[嵌入式]2022/9/21——基于stm32mp157a的pwm练习

本次实验使用pwm激活风扇、蜂鸣器、马达三个组件。?

PWM:脉冲宽度调制定时器，通过PWM产生一个方波，作为震荡源驱动蜂鸣器等器件正常工作

查询芯片手册可知蜂鸣器：TIM4_CH1---->PB6? ?风扇：TIM1_CH1---->PE9??马达：TIM16_CH1---->PF6? ??

一、pwm.h——头文件的包络和函数的声明

#ifndef __PWM_H__
#define __PWM_H__

#include "stm32mp1xx_gpio.h"
#include "stm32mp1xx_rcc.h"
#include "stm32mp1xx_tim.h"
/******蜂鸣器******/
//RCC章节初始化
void fm_rcc_init();
//GPIO章节初始化
void fm_gpio_init();
//TIM4章节初始化
void fm_tim4_init();
/******马达******/
//RCC章节初始化
void md_rcc_init();
//GPIO章节初始化
void md_gpio_init();
//TIM16章节初始化
void md_tim16_init();
/******风扇******/
//RCC章节初始化
void fs_rcc_init();
//GPIO章节初始化
void fs_gpio_init();
//TIM1章节初始化
void fs_tim1_init();


#endif

二、pwm.c——功能函数的声明（以蜂鸣器为例）

rcc章节的初始化

void fm_rcc_init()
{
	//GPIOB使能
	RCC->MP_AHB4ENSETR |= (0x1 << 1);
	//TIM4EN使能
	RCC->MP_APB1ENSETR |= (0x1 << 2);
}

GPIO章节初始化——设置引脚的复用功能

void fm_gpio_init()
{
	//设置PB6引脚为复用模式
	GPIOB->MODER &= (~(0x3 <<12));
	GPIOB->MODER |= (0x1 << 13);
	//设置PB6引脚功能为AF2--->TIM4_CH1
	GPIOB->AFRL &= (~(0xf << 24));
	GPIOB->AFRL |= (0x1 << 25);
}

TIM4章节初始化

?

1）配置TIM4_PSC寄存器

	TIM4->PSC &= (~(0xffff << 0));
	TIM4->PSC |= (0xD0 << 0);

2）配置TIM4_ARR寄存器——影响周期和频率

	TIM4->ARR &= (~(0xffff << 0));
	TIM4->ARR |= (0x3E8 << 0);

3）配置TIM4_CCR1寄存器

	TIM4->CCR1 &= (~(0xffff << 0));
	TIM4->CCR1 |= (0x12C << 0);

4）配置TIM4_CCMR1寄存器

	//1.设置为pwm1模式
	TIM4->CCMR1 &= (~(0x1 << 16));
	TIM4->CCMR1 &= (~(0x1 << 4));
	TIM4->CCMR1 |= (0x3 << 5);
	//2.设置预加载使能
	TIM4->CCMR1 |= (0x1 << 3);
	//3.设置为输出模式
	TIM4->CCMR1 &= (~(0x3 << 0));

5）配置TIM4_CCER寄存器

	//1.配置起始状态高电平
	TIM4->CCER &= (~(0x1 << 1));
	//2.配置输出使能
	TIM4->CCER |= (0x1 << 0);

6）配置tim计算器方式--TIM4_CR

	//1.自动重载计数器预加载使能
	TIM4->CR1 |= (0x1 << 7);
	//2.设置边沿对齐模式
	TIM4->CR1 &= (~(0x3 << 5));
	//3.设置递减计数器
	TIM4->CR1 |= (0x1 << 4);
	//4.设置计数器使能
	TIM4->CR1 |= (0x1 << 0);

马达和风扇的配置与蜂鸣器相似，但需要将复用事件改为AF1(0b0001)，并加入BDTR寄存器的配置

	//配置TIM16_BDTR寄存器
	TIM16->BDTR |= (0x1 << 15);

完整代码

#include "pwm.h"

//蜂鸣器RCC章节初始化
void fm_rcc_init()
{
	//GPIOB使能
	RCC->MP_AHB4ENSETR |= (0x1 << 1);
	//TIM4EN使能
	RCC->MP_APB1ENSETR |= (0x1 << 2);
}

//蜂鸣器GPIO章节初始化
void fm_gpio_init()
{
	//设置PB6引脚为复用模式
	GPIOB->MODER &= (~(0x3 <<12));
	GPIOB->MODER |= (0x1 << 13);
	//设置PB6引脚功能为AF2--->TIM4_CH1
	GPIOB->AFRL &= (~(0xf << 24));
	GPIOB->AFRL |= (0x1 << 25);
}

//蜂鸣器TIM4章节初始化
void fm_tim4_init()
{
	//配置TIM4_PSC寄存器
	TIM4->PSC &= (~(0xffff << 0));
	TIM4->PSC |= (0xD0 << 0);

	//配置TIM4_ARR寄存器——影响周期和频率
	TIM4->ARR &= (~(0xffff << 0));
	TIM4->ARR |= (0x3E8 << 0);

	//配置TIM4_CCR1寄存器
	TIM4->CCR1 &= (~(0xffff << 0));
	TIM4->CCR1 |= (0x12C << 0);

	//配置TIM4_CCMR1寄存器
	//1.设置为pwm1模式
	TIM4->CCMR1 &= (~(0x1 << 16));
	TIM4->CCMR1 &= (~(0x1 << 4));
	TIM4->CCMR1 |= (0x3 << 5);
	//2.设置预加载使能
	TIM4->CCMR1 |= (0x1 << 3);
	//3.设置为输出模式
	TIM4->CCMR1 &= (~(0x3 << 0));

	//配置TIM4_CCER寄存器
	//1.配置起始状态高电平
	TIM4->CCER &= (~(0x1 << 1));
	//2.配置输出使能
	TIM4->CCER |= (0x1 << 0);

	//配置tim计算器方式--TIM4_CR1
	//1.自动重载计数器预加载使能
	TIM4->CR1 |= (0x1 << 7);
	//2.设置边沿对齐模式
	TIM4->CR1 &= (~(0x3 << 5));
	//3.设置递减计数器
	TIM4->CR1 |= (0x1 << 4);
	//4.设置计数器使能
	TIM4->CR1 |= (0x1 << 0);

}
//TIM16--->PF6
//马达RCC章节初始化
void md_rcc_init()
{
	//TIM16使能
	RCC->MP_APB2ENSETR |= (0x1 << 3);
	//GPIOF使能
	RCC->MP_AHB4ENSETR |= (0x1 << 5);
}
//马达GPIO章节初始化
void md_gpio_init()
{
	//设置PF6引脚为复用模式
	GPIOF->MODER &= (~(0x3 <<12));
	GPIOF->MODER |= (0x1 << 13);
	//设置PF6引脚功能为AF1--->TIM16_CH1
	GPIOF->AFRL &= (~(0xf << 24));
	GPIOF->AFRL |= (0x1 << 24);
}
//马达TIM16章节初始化
void md_tim16_init()
{
	//配置TIM16_PSC寄存器
	TIM16->PSC &= (~(0xffff << 0));
	TIM16->PSC |= (0xD0 << 0);

	//配置TIM16_ARR寄存器——影响周期和频率
	TIM16->ARR &= (~(0xffff << 0));
	TIM16->ARR |= (0x3E8 << 0);

	//配置TIM16_CCR1寄存器
	TIM16->CCR1 &= (~(0xffff << 0));
	TIM16->CCR1 |= (0x12C << 0);

	//配置TIM16_BDTR寄存器
	TIM16->BDTR |= (0x1 << 15);
	
	//配置TIM16_CCMR1寄存器
	//1.设置为pwm1模式
	TIM16->CCMR1 &= (~(0x1 << 16));
	TIM16->CCMR1 &= (~(0x1 << 4));
	TIM16->CCMR1 |= (0x3 << 5);
	//2.设置预加载使能
	TIM16->CCMR1 |= (0x1 << 3);
	//3.设置为输出模式
	TIM16->CCMR1 &= (~(0x3 << 0));

	//配置TIM16_CCER寄存器
	//1.配置起始状态高电平
	TIM16->CCER &= (~(0x1 << 1));
	//2.配置输出使能
	TIM16->CCER |= (0x1 << 0);

	//配置tim计算器方式--TIM16_CR1
	//1.自动重载计数器预加载使能
	TIM16->CR1 |= (0x1 << 7);
	//2.设置边沿对齐模式
	TIM16->CR1 &= (~(0x3 << 5));
	//3.设置递减计数器
	TIM16->CR1 |= (0x1 << 4);
	//4.设置计数器使能
	TIM16->CR1 |= (0x1 << 0);

}

//TIM1--->PE9
//风扇RCC章节初始化
void fs_rcc_init()
{
	//TIM1使能
	RCC->MP_APB2ENSETR |= (0x1 << 0);
	//GPIOE使能
	RCC->MP_AHB4ENSETR |= (0x1 << 4);
}
//风扇GPIO章节初始化
void fs_gpio_init()
{
	//设置PE9引脚为复用模式
	GPIOE->MODER &= (~(0x3 <<18));
	GPIOE->MODER |= (0x1 << 19);
	//设置PE9引脚功能为AF1--->TIM1_CH1
	GPIOE->AFRH &= (~(0xf << 4));
	GPIOE->AFRH |= (0x1 << 4);
}
//风扇TIM1章节初始化
void fs_tim1_init()
{
	//配置TIM1_PSC寄存器
	TIM1->PSC &= (~(0xffff << 0));
	TIM1->PSC |= (0xD0 << 0);

	//配置TIM1_ARR寄存器——影响周期和频率
	TIM1->ARR &= (~(0xffff << 0));
	TIM1->ARR |= (0x3E8 << 0);

	//配置TIM1_CCR1寄存器
	TIM1->CCR1 &= (~(0xffff << 0));
	TIM1->CCR1 |= (0x12C << 0);

	//配置TIM1_BDTR寄存器
	TIM1->BDTR |= (0x1 << 15);

	//配置TIM1_CCMR1寄存器
	//1.设置为pwm1模式
	TIM1->CCMR1 &= (~(0x1 << 16));
	TIM1->CCMR1 &= (~(0x1 << 4));
	TIM1->CCMR1 |= (0x3 << 5);
	//2.设置预加载使能
	TIM1->CCMR1 |= (0x1 << 3);
	//3.设置为输出模式
	TIM1->CCMR1 &= (~(0x3 << 0));

	//配置TIM1_CCER寄存器
	//1.配置起始状态高电平
	TIM1->CCER &= (~(0x1 << 1));
	//2.配置输出使能
	TIM1->CCER |= (0x1 << 0);

	//配置tim计算器方式--TIM1_CR1
	//1.自动重载计数器预加载使能
	TIM1->CR1 |= (0x1 << 7);
	//2.设置边沿对齐模式
	TIM1->CR1 &= (~(0x3 << 5));
	//3.设置递减计数器
	TIM1->CR1 |= (0x1 << 4);
	//4.设置计数器使能
	TIM1->CR1 |= (0x1 << 0);
}

三、main.c——函数的调用

#include "pwm.h"
extern void printf(const char *fmt, ...);
void delay_ms(int ms)
{
	int i,j;
	for(i = 0; i < ms;i++)
		for (j = 0; j < 1800; j++);
}


int main()
{
	//蜂鸣器的初始化
	fm_rcc_init();
	fm_gpio_init();
	fm_tim4_init();
	//马达的初始化
	md_rcc_init();
	md_gpio_init();
	md_tim16_init();
	//风扇的初始化
	fs_rcc_init();
	fs_gpio_init();
	fs_tim1_init();
	while(1)
	{
	}
	return 0;
}