Freenove Ultimate Starter Kit - Page 281

281
Chapter 27 Solder Circuit Board
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The following is the program code:
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#include <wiringPi.h>
#include <stdio.h>
#include <wiringShift.h>
#include <unistd.h>
#define dataPin 0 //DS Pin of 74HC595(Pin14)
#define latchPin 2 //ST_CP Pin of 74HC595(Pin12)
#define clockPin 3 //SH_CP Pin of 74HC595(Pin11)
//Define an array to save the pulse width of LED. Output the signal to the 8 adjacent
LEDs in order.
const int pluseWidth[]={0,0,0,0,0,0,0,0,64,32,16,8,4,2,1,0,0,0,0,0,0,0,0};
void outData(int8_t data){
digitalWrite(latchPin,LOW);
shiftOut(dataPin,clockPin,LSBFIRST,data);
digitalWrite(latchPin,HIGH);
}
int main(void)
{
int i,j,index; //index:current position in array pluseWidth
int moveSpeed = 100; //move speed delay, the greater, the slower
long lastMove; //Record the last time point of the move
if(wiringPiSetup() == -1){ //when initialize wiring failed, print message to screen
printf("setup wiringPi failed !");
return 1;
}
pinMode(dataPin,OUTPUT);
pinMode(latchPin,OUTPUT);
pinMode(clockPin,OUTPUT);
index = 0; //Starting from the array index 0
lastMove = millis(); //the start time
while(1){
if(millis() - lastMove > moveSpeed) { //speed control
lastMove = millis(); //Record the time point of the move
index++; //move to next
if(index > 15) index = 0; //index to 0
}
for(i=0;i<64;i++){ //The cycle of PWM is 64 cycles
int8_t data = 0; //This loop of output data
for(j=0;j<8;j++){ //Calculate the output state of this loop
if(i < pluseWidth[index+j]){ //Calculate the LED state according to
the pulse width
data |= 0x01<<j ; //Calculate the data
}