仅仅关闭重映射之后，IO口就失效了

BillowsCT · 发表于 2019-12-1 12:13:32

如题
安装正点原子精英板 PWM输出实验修改的，原函数中，是使用重映射把TM3 CH2默认的PA7口重映射到PB5，
我仅仅把TIM3 CH2的重映射口关闭，其他地方没动，PWM就测不到波形了

//配置函数
#include "servo.h"

void GPIOA_Init(){

GPIO_InitTypeDef GPIO_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE);
//GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3,ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOB, &GPIO_InitStructure);
}

void TIM3_Init(){

TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

TIM_TimeBaseStructure.TIM_Period=199;
TIM_TimeBaseStructure.TIM_Prescaler=7199;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

TIM_Cmd(TIM3, ENABLE);
}

void PWM_Init(){

TIM_OCInitTypeDef  TIM_OCInitStructure;

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;

TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM3,TIM_OCPreload_Enable);

TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OC2Init(TIM3, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM3,TIM_OCPreload_Enable);

TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OC2Init(TIM3, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM3,TIM_OCPreload_Enable);

TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OC2Init(TIM3, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM3,TIM_OCPreload_Enable);

TIM_CtrlPWMOutputs(TIM3,ENABLE);
}

void SERVO_Init(void){

TIM3_Init();
PWM_Init();
GPIOA_Init();
}

//主函数

int main(void)
{

SERVO_Init();    //不分频。PWM频率=72000000/900=80Khz
   while(1)
{
TIM_SetCompare2(TIM3,100);
}
}

如果现在把PA7口改成重映射PB5是有波形的