红外寻迹传感器具有一对红外线发射管与接收管,发射管发射出一定频率的红外线,当检测方向遇到障碍物(反射面)时,红外线反射回来被接收管接收,经过比较器电路处理之后,输出接口会输出一个数字信号(低电平或高电平,取决于电路设计),有效范围一般为2~30CM。传感器主动红外反射探测,因此反射率和形状是探测距离的关键。其中黑色探测距离小,白色距离大;小面积物体距离小,大面积距离大。

本实例将演示如何使用红外寻迹传感器。本次使用到的传感器,在检测到检测方向障碍物信号时,电路持续输出低电平。
开发环境搭建、系统时钟配置、调试配置及串口配置,请参考:
传感器配置如下:

保存配置并生成代码。
1)基本定义
/*
* infrared_tracking_sensor.h
*
* Created on: Apr 23, 2022
* Author: jenson
*/
#ifndef __INFRARED_TRACKING_SENSOR_H__
#define __INFRARED_TRACKING_SENSOR_H__
#include <stdio.h>
#include <stm32f1xx_hal.h>
#include "main.h"
typedef struct {
uint16_t id;
GPIO_TypeDef *GPIOx; // 总线端口
uint16_t GPIO_Pin; // 总线引脚
} infrared_tracking_sensor_t;
/**
*@brief 红外寻迹传感器状态
*@param sensor 开关对象
*@return 当开关闭合时,返回1;否则,返回0
*/
uint8_t infrared_tracking_sensor_check(infrared_tracking_sensor_t* sensor);
#endif /* __INFRARED_TRACKING_SENSOR_H__ */
2)传感器状态检测
/*
* infrared_tracking_sensor.c
*
* Created on: Apr 23, 2022
* Author: jenson
*/
#include "infrared_tracking_sensor.h"
uint8_t infrared_tracking_sensor_check(infrared_tracking_sensor_t *sensor) {
// 读取传感器输出电平
if (HAL_GPIO_ReadPin(sensor->GPIOx, sensor->GPIO_Pin) == GPIO_PIN_SET) {
return 1;
}
return 0;
}
3)主程序
在main.c文件中添加如下代码:
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <stdio.h>
#include "infrared_tracking_sensor/infrared_tracking_sensor.h"
/* USER CODE END Includes */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
infrared_tracking_sensor_t sensor;
/* USER CODE END PV */
int main(void) {
/* USER CODE BEGIN 1 */
/* 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_USART1_UART_Init();
/* USER CODE BEGIN 2 */
sensor.id = 1;
sensor.GPIO_Pin = INFRARED_TRACKING_SENSOR_Pin;
sensor.GPIOx = INFRARED_TRACKING_SENSOR_GPIO_Port;
printf("****STM32CubeIDE:Infrared Tracking Sensor****\r\n");
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1) {
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
if (infrared_tracking_sensor_check(&sensor)) {
printf("sensor tracked black line\r\n");
} else {
printf("sensor tracked while line\r\n");
}
HAL_Delay(10);
}
/* USER CODE END 3 */
}
程序运行结果:

前面的驱动代码是基于循环轮询实现,比较耗CPU。可以通过外部中断方式来对传感器输出信号进行检测。关于外部中断使用,请参考:
传感器的中断方式驱动配置如下:


保存配置并生成代码。
1)基本定义
/*
* infrared_tracking_sensor.h
*
* Created on: Apr 23, 2022
* Author: jenson
*/
#ifndef __INFRARED_TRACKING_SENSOR_H__
#define __INFRARED_TRACKING_SENSOR_H__
#include <stdio.h>
#include <stm32f1xx_hal.h>
#include "main.h"
/***
* @brief 红外寻迹感器中断回调函数
* @param sensor_id 传感器编码
*/
typedef void (*infrared_tracking_sensor_callback)(uint16_t sensor_id);
typedef struct {
uint16_t id;
GPIO_TypeDef *GPIOx; // 总线端口
uint16_t GPIO_Pin; // 总线引脚
infrared_tracking_sensor_callback callback; // 中断服务回调
} infrared_tracking_sensor_t;
#endif /* __INFRARED_TRACKING_SENSOR_H__ */
2)中断服务实现
在stm32f1xx_it.c文件中添加如下代码:
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "infrared_tracking_sensor/infrared_tracking_sensor.h"
/* USER CODE END Includes */
/* USER CODE BEGIN EV */
extern infrared_tracking_sensor_t sensor;
/* USER CODE END EV */
/* USER CODE BEGIN 1 */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin) {
if(GPIO_Pin == sensor.GPIO_Pin){
if(sensor.callback){
sensor.callback(sensor.id);
}
}
}
/* USER CODE END 1 */
3)主程序
在main.c文件中添加如下代码:
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <stdio.h>
#include "infrared_tracking_sensor/infrared_tracking_sensor.h"
/* USER CODE END Includes */
/* USER CODE BEGIN PV */
infrared_tracking_sensor_t sensor;
/* USER CODE END PV */
/* USER CODE BEGIN PFP */
void on_infrared_tracking_sensor_callback(uint16_t sensor_id);
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
void on_infrared_tracking_sensor_callback(uint16_t sensor_id){
printf("sensor %d detected black line\r\n",sensor_id);
}
/* USER CODE END 0 */
int main(void) {
/* USER CODE BEGIN 1 */
/* 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_USART1_UART_Init();
/* USER CODE BEGIN 2 */
sensor.id = 1;
sensor.GPIO_Pin = INFRARED_TRACKING_SENSOR_Pin;
sensor.GPIOx = INFRARED_TRACKING_SENSOR_GPIO_Port;
sensor.callback = on_infrared_tracking_sensor_callback;
printf("****STM32CubeIDE:Infrared Tracking Sensor****\r\n");
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1) {
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
程序运行结果:
