Hello Arduino enthusiast.
My current project is to build a WS2811 LED matrix. It scrolls a text continuously, which was previously entered in the serial monitor (via Bluetooth). If a new entry is made in the serial monitor, the old text should be deleted and the new text should now be scrolled permanently. With the approached sketch (not created by me) the old text is unfortunately not deleted when the new text is entered.
Can someone please help me to solve the problem?
Greetings, Bastian
Here is the code:
// scrolls data read from serial to matrix
// the following libraries are required for the sketch to work
#include <Adafruit_GFX.h>
#include <Adafruit_NeoMatrix.h>
#include <Adafruit_NeoPixel.h>
#define PIN 6
String readString; // creates the string scrolling text will be held in
// MATRIX DECLARATION:
// Parameter 1 = width of NeoPixel matrix
// Parameter 2 = height of matrix
// Parameter 3 = pin number (most are valid)
// Parameter 4 = matrix layout flags, add together as needed:
// NEO_MATRIX_TOP, NEO_MATRIX_BOTTOM, NEO_MATRIX_LEFT, NEO_MATRIX_RIGHT:
// Position of the FIRST LED in the matrix; pick two, e.g.
// NEO_MATRIX_TOP + NEO_MATRIX_LEFT for the top-left corner.
// NEO_MATRIX_ROWS, NEO_MATRIX_COLUMNS: LEDs are arranged in horizontal
// rows or in vertical columns, respectively; pick one or the other.
// NEO_MATRIX_PROGRESSIVE, NEO_MATRIX_ZIGZAG: all rows/columns proceed
// in the same order, or alternate lines reverse direction; pick one.
// See example below for these values in action.
// Parameter 5 = pixel type flags, add together as needed:
// NEO_KHZ800 800 KHz bitstream (most NeoPixel products w/WS2812 LEDs)
// NEO_KHZ400 400 KHz (classic 'v1' (not v2) FLORA pixels, WS2811 drivers)
// NEO_GRB Pixels are wired for GRB bitstream (most NeoPixel products)
// NEO_RGB Pixels are wired for RGB bitstream (v1 FLORA pixels, not v2)
// Example for NeoPixel Shield. In this application we'd like to use it
// as a 5x8 tall matrix, with the USB port positioned at the top of the
// Arduino. When held that way, the first pixel is at the top right, and
// lines are arranged in columns, progressive order. The shield uses
// 800 KHz (v2) pixels that expect GRB color data.
Adafruit_NeoMatrix matrix = Adafruit_NeoMatrix(16, 16, PIN,
NEO_MATRIX_TOP + NEO_MATRIX_LEFT +
NEO_MATRIX_COLUMNS + NEO_MATRIX_ZIGZAG,
NEO_GRB + NEO_KHZ800);
//sets up colors for scrolling text - in this sketch only the first one is used
const uint16_t colors[] =
{
matrix.Color(255, 0, 0), matrix.Color(0, 255, 0), matrix.Color(0, 0, 255)
};
void setup()
{
Serial.begin(9600); //turn on the serial connection
matrix.begin(); //initalize the matrix
matrix.setTextWrap(false);
matrix.setBrightness(40);
matrix.setTextColor(colors[0]);
}
int x = 16; //holds the width of the matrix for counting colums
int pass = 0; //used to calculate the number of characters read from the serial input
void loop ()
{
matrix.fillScreen(0); //clear the screen
matrix.setCursor(x, 0); //set the begining cursor position
serialtochar();
chartoscreen();
} //end loop
void serialtochar()
{
while (Serial.available()) //if serial data is available, run the loop
{
delay(10);
if (Serial.available() > 0) //if there is serial data continue
{
char c = Serial.read(); //read the next byte of data
readString += c; //append the data to the char variable readString
}
}
}
void chartoscreen()
{
if (readString.length() > 0) //if the number of bytes in readString are greater than 0
{
matrix.println(readString); //print the data in readString
pass = -abs(readString.length()); //set pass to the negative value of the number of characters
if(--x < pass * 6) //reserve 6 spaces for each character - continue looping until x = pass * 6
{
x = matrix.width(); //set x to the number of colums in the matrix
readString = ""; //set the data to blank
}
matrix.show(); //show the data stored
delay(70); //wait a bit - sets scrolling speed
}
}
