目录
- API (机翻)
- 函数
- 上机实战
- 配置引脚
- PWM初始化，实现简易呼吸灯的效果
- 实验结果
- 完整代码
- myPWM.c
- myPWM.h
- myTask.c
- myTask.h
- main.c
- main.h
平台：Code Composer Studio 10.4.0
MSP432P401R SimpleLink™ 微控制器 LaunchPad™ 开发套件
(MSP-EXP432P401R)
API (机翻)
PWM API 官方手册
函数
void PWM_close (PWM_Handle handle)
函数关闭由PWM句柄指定的PWM实例int_fast16_t PWM_control (PWM_Handle handle, uint_fast16_t cmd, void *arg)
函数在给定的PWM_Handle上执行特定的实现特性void PWM_init (void)
这个函数初始化PWM模块PWM_Handle PWM_open (uint_least8_t index, PWM_Params *params)
这个函数打开一个给定的PWM实例，并将周期、负载和空闲电平设置为params参数中指定的值void PWM_Params_init (PWM_Params *params)
函数将PWM_Params结构初始化为默认值int_fast16_t PWM_setDuty (PWM_Handle handle, uint32_t duty)
命令功能设置指定PWM句柄的占空比。PWM实例在主动高电平输出模式(非开漏)下运行;
0%代表低电平，100%代表高电平。这个API可以被调用，而PWM正在运行&负载必须总是
低于或等于周期。如果调用该函数时发生错误，PWM占空比将保持不变int_fast16_t PWM_setPeriod (PWM_Handle handle, uint32_t period)
设置指定PWM句柄的周期。这个API可以在PWM运行时调用。周期必须总是大于等于占空比。
如果调用该函数时发生错误，PWM周期将保持不变int_fast16_t PWM_setDutyAndPeriod (PWM_Handle handle, uint32_t duty, uint32_t period)
设置指定PWM句柄的周期和占空比。这个API必须在PWM运行时调用。周期必须总是大于占空比。
如果在调用函数时发生错误，周期和占空比将保持不变void PWM_start (PWM_Handle handle)
以当前设置启动指定的PWM句柄void PWM_stop (PWM_Handle handle)
能停止指定的PWM句柄。输出将被设置为PWM_open()中的参数指定的空闲级别
上机实战
配置引脚
LED1，用于指示单片机正常工作
PWM输出引脚
PWM初始化，实现简易呼吸灯的效果
/** ======== mainThread ========*/
void *mainThread(void *arg0)
{float LED2_G_Duty = 0;int8_t LED2_DIR = 1;My_Task_Init(LED_Task, 1, 1024);My_PWM_Hz_Init(&hpwm1, PWM_1, 1000);while(1){if(LED2_G_Duty >= 100)LED2_DIR = -1;else if(LED2_G_Duty <= 0)LED2_DIR = 1;LED2_G_Duty += LED2_DIR * 0.5;if(LED2_G_Duty < 0)LED2_G_Duty = 0;else if(LED2_G_Duty > 100)LED2_G_Duty = 100;My_PWM_setDuty(&hpwm1, LED2_G_Duty);usleep(1000);}
}
实验结果
完整代码
myPWM.c
/** myPWM.c** Created on: 2021年8月2日* Author: Royic*/
// Import PWM Driver definitions#include "./inc/myPWM.h"PWM_Handle hpwm1;void My_PWM_Hz_Init(PWM_Handle *hpwm, uint_least8_t index, uint32_t Frequency)
{PWM_Params pwmParams;// Initialize the PWM driver.PWM_init();// Initialize the PWM parametersPWM_Params_init(&pwmParams);pwmParams.idleLevel = PWM_IDLE_LOW; // Output low when PWM is not runningpwmParams.periodUnits = PWM_PERIOD_HZ; // Period is in HzpwmParams.periodValue = Frequency; // Frequency HzpwmParams.dutyUnits = PWM_DUTY_FRACTION; // Duty is in fractional percentagepwmParams.dutyValue = 0; // 0% initial duty cycle// Open the PWM instance*hpwm = PWM_open(index, &pwmParams);if (*hpwm == NULL){// PWM_open() failedwhile (1);}PWM_start(*hpwm); // start PWM with 0% duty cycle
}inline void My_PWM_setDuty(PWM_Handle *hpwm, float Percentage)
{PWM_setDuty(*hpwm, (uint32_t) (PWM_DUTY_FRACTION_MAX / 100. * Percentage)); // set duty cycle to Duty_Cycle%
}
myPWM.h
/** myTask.h** Created on: 2021年8月2日* Author: Royic*/#ifndef INC_MYTASK_H_
#define INC_MYTASK_H_#include "./inc/main.h"void *mainThread(void *arg0);
void My_Task_Init(void *(*startroutine)(void *), int priority, size_t stacksize);void *LED_Task(void *arg0);#endif /* INC_MYTASK_H_ */
myTask.c
/** myTask.c** Created on: 2021年8月2日* Author: Royic*//* POSIX Header files */
#include <pthread.h>/* RTOS header files */
#include <ti/sysbios/BIOS.h>#include "./inc/myTask.h"/* Driver Header files */
#include <ti/drivers/GPIO.h>void My_Task_Init(void *(*startroutine)(void *), int priority, size_t stacksize)
{pthread_t thread;pthread_attr_t attrs;struct sched_param priParam;int retc;/* Initialize the attributes structure with default values */pthread_attr_init(&attrs);/* Set priority, detach state, and stack size attributes */priParam.sched_priority = priority;retc = pthread_attr_setschedparam(&attrs, &priParam);retc |= pthread_attr_setdetachstate(&attrs, PTHREAD_CREATE_DETACHED);retc |= pthread_attr_setstacksize(&attrs, stacksize);if (retc != 0){/* failed to set attributes */while (1){}}retc = pthread_create(&thread, &attrs, startroutine, NULL);if (retc != 0){/* pthread_create() failed */while (1){}}
}void *LED_Task(void *arg0)
{while(1){GPIO_toggle(LED1);sleep(1);}
}myTask.h
/** myTask.h** Created on: 2021年8月2日* Author: Royic*/#ifndef INC_MYTASK_H_
#define INC_MYTASK_H_#include "./inc/main.h"void *mainThread(void *arg0);
void My_Task_Init(void *(*startroutine)(void *), int priority, size_t stacksize);void *LED_Task(void *arg0);#endif /* INC_MYTASK_H_ */main.c
/** ======== main_tirtos.c ========*/#include "./inc/main.h"/* POSIX Header files */
#include <pthread.h>/* RTOS header files */
#include <ti/sysbios/BIOS.h>/* Driver configuration */
#include <ti/drivers/Board.h>
#include <ti/drivers/GPIO.h>#include "./inc/myTask.h"#include "./inc/myPWM.h"/** ======== main ========*/
int main(void)
{/* Call driver init functions */Board_init();GPIO_init();My_Task_Init(mainThread, 1, 1024);BIOS_start();return (0);
}/** ======== mainThread ========*/
void *mainThread(void *arg0)
{float LED2_G_Duty = 0;int8_t LED2_DIR = 1;My_Task_Init(LED_Task, 1, 1024);My_PWM_Hz_Init(&hpwm1, PWM_1, 1000);while(1){if(LED2_G_Duty >= 100)LED2_DIR = -1;else if(LED2_G_Duty <= 0)LED2_DIR = 1;LED2_G_Duty += LED2_DIR * 0.5;if(LED2_G_Duty < 0)LED2_G_Duty = 0;else if(LED2_G_Duty > 100)LED2_G_Duty = 100;My_PWM_setDuty(&hpwm1, LED2_G_Duty);usleep(1000);}
}main.h
/** main.h** Created on: 2021年8月2日* Author: Royic*/#ifndef INC_MAIN_H_
#define INC_MAIN_H_/* For usleep() */
#include <unistd.h>
#include <stdint.h>
#include <stddef.h>/* Driver configuration */
#include "ti_drivers_config.h"#endif /* INC_MAIN_H_ */
)
