Coolpi PWM

[macthree]

任何人都可以解释如何在 coolpi 上使用 PWM 吗？

[大法师]

@macthree 有部分GPIO支持硬件PWM功能，当然也可以用GPIO模拟PWM功能。

https://www.cool-pi.com/topic/80/coolpi-4b硬件扩展五-pwm

[macthree]

@大法师

使用 raspberry pi wiring.h 需要包含访问 PWM，如下所示.
coolpi 需要包括什么？

C Program

/*
Change the Intensity of LED using PWM on Raspberry Pi
http://www.electronicwings.com
*/

#include <wiringPi.h>

#include <stdio.h>
#include <stdlib.h>

const int PWM_pin = 1; /* GPIO 1 as per WiringPi, GPIO18 as per BCM */

int main (void)
{
int intensity ;

if (wiringPiSetup () == -1)
exit (1) ;

pinMode (PWM_pin, PWM_OUTPUT) ; /* set PWM pin as output */

while (1)
{

for (intensity = 0 ; intensity < 1024 ; ++intensity)
{
  pwmWrite (PWM_pin, intensity) ;	/* provide PWM value for duty cycle */
  delay (1) ;
}
delay(1);

for (intensity = 1023 ; intensity >= 0 ; --intensity)
{
  pwmWrite (PWM_pin, intensity) ;
  delay (1) ;
}
delay(1);

}
}

[大法师]

@macthree
这是软PWM，需要重写封装WiringPi