pwm_dev = (struct rt_device_pwm)rt_device_find(PWM_DEV_NAME); if (pwm_dev == RT_NULL) { rt_kprintf("pwm sample run failed! can't find %s device!n", PWM_DEV_NAME); return RT_ERROR; } /设置PWM周期和脉冲宽度默认值/ rt_pwm_set(pwm_dev, PWM_DEV_CHANNEL, period, pulse); /...
pwm_dev = (struct rt_device_pwm)rt_device_find(PWM_DEV_NAME); if (pwm_dev == RT_NULL) { rt_kprintf("pwm sample run failed!can't find %s device!n", PWM_DEV_NAME); return RT_ERROR; } /设置PWM周期和脉冲宽度默认值/ rt_pwm_set(pwm_dev, PWM_DEV_CHANNEL, period, pulse); /使...
PWM(Pulse Width Modulation , 脉冲宽度调制) 是一种对模拟信号电平进行数字编码的方法,通过不同频率的脉冲使用方波的占空比用来对一个具体模拟信号的电平进行编码,使输出端得到一系列幅值相等的脉冲,用这些脉冲来代替所需要波形的设备。 上图是一个简单的 PWM 原理示意图,假定定时器工作模式为向上计数,当计数值小于...
if (pwm_dev1 == RT_NULL) { rt_kprintf("pwm sample run failed! can't find %s device!\n", PWM_DEV_NAME); } rt_kprintf("pwm sample run ! find %s device!\n", PWM_DEV_NAME); /* 设置PWM周期和脉冲宽度 */ rt_pwm_set(pwm_dev1, PWM_DEV_CHANNEL1, period, pulse); /* 使能设...
STEP 1, open pwm driver framework support in the RT-Thread Settings file 打开我们的RT-Thread Settings file 找到组件下的设备并打开pwm开关; 2.2、sep2:设置宏定义 STEP 2, define macro related to the pwm such as #define BSP_USING_PWM1
通过如下函数设置 PWM 周期和占空比: rt_err_t rt_pwm_set(struct rt_device_pwm *device, int channel, rt_uint32_t period, rt_uint32_t pulse); PWM 的输出频率由周期时间 period 决定,例如周期时间为 0.5ms (毫秒),则 period 值为 500000ns(纳秒),输出频率为 2KHz,占空比为 pulse / period,puls...
25if(pwm_dev == RT_NULL) 26{ 27rt_kprintf("pwm sample run failed! can't find %s device!\n", PWM_DEV_NAME); 28returnRT_ERROR; 29} 30/* 设置PWM周期和脉冲宽度默认值 */ 31rt_pwm_set(pwm_dev, PWM_DEV_CHANNEL, period, pulse); ...
这里采用了PWM(ART-Pi默认的PWM5通道1)来输出脉冲信号控制步进电机的转动速度,下面是使用函数: 1intpwm_set(rt_uint32_tfre,rt_uint8_tduty_cycle) 2{ 3rt_uint32_tperiod =0; 4rt_uint32_tpulse =0; 5pwm_dev = (struct rt_device_pwm *)rt_device_find(PWM_DEV_NAME); ...
6.3.2 PWM控制RGB灯 这部分内容在前面的章节已经讲过了,这里就不讲了,代码如下: #include "led_app.h" #define THREAD_PRIORITY 7 #define THREAD_STACK_SIZE 512 #define THREAD_TIMESLICE 3 uint32_t pulse_pulse = 90000; #define PWM_DEV_NAME_R "t5pwm" /* PWM设备名称 */ ...
if (pwm_dev_b == RT_NULL) { rt_kprintf("pwm led b run failed! can't find %s device!\n", PWM_DEV_NAME_B); } /* 设置PWM周期和脉冲宽度默认值 */ rt_pwm_set(pwm_dev_r, PWM_DEV_CHANNEL_R, period, pulse_r); rt_pwm_set(pwm_dev_g, PWM_DEV_CHANNEL_G, period, pulse_g)...