HC-SR501传感器接入STM32F10x后始终显示0，求排查问题

API 探路者

2026-7-4

HC-SR501运动传感器始终输出0的排查方案

硬件排查步骤

电源验证：HC-SR501需5V供电，用万用表确认开发板5V引脚输出正常，传感器GND与开发板GND可靠连接，无虚焊或接触不良。
输出引脚检测：直接测量传感器OUT引脚电平，触发运动时观察是否能跳转为高电平（3.3V/5V均可，STM32F10x兼容5V输入）。同时确认OUT引脚确实连接到代码中读取的GPIOA_Pin_0。
传感器参数调节：旋转传感器上的灵敏度电位器，适当调高检测灵敏度；传感器通电后需约1分钟初始化时间，等待完成后再测试运动检测。
硬件替换：更换同型号HC-SR501传感器，排除传感器本身损坏的可能。

代码逻辑排查

GPIO配置合理性：代码中将GPIOA_Pin_0配置为GPIO_Mode_IN_FLOATING（浮空输入），若传感器输出低电平，浮空输入可能受环境干扰。建议改为GPIO_Mode_IPU（上拉输入）或GPIO_Mode_IPD（下拉输入）测试，匹配传感器输出特性。
读取逻辑验证：主循环中通过GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_0)轮询电平，但代码中无延时，LCD刷新过快可能掩盖瞬间变化。可添加短延时（比如delay(100000)），或改为串口打印电平值，排除LCD显示的干扰。
冗余代码清理：代码中保留了EXTI中断相关配置和EXTI9_5_IRQHandler函数，但EXTI_Configure()被注释，这部分代码完全未生效，建议删除或启用（若想用中断检测运动）。若启用中断，需注意：
- 取消//EXTI_Configure();注释
- 确认传感器OUT引脚连接到GPIOE_Pin_8（代码中EXTI配置的引脚），而非GPIOA_Pin_0
- 调整EXTI触发方式为EXTI_Trigger_Rising（传感器检测到运动时输出高电平，上升沿触发）
引脚冲突检查：确认GPIOA_Pin_0未被其他外设初始化占用，代码中ADC使用的是PC2（ADC通道12），无冲突，但需核对开发板原理图。

测试用极简代码

若怀疑LCD显示问题，可先使用以下极简代码验证STM32是否能正确读取传感器电平：

#include "stm32f10x.h"
#include "stm32f10x_gpio.h"
#include "stm32f10x_rcc.h"

void RCC_Configure(void) {
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
}

void GPIO_Configure(void) {
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
}

void USART1_Init(void) {
    // 初始化USART1用于打印，根据自己的开发板配置
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 | RCC_APB2Periph_GPIOA, ENABLE);
    GPIO_InitTypeDef GPIO_InitStructure;
    // TX引脚配置
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    // USART配置
    USART_InitTypeDef USART_InitStructure;
    USART_InitStructure.USART_BaudRate = 9600;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Tx;
    USART_Init(USART1, &USART_InitStructure);
    USART_Cmd(USART1, ENABLE);
}

void USART_SendChar(USART_TypeDef* USARTx, char ch) {
    while(USART_GetFlagStatus(USARTx, USART_FLAG_TXE) == RESET);
    USART_SendData(USARTx, (uint16_t)ch);
}

void USART_SendString(USART_TypeDef* USARTx, char* str) {
    while(*str) {
        USART_SendChar(USARTx, *str++);
    }
}

void delay(uint32_t t) {
    for(uint32_t i=0; i<t; i++);
}

int main(void) {
    SystemInit();
    RCC_Configure();
    GPIO_Configure();
    USART1_Init();
    
    while(1) {
        uint32_t inputData = GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_0);
        if(inputData) {
            USART_SendString(USART1, "Motion detected!\r\n");
        } else {
            USART_SendString(USART1, "No motion!\r\n");
        }
        delay(1000000);
    }
}

用户原始代码

#include <stdbool.h>
#include "stm32f10x.h"
#include "stm32f10x_exti.h"
#include "stm32f10x_gpio.h"
#include "stm32f10x_usart.h"
#include "stm32f10x_rcc.h"
#include "core_cm3.h"
#include "stm32f10x_adc.h"
#include "lcd.h"
#include "touch.h"
#include "misc.h"

/* function prototype */
void RCC_Configure(void);
void GPIO_Configure(void);
void USART1_Init(void);
void USART2_Init(void);
void NVIC_Configure(void);

void EXTI9_5_IRQHandler(void);

uint16_t value, x, y;
bool motionDetected = false;
int color[12] = {WHITE, CYAN, BLUE, RED, MAGENTA, LGRAY, GREEN, YELLOW, BROWN, BRRED, GRAY};
//---------------------------------------------------------------------------------------------------
void RCC_Configure(void)
{
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC,ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1,ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
}


void GPIO_Configure(void)
{
GPIO_InitTypeDef GPIO_InitStructure;

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOC, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
}


void ADC_Configure(void) {
        ADC_InitTypeDef ADC_12;
        ADC_12.ADC_ContinuousConvMode = ENABLE;
        ADC_12.ADC_DataAlign = ADC_DataAlign_Right;
        ADC_12.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
ADC_12.ADC_Mode = ADC_Mode_Independent;
ADC_12.ADC_NbrOfChannel = 1;
ADC_12.ADC_ScanConvMode = DISABLE;

ADC_Init(ADC1, &ADC_12);
ADC_RegularChannelConfig(ADC1, ADC_Channel_12, 1, ADC_SampleTime_239Cycles5);
ADC_ITConfig(ADC1,ADC_IT_EOC, ENABLE);
ADC_Cmd(ADC1, ENABLE);
ADC_ResetCalibration(ADC1);
while(ADC_GetResetCalibrationStatus(ADC1));
ADC_StartCalibration(ADC1);
while(ADC_GetCalibrationStatus(ADC1));
ADC_SoftwareStartConvCmd(ADC1, ENABLE);
}


void EXTI_Configure(void)
{
    EXTI_InitTypeDef EXTI_InitStructure;

    GPIO_EXTILineConfig(GPIO_PortSourceGPIOE, GPIO_PinSource8);
    EXTI_InitStructure.EXTI_Line = EXTI_Line8;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);
}


void NVIC_Configure(void) {

    NVIC_InitTypeDef NVIC_InitStructure;

    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1); // need modify

    NVIC_InitStructure.NVIC_IRQChannel = ADC1_2_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x0; // TODO
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x0; // TODO
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

}

void ADC1_2_IRQHandler() {
if(ADC_GetITStatus(ADC1,ADC_IT_EOC) != RESET) {
value = ADC_GetConversionValue(ADC1);
        }
ADC_ClearITPendingBit(ADC1, ADC_IT_EOC);
}


void delay(uint32_t t) {
  for (int i = 0; i < t; i++) {}
}


void EXTI9_5_IRQHandler(void) {
    if (EXTI_GetITStatus(EXTI_Line8) != RESET) {
        if (GPIO_ReadInputDataBit(GPIOE, GPIO_Pin_8) != Bit_RESET) {
          if (!motionDetected)  { motionDetected = true; }
        }
        EXTI_ClearITPendingBit(EXTI_Line8);
    }
}



int main(void)
{

    SystemInit();

    RCC_Configure();

    GPIO_Configure();

    ADC_Configure();

    //EXTI_Configure();

    NVIC_Configure();

    LCD_Init();
    Touch_Configuration();
    Touch_Adjust();
    LCD_Clear(WHITE);

    while (1) {
/*
if 사운드 < threshold:
  블루투스로 전송
IF MOSITION == 1:
  블루투스로 전송

*/
        uint32_t inputData = GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_0);
        LCD_ShowNum(0, 0, (uint32_t) inputData, 10, BLACK, WHITE);
        LCD_ShowNum(80,120,value,4,BLACK,WHITE);
        if (motionDetected) {
              motionDetected = false;
              LCD_ShowString(80, 150, "motion detected", BLACK, WHITE);
        }
        else {
              LCD_ShowString(80, 150, "motion not detected", BLACK, WHITE);
        }
        
        //delay(1000000);
    }
   return 0;
}

内容的提问来源于stack exchange，提问作者Daulet Suyenish

HC-SR501传感器接入STM32F10x后始终显示0，求排查问题

硬件排查步骤 #

代码逻辑排查 #

测试用极简代码 #

用户原始代码 #

硬件排查步骤

代码逻辑排查

测试用极简代码

用户原始代码