【树莓派】树莓派调光

一、树莓派非PWM引脚，模拟PWM调光

#include <stdio.h>
#include <stdlib.h>
#include <wiringPi.h>
#include <pthread.h>
unsigned int bedroom_brightness;
void *bedroom_brightness_set(void *arg)//线程函数
{
    	
	while(1){
      // 设置一个周期为1ms，占空比为60%
			//2引脚低电平时发光
			digitalWrite(2, LOW);
			delayMicroseconds(1000-(bedroom_brightness*100));
			//高电平时熄灭
			digitalWrite(2, HIGH);
			delayMicroseconds(bedroom_brightness*100);  // 微秒级延迟，0.4ms
// }
	}
}
void main(){
    
	pthread_t id;
	id = pthread_create(&id, NULL, bedroom_brightness_set, NULL);//创建线程
	
	wiringPiSetup();  //初始化硬件环境
	pinMode(2, OUTPUT);   
	while(1)
	{
    
		printf("brightness;");
		scanf("%d", &bedroom_brightness);//设定亮度，数值(0-10)
	}
}

二、树莓派PWM引脚调光

PS：仅支持PWM引脚，树莓派PWM引脚默认有GPIO1，其他参考引脚图

#include <wiringPi.h>
void bedroom_brightness_set(int *bedroom_brightness, int *bright_last)
{
    

	
	if(*bedroom_brightness < *bright_last)//调低亮度（下一次设定的亮度小于当前亮度）
	{
    
		for(*bright_last; *bedroom_brightness<*bright_last; --*bright_last)
		{
    
			pwmWrite(1, *bright_last);//向pwm中写入任意自己想要的值(默认0-1024)
			delay(1);
		}
		printf("亮度变低\n");
	}
	else if(*bedroom_brightness > *bright_last)//调高亮度（下一次设定的亮度大于当前亮度）
	{
    
		for(*bright_last; *bright_last<*bedroom_brightness; ++*bright_last)
		{
    
			pwmWrite(1, *bright_last);  //数值范围（0-1024）
			delay(1);
		}
		printf("亮度变高\n");
	}
	*bright_last = *bedroom_brightness;
}