【stm32简单外设篇】- 手指心跳检测模块
一、适用场景
适用场景：心率/脉搏检测实验、可穿戴设备入门（手环/指夹）、健康监测教学演示、生理信号采集与滤波算法练习、运动/康复监测、物联网健康数据采集等。
二、器材清单
手指心跳检测模块×1
stm32f103（或其它 STM32）开发板 ×1
若干杜邦线 ×1组
稳定电源 5V×1
三、工作原理（要点）
当手指放在发射器与接收器之间，红外发射LED发射的光将穿过手指，到被接收器接收。而血压会随着脉搏变化，导致红外接收器接收到的光通量也会随之变化，因此可以通过红外光接收的情况来统计监测心跳，但是这也导致它很容易受干扰，如环境光照强度，倾斜角度等。
四、接线示意
GND→GND
VCC→5V/3.3V电源
标准库
S→PC1
HAL库
S→PA0
五、示例代码
标准库
#include "adc_time.h" #include "stm32f10x.h" volatile uint16_t adc_light; void adcgpio_init() { GPIO_InitTypeDef PC; //使能时钟 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC,ENABLE); PC.GPIO_Pin = GPIO_Pin_1; PC.GPIO_Mode = GPIO_Mode_AIN; GPIO_Init(GPIOC,&PC); } void adcmode_init() { ADC_InitTypeDef adc; NVIC_InitTypeDef nvic; RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC2,ENABLE); adc.ADC_Mode=ADC_Mode_Independent; adc.ADC_ScanConvMode = DISABLE; adc.ADC_ContinuousConvMode = ENABLE; adc.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None; adc.ADC_DataAlign = ADC_DataAlign_Right; adc.ADC_NbrOfChannel = 1; ADC_Init(ADC2,&adc); RCC_ADCCLKConfig(RCC_PCLK2_Div8); ADC_RegularChannelConfig(ADC2,ADC_Channel_11,1,ADC_SampleTime_55Cycles5); ADC_ITConfig(ADC2,ADC_IT_EOC,ENABLE); ADC_Cmd(ADC2,ENABLE); ADC_ResetCalibration(ADC2); while(ADC_GetResetCalibrationStatus(ADC2)); ADC_StartCalibration(ADC2); while(ADC_GetCalibrationStatus(ADC2)); ADC_SoftwareStartConvCmd(ADC2,ENABLE); NVIC_PriorityGroupConfig(NVIC_PriorityGroup_3); nvic.NVIC_IRQChannel = ADC1_2_IRQn; nvic.NVIC_IRQChannelPreemptionPriority = 3; nvic.NVIC_IRQChannelSubPriority = 0; nvic.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&nvic); } void adctime_Init() { adcgpio_init(); adcmode_init(); } void ADC1_2_IRQHandler(void) { if(ADC_GetITStatus(ADC2,ADC_IT_EOC) == SET) { adc_light = ADC_GetConversionValue(ADC2); } ADC_ClearITPendingBit(ADC2,ADC_IT_EOC); } #include "stm32f10x.h" #include "stdio.h" #include "bsp_SysTick.h" #include "adc_time.h" #include "breathing.h" #include "bsp_usart.h" char showlight[20]; extern volatile uint16_t adc_light; int main() { static double oldValue = 0; double value =0; SysTick_Init(); USART_Config(); adctime_Init(); while(1) { value = 0.75 * oldValue + (1 - 0.75) * adc_light;//这个平滑就是取本次和上一次测量数据的加权平均值 sprintf(showlight,"light:%f\n",value); Usart_SendString(USART1,showlight); oldValue = value; Delay_us(1000000); } // return 0; }HAL库
int main(void) { /* USER CODE BEGIN 1 */ char show[20]={0}; static double oldValue = 0; double value =0; /* USER CODE END 1 */ /* MCU Configuration--------------------------------------------------------*/ /* Reset of all peripherals, Initializes the Flash interface and the Systick. */ HAL_Init(); /* USER CODE BEGIN Init */ /* USER CODE END Init */ /* Configure the system clock */ SystemClock_Config(); /* USER CODE BEGIN SysInit */ /* USER CODE END SysInit */ /* Initialize all configured peripherals */ MX_GPIO_Init(); MX_ADC1_Init(); MX_USART1_UART_Init(); /* USER CODE BEGIN 2 */ /* USER CODE END 2 */ /* Infinite loop */ /* USER CODE BEGIN WHILE */ while (1) { //#1。启动常规序列 HAL_ADC_Start(&hadc1); //#2.等待转换完成 HAL_ADC_PollForConversion(&hadc1,HAL_MAX_DELAY); //#3。获取结果 uint32_t dr = HAL_ADC_GetValue(&hadc1); //#4.把结果转换成电压 value = 0.75 * oldValue + (1 - 0.75) * dr;//这个平滑就是取本次和上一次测量数据的加权平均值 sprintf(show,"adc:%d,light:%f\r\n",dr,value); HAL_UART_Transmit(&huart1,show,strlen(show),HAL_MAX_DELAY); oldValue = value; HAL_Delay(500); // if（voltage>1.5f）//光线暗 // HAL_GPIO_WritePin(GPIOA,GPIO_PIN_13,GPIO_PIN_SET);// 灭灯 // else//光线亮 // HAL_GPIO_WritePin（GPIOA,GPIO_PIN_13，GPIO_PIN_RESET); // 亮灯 /* USER CODE END WHILE */ /* USER CODE BEGIN 3 */ } /* USER CODE END 3 */ } 六、讲解视频
https://www.bilibili.com/video/BV1VCvvBCEeb/?spm_id_from=333.1387.search.video_card.click&vd_source=f7dfe1b14f260b9cc3a146d2dbfd0719
https://www.bilibili.com/video/BV19xvBBQER4/?spm_id_from=333.1387.search.video_card.click&vd_source=f7dfe1b14f260b9cc3a146d2dbfd0719
https://www.bilibili.com/video/BV1QhvBBEE6G/?spm_id_from=333.1387.search.video_card.click&vd_source=f7dfe1b14f260b9cc3a146d2dbfd0719