(pinCS, numberOfHorizontalDisplays, numberOfVerticalDisplays);

String tape = ” Dikkat “;
int wait = 70; // In milliseconds

int spacer = 1;
int width = 5 + spacer; // The font width is 5 pixels
String serialResponse = “”;
char sz[] = ” “;

void setup() {
matrix.setRotation(matrix.getRotation()+3); //1 – 90 2 – 180 3 – 270
matrix.setIntensity(15); // Use a value between 0 and 15 for brightness

//Clear screen
matrix.fillScreen(LOW);
matrix.write();

Serial.begin(9600);
}

void loop() {

if ( Serial.available()) {
serialResponse = Serial.readStringUntil(‘\r\n’);

if(serialResponse.length() > 1){
// Convert from String Object to String.
char buf[sizeof(sz)];
serialResponse.toCharArray(buf, sizeof(buf));
char *p = buf;
char *str;
while ((str = strtok_r(p, ” “, &p)) != NULL) // delimiter is the space
{
writeText(str, true);
delay(1000);
matrix.fillScreen(LOW);
matrix.write();
delay(400);
writeText(str, true);
delay(1000);
matrix.fillScreen(LOW);
matrix.write();
delay(400);
writeText(str, true);
delay(1000);
matrix.fillScreen(LOW);
matrix.write();
delay(500);
}
}
}
}

void writeText(String str, bool center)
{
int x = 0;
if(center)
{
x = ((int)matrix.width() – (int)(str.length() * width)) / 2;
if(x < 0){
x = 0;
}
}
int y = (matrix.height() – 8) / 2; // center the text vertically
matrix.fillScreen(LOW);
int letter = 0;
while (letter < str.length()) {
matrix.drawChar(x, y, str[letter], HIGH, LOW, 1);

letter++;
x += width;
}

matrix.write(); // Send bitmap to display
}

 

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You can also download the AppInventor application file for Android phones from the link below:

LCDTexter