any help please

Using Arduino Programming Questions
#1

i have been working on an 8x80 led matrix display. i have managed to get it to display text however i now want the text to be scrolling. any ideas on where i go from here with this code would be very much appreciated as i am completely stuck. Thanks.

int redData = 10;
int clockPin = 12; //clock
int latchPin = 11; //latch
int enablePin = 8;

//const int horizontalDisplay = 10;
//const int verticlaDisplay = 1;

byte data;
byte dataArray[8];
byte dataArray1[8];
byte dataArray2[8];
byte dataArray3[8];
byte dataArray4[8];
byte dataArray5[8];
byte dataArray6[8];
byte dataArray7[8];

void setup() {
// put your setup code here, to run once:

Serial.begin(9600);

dataArray[0] = 0xff;
dataArray[1] = 0xff;
dataArray[2] = 0xff;
dataArray[3] = 0xff; // O
dataArray[4] = 0xff;
dataArray[5] = 0xff;
dataArray[6] = 0xff;
dataArray[7] = 0xff;

//{0xff,0x81,0xbd,0xbd,0xbd,0xbd,0xbd,0x81}
dataArray1[0] = 0x81;
dataArray1[1] = 0xBD;
dataArray1[2] = 0xBD;
dataArray1[3] = 0xBD; // O
dataArray1[4] = 0xBD;
dataArray1[5] = 0xBD;
dataArray1[6] = 0x81;
dataArray1[7] = 0xFF;

//{0xff,0xbd,0xbd,0xbd,0x81,0xbd,0xbd,0xbd}
dataArray2[0] = 0xBD;
dataArray2[1] = 0xBD;
dataArray2[2] = 0xBD;
dataArray2[3] = 0x81;
dataArray2[4] = 0xBD; //H
dataArray2[5] = 0xBD;
dataArray2[6] = 0xBD;
dataArray2[7] = 0xFF;

//{0xff,0x81,0xbf,0xbf,0x81,0xbf,0xbf,0x81}
dataArray3[0] = 0x81;
dataArray3[1] = 0xBF;
dataArray3[2] = 0xBF;
dataArray3[3] = 0x81;
dataArray3[4] = 0xBF; //E
dataArray3[5] = 0xBF;
dataArray3[6] = 0x81;
dataArray3[7] = 0xFF;

//{0xbf,0xbf,0xbf,0xbf,0xbf,0xbf,0xbf,0x81}
dataArray4[0] = 0xBF;
dataArray4[1] = 0xBF;
dataArray4[2] = 0xBF;
dataArray4[3] = 0xBF;
dataArray4[4] = 0xBF; //L
dataArray4[5] = 0xBF;
dataArray4[6] = 0x81;
dataArray4[7] = 0xFF;

pinMode(enablePin, OUTPUT);
pinMode(clockPin, OUTPUT);
pinMode(redData, OUTPUT);
pinMode(latchPin, OUTPUT);

DDRC = DDRC | B11110000;
for (int i=0; i<8; i++){
PORTC = i<<4;

digitalWrite(enablePin, 0);

shiftOut(redData, clockPin, MSBFIRST, 0);
shiftOut(redData, clockPin, MSBFIRST, 0);
shiftOut(redData, clockPin, MSBFIRST, 0);
shiftOut(redData, clockPin, MSBFIRST, 0);
shiftOut(redData, clockPin, MSBFIRST, 0);
shiftOut(redData, clockPin, MSBFIRST, 0);
shiftOut(redData, clockPin, MSBFIRST, 0);
shiftOut(redData, clockPin, MSBFIRST, 0);
shiftOut(redData, clockPin, MSBFIRST, 0);
shiftOut(redData, clockPin, MSBFIRST, 0);

digitalWrite(enablePin, 1);
delay(1);
}

analogWrite(enablePin,255);
}

void loop() {
// put your main code here, to run repeatedly:

//for(int j=0; j<=7; j++) {
// digitalWrite(latchPin, LOW);
// digitalWrite(latchPin2, LOW);

for (int i=0; i<8; i++){

PORTC = i<<4;

digitalWrite(latchPin, LOW);

shiftOut(redData, clockPin, MSBFIRST, dataArray*);*
_ shiftOut(redData, clockPin, MSBFIRST, dataArray*);_
_ shiftOut(redData, clockPin, MSBFIRST, dataArray2);
shiftOut(redData, clockPin, MSBFIRST, dataArray3);
shiftOut(redData, clockPin, MSBFIRST, dataArray4);
shiftOut(redData, clockPin, MSBFIRST, dataArray4);
shiftOut(redData, clockPin, MSBFIRST, dataArray1);
shiftOut(redData, clockPin, MSBFIRST, dataArray);
shiftOut(redData, clockPin, MSBFIRST, dataArray);
shiftOut(redData, clockPin, MSBFIRST, dataArray);
digitalWrite(latchPin, HIGH);
delayMicroseconds(1);*_

}
}

#2 
    shiftOut(redData, clockPin, MSBFIRST, 0);
    shiftOut(redData, clockPin, MSBFIRST, 0);
    shiftOut(redData, clockPin, MSBFIRST, 0);
    shiftOut(redData, clockPin, MSBFIRST, 0);
    shiftOut(redData, clockPin, MSBFIRST, 0);
    shiftOut(redData, clockPin, MSBFIRST, 0);
    shiftOut(redData, clockPin, MSBFIRST, 0);
    shiftOut(redData, clockPin, MSBFIRST, 0);
    shiftOut(redData, clockPin, MSBFIRST, 0);
    shiftOut(redData, clockPin, MSBFIRST, 0);

Good thing you didn't have to do that 1000 times.

Get rid of the commented out code. Tell us what the code ACTUALLY does.

#3

the code is being used to display text on a 8x80 led Matrix, currently it is displaying the word "hello". Each of the data arrray are used to display an individual letter and is shifted out by this section of code below:

shiftOut(redData, clockPin, MSBFIRST, dataArray);
shiftOut(redData, clockPin, MSBFIRST, dataArray);
shiftOut(redData, clockPin, MSBFIRST, dataArray2);
shiftOut(redData, clockPin, MSBFIRST, dataArray3);
shiftOut(redData, clockPin, MSBFIRST, dataArray4);
shiftOut(redData, clockPin, MSBFIRST, dataArray4);
shiftOut(redData, clockPin, MSBFIRST, dataArray1);
shiftOut(redData, clockPin, MSBFIRST, dataArray);
shiftOut(redData, clockPin, MSBFIRST, dataArray);
shiftOut(redData, clockPin, MSBFIRST, dataArray);

each line above represents 1 8x8 led matrix and is displaying a 'H' on line 3, 'E' on line 4 etc.

#4

on line 3, 'E' on line 4 etc.

I can not picture how you get 7 plus lines on a 8 x 80 LED matrix. A picture is definitely in order.

If you want the text to be scrolling, you need to define whether that means left to right, top to bottom, right to left, or bottom to top. And, you need to not draw the same character in the same position every time through loop.

It would certainly be a lot easier to understand if you named the arrays to correspond to the letter that they represent. It would be a lot easier to change the code to display different text in different places if you had a 2D array with A in the 0 position of one dimension, B in the 1 position, etc.

#5