PSoc62™开发板之PWM呼吸灯

实验目的

利用PWM动态调节输出功率达到控制LED呼吸变化的效果

实验准备

PSoc62™开发板（开发板已经板载LED）

板载资源

板载有多少pwm

创建工程例程，在libraries/HAL_Drivers/drv_pwm.h中查看BSP支持的pwm数量及对应的GPIO，可以看到一共有8路pwm

/** Copyright (c) 2006-2023, RT-Thread Development Team** SPDX-License-Identifier: Apache-2.0** Change Logs:* Date           Author       Notes* 2022-07-13     Rbb666       first version*/#ifndef __PWM_CONFIG_H__
#define __PWM_CONFIG_H__#include <rtthread.h>
#include <board.h>#ifdef __cplusplus
extern "C"
{
#endif#define MAX_PERIOD 65535#ifdef BSP_USING_PWM0
#ifndef PWM0_CH0_PORT0_CONFIG
#define PWM0_CH0_PORT0_CONFIG       \{                               \.name = "pwm0",             \.channel = 0,               \.gpio = GET_PIN(0, 0),      \}
#endif /* PWM0_CH7_PORT2_CONFIG */#ifndef PWM0_CH7_PORT2_CONFIG
#define PWM0_CH7_PORT2_CONFIG       \{                               \.name = "pwm0",             \.channel = 7,               \.gpio = GET_PIN(2, 2),      \}
#endif /* PWM0_CH7_PORT2_CONFIG */#ifndef PWM0_CH7_PORT5_CONFIG
#define PWM0_CH7_PORT5_CONFIG       \{                               \.name = "pwm0",             \.channel = 7,               \.gpio = GET_PIN(5, 6),      \}
#endif /* PWM0_CH7_PORT5_CONFIG */#ifndef PWM0_CH7_PORT7_CONFIG
#define PWM0_CH7_PORT7_CONFIG       \{                               \.name = "pwm0",             \.channel = 7,               \.gpio = GET_PIN(7, 7),      \}
#endif /* PWM0_CH7_PORT7_CONFIG */#ifndef PWM0_CH7_PORT9_CONFIG
#define PWM0_CH7_PORT9_CONFIG       \{                               \.name = "pwm0",             \.channel = 7,               \.gpio = GET_PIN(9, 4),      \}
#endif /* PWM0_CH7_PORT9_CONFIG */#ifndef PWM0_CH7_PORT10_CONFIG
#define PWM0_CH7_PORT10_CONFIG      \{                               \.name = "pwm0",             \.channel = 7,               \.gpio = GET_PIN(10, 2),     \}
#endif /* PWM0_CH7_PORT10_CONFIG */#ifndef PWM0_CH7_PORT12_CONFIG
#define PWM0_CH7_PORT12_CONFIG      \{                               \.name = "pwm0",             \.channel = 7,               \.gpio = GET_PIN(12, 6),     \}
#endif /* PWM0_CH7_PORT12_CONFIG */#ifndef PWM0_CH3_PORT13_CONFIG
#define PWM0_CH3_PORT13_CONFIG      \{                               \.name = "pwm0",             \.channel = 3,               \.gpio = GET_PIN(13, 7),     \}
#endif /* PWM0_CH3_PORT13_CONFIG */
#endif /* BSP_USING_PWM0 */#ifdef __cplusplus
}
#endif#endif

pwm IO资源

编号	channel	gpio
pwm0	0	P0.0
pwm0	7	P2.2
pwm0	7	P5.6
pwm0	7	P7.7
pwm0	7	P9.4
pwm0	7	P10.2
pwm0	7	P12.6
pwm0	3	P13.7

电路图

在这里插入图片描述

这次实验用到的是pwm0 channel0，对应P0.0，也就是之前实验用的MCU_USER_LED1

使能PWM

在创建的RT-Thread串口工程中打开RT-Thread Settings，点击右边的箭头<<进入详细页，使用前先使能pwm0，如下图所示

在这里插入图片描述

程序设计

编码实现

#include <rtthread.h>
#include <rtdevice.h>#include <rtthread.h>
#include "board.h"
#include <rtdevice.h>#define PWM_LED_DEV     "pwm0"
#define PWM_CHANNEL     0int main(void)
{struct rt_device_pwm *pwm_dev = RT_NULL;rt_uint32_t period, pulse, up;int gap = 2000;int sec = 5;period = 500000;up = 1;pulse = 0;pwm_dev = (struct rt_device_pwm *)rt_device_find(PWM_LED_DEV);if (pwm_dev == RT_NULL){rt_kprintf("pwm device (%s) not found!\n", PWM_LED_DEV);return RT_ERROR;}rt_pwm_set(pwm_dev, PWM_CHANNEL, period, pulse);rt_pwm_enable(pwm_dev, PWM_CHANNEL);while (1){rt_thread_mdelay(sec);if (up){pulse += gap;}else{pulse -= gap;}if (pulse >= period){up = 0;}if (0 >= pulse){up = 1;}rt_pwm_set(pwm_dev, PWM_CHANNEL, period, pulse);}
}