Freenove Ultimate Starter Kit, Manual

Page: 216 / 286

Chapter 19 74HC595 & LED Matrix
216
www.freenove.com █
█ support@freenove.com
The second “for” cycle is used to display scrolling characters "0-F", totally 18*8=144 columns. Display the 0-
8 column, 1-9 column, 2-10 column...... 138-144 column in turn to achieve scrolling effect. The display of
each frame is repeated a certain number of times, and the more times the number of repetitions, the longer
the single frame display, the slower the rolling.
for ( k = 0 ; k < sizeof ( data )- 8 ; k ++){ //sizeof(data) total number of "0-F" columns
for ( j = 0 ; j < 20 ; j ++){// times of repeated displaying LEDMatrix in every frame,
the bigger the “j” , the longer the display time
x = 0x80 ; // Set the column information to start from the first column
for ( i = k ; i < 8 + k ; i ++){
digitalWrite ( latchPin , LOW );
shiftOut ( dataPin , clockPin ,M SBFIRST , data [ i ]);
shiftOut ( dataPin , clockPin , MSBFIRST ,~ x );
digitalWrite ( latchPin , HIGH );
x >>= 1 ;
delay ( 1 );
}
}
}