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【物联网】HC-SR04超声波测距模块

目录

基本介绍

 测距工作原理

 实现的程序

主函数模块：

Delay延时模块：

OLED模块：

HC-SR04超声波模块：

时间函数模块：

蜂鸣器模块：

基本介绍

HC-SR04超声波测距模块是一种常用的测距传感器。该模块通过发射一定频率的超声波脉冲，然后接收反射回来的超声波脉冲，从而测量出目标物体与模块之间的距离。

其测距原理基于声速在空气中传播的速度以及声波的发射和反射时间计算得出。首先，MCU向超声波测距模块发送一个高电平脉冲来触发发射器，发射器就会发射超声波。当超声波遇到障碍物后，会发生反射。接受器就会收到这些反射波，然后把信号传回到MCU，并计算出来传播时间。通过时间和声速的乘积，就可以得到目标物体与超声波测距模块之间的距离。

HC-SR04超声波测距模块一般需要至少四个引脚进行连接。其中，VCC和GND引脚分别连接到电源正负极，而Trig和Echo引脚则需要连接到控制器的数字输入输出引脚上。

具体来说，Trig引脚接收到高电平的触发信号后，触发超声波发射器开始发射超声波，在发射后10微秒内，Echo引脚会返回一个高电平信号，表示已经收到了反射波。然后，控制器就会记录下Echo引脚的高电平持续时间就可以计算出距离。

  本模块有一个接口：4 Pin 供电及通信接口。为 2.54mm 间距的弯排针，如图 4所示：
从左到右依次编号1,2,3,4。它们的定义如下：
1号 Pin ：接 VCC 电源（直流 3V-5.5V）。
2号 Pin ：接外部电路的 Trig 端，向此管脚输入一个 10uS以上的高电平，可触发模块测距。
3号 Pin ：接外部电路的 Echo端，当测距结束时，此管脚会输出一个高电平，电平宽度为超声波往返时间之和。
4号 Pin：接外部电路的地。 

需要注意的是，需要在代码中加入一定的延时来等待信号的传输和回传，从而准确计算出距离。同时，在进行超声波测距时，应避免在靠近模块的距离内进行测试，以免信号干扰引起精度变化，并且需要在测试时按照实际情况进行多次测量并取平均值，以提高测量的准确度。

 测距工作原理

模块测距的时序如图 5 所示：
图 5 表明：只需要在 Trig 管脚输入一个10US以上的高电平，系统便可发出8个40KHZ的超声波脉冲，然后检测回波信号。当检测到回波信号后，通过 Echo 管脚输出。
根据 Echo 管脚输出高电平的持续时间可以计算距离值。即距离值为：(高电平时间*340m/s)/2。
当测量距离超过 HC-SR04 的测量范围时，仍会通过 Echo 管脚输出高电平的信号，高电平的宽度约为 66ms。如图 6 所示：
测量周期：当接收到 HC-SR04 通过 Echo 管脚输出的高电平脉冲后，便可进行下一次测量，所以测量周期取决于测量距离，当距离被测物体很近时，Echo 返回的脉冲宽度较窄，测量周期就短；当距离被测物体比较远时，Echo 返回的脉冲宽度较宽，测量周期也就相应的变长。
最坏情况下，被测物体超出超声波模块的测量范围，此时返回的脉冲宽度最长，约为 66ms，所以最坏情况下的测量周期稍大于 66ms 即可（取 70ms 足够）。

 实现的程序

实现的功能是使用stm32f103实现超声波传感器前方10cm内有障碍物时，蜂鸣器会响，并且随着距离变小，蜂鸣器声音频率会变快，同时在0.96寸oled显示屏上显示距离参数。

主函数模块：

#include "stm32f10x.h"                  // Device header
#include "Delay.h"
#include "OLED.h"
#include "Timer.h"
#include "HCSR04.h"
#include "Buzzer.H"

uint64_t numlen(uint64_t num)//计算数字的长度
{
    uint64_t len = 1;        // 初始长度为1
    for(; num > 9; ++len)    // 判断num是否大于9，否则长度+1
        num /= 10;	         // 使用除法进行运算，直到num小于1
    return len;              // 返回长度的值
}

int main(void)
{	
	OLED_Init();		//初始化OLED屏
	Timer_Init();		//初始化定时器
	HC_SR04_Init();		//初始化超声波测距模块
	Buzzer_Init();
	
	
	
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);  // 打开 GPIOA 时钟

    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;  // PA0 引脚
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;  // 推挽输出模式
    GPIO_Init(GPIOA, &GPIO_InitStructure);
	GPIO_ResetBits (GPIOA,GPIO_Pin_3);
	OLED_ShowString(1, 1, "Distance:");		//OLED屏输出字符串
	
	while (1)
	{
		int Distance_mm=sonar_mm();			//获取距离测量结果，单位毫米（mm）		
		int Distance_m=Distance_mm/1000;	//转换为米（m）为单位，将整数部分放入Distance_m
		int Distance_m_p=Distance_mm%1000;	//转换为米（m）为单位，将小数部分放入Distance_m_p
		
		OLED_ShowString(2,1,"               ");			//将OLDE屏第2行清屏
		OLED_ShowNum(2, 1,Distance_m,numlen(Distance_m));	//显示测量结果的整数部分
		OLED_ShowChar(2, 1+numlen(Distance_m), '.');		//显示小数点
		
		if(Distance_m_p<100){								//判断是否小于100毫米
			OLED_ShowChar(2, 1+numlen(Distance_m)+1,'0');								//因为单位是米，所以小于10cm时要加0
			OLED_ShowNum(2, 1+numlen(Distance_m)+2,Distance_m_p,numlen(Distance_m_p));	//显示测量结果的小数部分
			OLED_ShowChar(2, 1+numlen(Distance_m)+2+numlen(Distance_m_p), 'm');			//显示单位
		}
		else																			// https://blog.zeruns.tech
		{
			OLED_ShowNum(2, 1+numlen(Distance_m)+1,Distance_m_p,numlen(Distance_m_p));	//显示测量结果的小数部分
			OLED_ShowChar(2, 1+numlen(Distance_m)+1+numlen(Distance_m_p), 'm');			//显示单位
		}
		OLED_ShowString(3,1,"               ");			//将OLDE屏第3行清屏
		OLED_ShowNum(3, 1,Distance_mm,numlen(Distance_mm));		//显示单位为毫米的距离结果
		OLED_ShowString(3, 1 + numlen(Distance_mm), "mm");
		
		if(Distance_mm<=100&Distance_mm>=75)
		{
			Buzzer_ON();
			Delay_ms(100);
			Buzzer_OFF();
			Delay_ms(100);
		}
		if(Distance_mm<=74&Distance_mm>=50)
		{
			Buzzer_ON();
			Delay_ms(75);
			Buzzer_OFF();
			Delay_ms(75);
		}
		if(Distance_mm<=49)
		{
			Buzzer_ON();
			Delay_ms(50);
			Buzzer_OFF();
			Delay_ms(50);
		}
	}
}

Delay延时模块：

//delay函数的源文件
#include "stm32f10x.h"

/**
  * @brief  微秒级延时
  * @param  xus 延时时长，范围：0~233015
  * @retval 无
  */
void Delay_us(uint32_t xus)
{
	SysTick->LOAD = 72 * xus;				//设置定时器重装值
	SysTick->VAL = 0x00;					//清空当前计数值
	SysTick->CTRL = 0x00000005;				//设置时钟源为HCLK，启动定时器
	while(!(SysTick->CTRL & 0x00010000));	//等待计数到0
	SysTick->CTRL = 0x00000004;				//关闭定时器
}

/**
  * @brief  毫秒级延时
  * @param  xms 延时时长，范围：0~4294967295
  * @retval 无
  */
void Delay_ms(uint32_t xms)
{
	while(xms--)
	{
		Delay_us(1000);
	}
}
 
/**
  * @brief  秒级延时
  * @param  xs 延时时长，范围：0~4294967295
  * @retval 无
  */
void Delay_s(uint32_t xs)
{
	while(xs--)
	{
		Delay_ms(1000);
	}
} 

//delay模块的头文件
#ifndef __DELAY_H
#define __DELAY_H

void Delay_us(uint32_t us);
void Delay_ms(uint32_t ms);
void Delay_s(uint32_t s);

#endif

OLED模块：

//oled模块的源文件
#include "stm32f10x.h"
#include "OLED_Font.h"

/*引脚配置*/
#define OLED_W_SCL(x)		GPIO_WriteBit(GPIOB, GPIO_Pin_6, (BitAction)(x))
#define OLED_W_SDA(x)		GPIO_WriteBit(GPIOB, GPIO_Pin_7, (BitAction)(x))

/*引脚初始化*/
void OLED_I2C_Init(void)
{
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
	
	GPIO_InitTypeDef GPIO_InitStructure;
 	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
 	GPIO_Init(GPIOB, &GPIO_InitStructure);
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
 	GPIO_Init(GPIOB, &GPIO_InitStructure);
	
	OLED_W_SCL(1);
	OLED_W_SDA(1);
}

/**
  * @brief  I2C开始
  * @param  无
  * @retval 无
  */
void OLED_I2C_Start(void)
{
	OLED_W_SDA(1);
	OLED_W_SCL(1);
	OLED_W_SDA(0);
	OLED_W_SCL(0);
}

/**
  * @brief  I2C停止
  * @param  无
  * @retval 无
  */
void OLED_I2C_Stop(void)
{
	OLED_W_SDA(0);
	OLED_W_SCL(1);
	OLED_W_SDA(1);
}

/**
  * @brief  I2C发送一个字节
  * @param  Byte 要发送的一个字节
  * @retval 无
  */
void OLED_I2C_SendByte(uint8_t Byte)
{
	uint8_t i;
	for (i = 0; i < 8; i++)
	{
		OLED_W_SDA(Byte & (0x80 >> i));
		OLED_W_SCL(1);
		OLED_W_SCL(0);
	}
	OLED_W_SCL(1);	//额外的一个时钟，不处理应答信号
	OLED_W_SCL(0);
}

/**
  * @brief  OLED写命令
  * @param  Command 要写入的命令
  * @retval 无
  */
void OLED_WriteCommand(uint8_t Command)
{
	OLED_I2C_Start();
	OLED_I2C_SendByte(0x78);		//从机地址
	OLED_I2C_SendByte(0x00);		//写命令
	OLED_I2C_SendByte(Command); 
	OLED_I2C_Stop();
}

/**
  * @brief  OLED写数据
  * @param  Data 要写入的数据
  * @retval 无
  */
void OLED_WriteData(uint8_t Data)
{
	OLED_I2C_Start();
	OLED_I2C_SendByte(0x78);		//从机地址
	OLED_I2C_SendByte(0x40);		//写数据
	OLED_I2C_SendByte(Data);
	OLED_I2C_Stop();
}

/**
  * @brief  OLED设置光标位置
  * @param  Y 以左上角为原点，向下方向的坐标，范围：0~7
  * @param  X 以左上角为原点，向右方向的坐标，范围：0~127
  * @retval 无
  */
void OLED_SetCursor(uint8_t Y, uint8_t X)
{
	OLED_WriteCommand(0xB0 | Y);					//设置Y位置
	OLED_WriteCommand(0x10 | ((X & 0xF0) >> 4));	//设置X位置高4位
	OLED_WriteCommand(0x00 | (X & 0x0F));			//设置X位置低4位
}

/**
  * @brief  OLED清屏
  * @param  无
  * @retval 无
  */
void OLED_Clear(void)
{  
	uint8_t i, j;
	for (j = 0; j < 8; j++)
	{
		OLED_SetCursor(j, 0);
		for(i = 0; i < 128; i++)
		{
			OLED_WriteData(0x00);
		}
	}
}

/**
  * @brief  OLED显示一个字符
  * @param  Line 行位置，范围：1~4
  * @param  Column 列位置，范围：1~16
  * @param  Char 要显示的一个字符，范围：ASCII可见字符
  * @retval 无
  */
void OLED_ShowChar(uint8_t Line, uint8_t Column, char Char)
{      	
	uint8_t i;
	OLED_SetCursor((Line - 1) * 2, (Column - 1) * 8);		//设置光标位置在上半部分
	for (i = 0; i < 8; i++)
	{
		OLED_WriteData(OLED_F8x16[Char - ' '][i]);			//显示上半部分内容
	}
	OLED_SetCursor((Line - 1) * 2 + 1, (Column - 1) * 8);	//设置光标位置在下半部分
	for (i = 0; i < 8; i++)
	{
		OLED_WriteData(OLED_F8x16[Char - ' '][i + 8]);		//显示下半部分内容
	}
}

/**
  * @brief  OLED显示字符串
  * @param  Line 起始行位置，范围：1~4
  * @param  Column 起始列位置，范围：1~16
  * @param  String 要显示的字符串，范围：ASCII可见字符
  * @retval 无
  */
void OLED_ShowString(uint8_t Line, uint8_t Column, char *String)
{
	uint8_t i;
	for (i = 0; String[i] != '\0'; i++)
	{
		OLED_ShowChar(Line, Column + i, String[i]);
	}
}

/**
  * @brief  OLED次方函数
  * @retval 返回值等于X的Y次方
  */
uint32_t OLED_Pow(uint32_t X, uint32_t Y)
{
	uint32_t Result = 1;
	while (Y--)
	{
		Result *= X;
	}
	return Result;
}

/**
  * @brief  OLED显示数字（十进制，正数）
  * @param  Line 起始行位置，范围：1~4
  * @param  Column 起始列位置，范围：1~16
  * @param  Number 要显示的数字，范围：0~4294967295
  * @param  Length 要显示数字的长度，范围：1~10
  * @retval 无
  */
void OLED_ShowNum(uint8_t Line, uint8_t Column, uint32_t Number, uint8_t Length)
{
	uint8_t i;
	for (i = 0; i < Length; i++)							
	{
		OLED_ShowChar(Line, Column + i, Number / OLED_Pow(10, Length - i - 1) % 10 + '0');
	}
}

/**
  * @brief  OLED显示数字（十进制，带符号数）
  * @param  Line 起始行位置，范围：1~4
  * @param  Column 起始列位置，范围：1~16
  * @param  Number 要显示的数字，范围：-2147483648~2147483647
  * @param  Length 要显示数字的长度，范围：1~10
  * @retval 无
  */
void OLED_ShowSignedNum(uint8_t Line, uint8_t Column, int32_t Number, uint8_t Length)
{
	uint8_t i;
	uint32_t Number1;
	if (Number >= 0)
	{
		OLED_ShowChar(Line, Column, '+');
		Number1 = Number;
	}
	else
	{
		OLED_ShowChar(Line, Column, '-');
		Number1 = -Number;
	}
	for (i = 0; i < Length; i++)							
	{
		OLED_ShowChar(Line, Column + i + 1, Number1 / OLED_Pow(10, Length - i - 1) % 10 + '0');
	}
}

/**
  * @brief  OLED显示数字（十六进制，正数）
  * @param  Line 起始行位置，范围：1~4
  * @param  Column 起始列位置，范围：1~16
  * @param  Number 要显示的数字，范围：0~0xFFFFFFFF
  * @param  Length 要显示数字的长度，范围：1~8
  * @retval 无
  */
void OLED_ShowHexNum(uint8_t Line, uint8_t Column, uint32_t Number, uint8_t Length)
{
	uint8_t i, SingleNumber;
	for (i = 0; i < Length; i++)							
	{
		SingleNumber = Number / OLED_Pow(16, Length - i - 1) % 16;
		if (SingleNumber < 10)
		{
			OLED_ShowChar(Line, Column + i, SingleNumber + '0');
		}
		else
		{
			OLED_ShowChar(Line, Column + i, SingleNumber - 10 + 'A');
		}
	}
}

/**
  * @brief  OLED显示数字（二进制，正数）
  * @param  Line 起始行位置，范围：1~4
  * @param  Column 起始列位置，范围：1~16
  * @param  Number 要显示的数字，范围：0~1111 1111 1111 1111
  * @param  Length 要显示数字的长度，范围：1~16
  * @retval 无
  */
void OLED_ShowBinNum(uint8_t Line, uint8_t Column, uint32_t Number, uint8_t Length)
{
	uint8_t i;
	for (i = 0; i < Length; i++)							
	{
		OLED_ShowChar(Line, Column + i, Number / OLED_Pow(2, Length - i - 1) % 2 + '0');
	}
}

/**
  * @brief  OLED初始化
  * @param  无
  * @retval 无
  */
void OLED_Init(void)
{
	uint32_t i, j;
	
	for (i = 0; i < 1000; i++)			//上电延时
	{
		for (j = 0; j < 1000; j++);
	}
	
	OLED_I2C_Init();			//端口初始化
	
	OLED_WriteCommand(0xAE);	//关闭显示
	
	OLED_WriteCommand(0xD5);	//设置显示时钟分频比/振荡器频率
	OLED_WriteCommand(0x80);
	
	OLED_WriteCommand(0xA8);	//设置多路复用率
	OLED_WriteCommand(0x3F);
	
	OLED_WriteCommand(0xD3);	//设置显示偏移
	OLED_WriteCommand(0x00);
	
	OLED_WriteCommand(0x40);	//设置显示开始行
	
	OLED_WriteCommand(0xA1);	//设置左右方向，0xA1正常 0xA0左右反置
	
	OLED_WriteCommand(0xC8);	//设置上下方向，0xC8正常 0xC0上下反置

	OLED_WriteCommand(0xDA);	//设置COM引脚硬件配置
	OLED_WriteCommand(0x12);
	
	OLED_WriteCommand(0x81);	//设置对比度控制
	OLED_WriteCommand(0xCF);

	OLED_WriteCommand(0xD9);	//设置预充电周期
	OLED_WriteCommand(0xF1);

	OLED_WriteCommand(0xDB);	//设置VCOMH取消选择级别
	OLED_WriteCommand(0x30);

	OLED_WriteCommand(0xA4);	//设置整个显示打开/关闭

	OLED_WriteCommand(0xA6);	//设置正常/倒转显示

	OLED_WriteCommand(0x8D);	//设置充电泵
	OLED_WriteCommand(0x14);

	OLED_WriteCommand(0xAF);	//开启显示
		
	OLED_Clear();				//OLED清屏
}

//oled模块的头文件
#ifndef __OLED_H
#define __OLED_H

void OLED_Init(void);
void OLED_Clear(void);
void OLED_ShowChar(uint8_t Line, uint8_t Column, char Char);
void OLED_ShowString(uint8_t Line, uint8_t Column, char *String);
void OLED_ShowNum(uint8_t Line, uint8_t Column, uint32_t Number, uint8_t Length);
void OLED_ShowSignedNum(uint8_t Line, uint8_t Column, int32_t Number, uint8_t Length);
void OLED_ShowHexNum(uint8_t Line, uint8_t Column, uint32_t Number, uint8_t Length);
void OLED_ShowBinNum(uint8_t Line, uint8_t Column, uint32_t Number, uint8_t Length);

#endif

//oled模块的取模文件
#ifndef __OLED_FONT_H
#define __OLED_FONT_H

/*OLED字模库，宽8像素，高16像素*/
const uint8_t OLED_F8x16[][16]=
{
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//  0
	
	0x00,0x00,0x00,0xF8,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x33,0x30,0x00,0x00,0x00,//! 1
	
	0x00,0x10,0x0C,0x06,0x10,0x0C,0x06,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//" 2
	
	0x40,0xC0,0x78,0x40,0xC0,0x78,0x40,0x00,
	0x04,0x3F,0x04,0x04,0x3F,0x04,0x04,0x00,//# 3
	
	0x00,0x70,0x88,0xFC,0x08,0x30,0x00,0x00,
	0x00,0x18,0x20,0xFF,0x21,0x1E,0x00,0x00,//$ 4
	
	0xF0,0x08,0xF0,0x00,0xE0,0x18,0x00,0x00,
	0x00,0x21,0x1C,0x03,0x1E,0x21,0x1E,0x00,//% 5
	
	0x00,0xF0,0x08,0x88,0x70,0x00,0x00,0x00,
	0x1E,0x21,0x23,0x24,0x19,0x27,0x21,0x10,//& 6
	
	0x10,0x16,0x0E,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//' 7
	
	0x00,0x00,0x00,0xE0,0x18,0x04,0x02,0x00,
	0x00,0x00,0x00,0x07,0x18,0x20,0x40,0x00,//( 8
	
	0x00,0x02,0x04,0x18,0xE0,0x00,0x00,0x00,
	0x00,0x40,0x20,0x18,0x07,0x00,0x00,0x00,//) 9
	
	0x40,0x40,0x80,0xF0,0x80,0x40,0x40,0x00,
	0x02,0x02,0x01,0x0F,0x01,0x02,0x02,0x00,//* 10
	
	0x00,0x00,0x00,0xF0,0x00,0x00,0x00,0x00,
	0x01,0x01,0x01,0x1F,0x01,0x01,0x01,0x00,//+ 11
	
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x80,0xB0,0x70,0x00,0x00,0x00,0x00,0x00,//, 12
	
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x01,0x01,0x01,0x01,0x01,0x01,0x01,//- 13
	
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x30,0x30,0x00,0x00,0x00,0x00,0x00,//. 14
	
	0x00,0x00,0x00,0x00,0x80,0x60,0x18,0x04,
	0x00,0x60,0x18,0x06,0x01,0x00,0x00,0x00,/// 15
	
	0x00,0xE0,0x10,0x08,0x08,0x10,0xE0,0x00,
	0x00,0x0F,0x10,0x20,0x20,0x10,0x0F,0x00,//0 16
	
	0x00,0x10,0x10,0xF8,0x00,0x00,0x00,0x00,
	0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//1 17
	
	0x00,0x70,0x08,0x08,0x08,0x88,0x70,0x00,
	0x00,0x30,0x28,0x24,0x22,0x21,0x30,0x00,//2 18
	
	0x00,0x30,0x08,0x88,0x88,0x48,0x30,0x00,
	0x00,0x18,0x20,0x20,0x20,0x11,0x0E,0x00,//3 19
	
	0x00,0x00,0xC0,0x20,0x10,0xF8,0x00,0x00,
	0x00,0x07,0x04,0x24,0x24,0x3F,0x24,0x00,//4 20
	
	0x00,0xF8,0x08,0x88,0x88,0x08,0x08,0x00,
	0x00,0x19,0x21,0x20,0x20,0x11,0x0E,0x00,//5 21
	
	0x00,0xE0,0x10,0x88,0x88,0x18,0x00,0x00,
	0x00,0x0F,0x11,0x20,0x20,0x11,0x0E,0x00,//6 22
	
	0x00,0x38,0x08,0x08,0xC8,0x38,0x08,0x00,
	0x00,0x00,0x00,0x3F,0x00,0x00,0x00,0x00,//7 23
	
	0x00,0x70,0x88,0x08,0x08,0x88,0x70,0x00,
	0x00,0x1C,0x22,0x21,0x21,0x22,0x1C,0x00,//8 24
	
	0x00,0xE0,0x10,0x08,0x08,0x10,0xE0,0x00,
	0x00,0x00,0x31,0x22,0x22,0x11,0x0F,0x00,//9 25
	
	0x00,0x00,0x00,0xC0,0xC0,0x00,0x00,0x00,
	0x00,0x00,0x00,0x30,0x30,0x00,0x00,0x00,//: 26
	
	0x00,0x00,0x00,0x80,0x00,0x00,0x00,0x00,
	0x00,0x00,0x80,0x60,0x00,0x00,0x00,0x00,//; 27
	
	0x00,0x00,0x80,0x40,0x20,0x10,0x08,0x00,
	0x00,0x01,0x02,0x04,0x08,0x10,0x20,0x00,//< 28
	
	0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x00,
	0x04,0x04,0x04,0x04,0x04,0x04,0x04,0x00,//= 29
	
	0x00,0x08,0x10,0x20,0x40,0x80,0x00,0x00,
	0x00,0x20,0x10,0x08,0x04,0x02,0x01,0x00,//> 30
	
	0x00,0x70,0x48,0x08,0x08,0x08,0xF0,0x00,
	0x00,0x00,0x00,0x30,0x36,0x01,0x00,0x00,//? 31
	
	0xC0,0x30,0xC8,0x28,0xE8,0x10,0xE0,0x00,
	0x07,0x18,0x27,0x24,0x23,0x14,0x0B,0x00,//@ 32
	
	0x00,0x00,0xC0,0x38,0xE0,0x00,0x00,0x00,
	0x20,0x3C,0x23,0x02,0x02,0x27,0x38,0x20,//A 33
	
	0x08,0xF8,0x88,0x88,0x88,0x70,0x00,0x00,
	0x20,0x3F,0x20,0x20,0x20,0x11,0x0E,0x00,//B 34
	
	0xC0,0x30,0x08,0x08,0x08,0x08,0x38,0x00,
	0x07,0x18,0x20,0x20,0x20,0x10,0x08,0x00,//C 35
	
	0x08,0xF8,0x08,0x08,0x08,0x10,0xE0,0x00,
	0x20,0x3F,0x20,0x20,0x20,0x10,0x0F,0x00,//D 36
	
	0x08,0xF8,0x88,0x88,0xE8,0x08,0x10,0x00,
	0x20,0x3F,0x20,0x20,0x23,0x20,0x18,0x00,//E 37
	
	0x08,0xF8,0x88,0x88,0xE8,0x08,0x10,0x00,
	0x20,0x3F,0x20,0x00,0x03,0x00,0x00,0x00,//F 38
	
	0xC0,0x30,0x08,0x08,0x08,0x38,0x00,0x00,
	0x07,0x18,0x20,0x20,0x22,0x1E,0x02,0x00,//G 39
	
	0x08,0xF8,0x08,0x00,0x00,0x08,0xF8,0x08,
	0x20,0x3F,0x21,0x01,0x01,0x21,0x3F,0x20,//H 40
	
	0x00,0x08,0x08,0xF8,0x08,0x08,0x00,0x00,
	0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//I 41
	
	0x00,0x00,0x08,0x08,0xF8,0x08,0x08,0x00,
	0xC0,0x80,0x80,0x80,0x7F,0x00,0x00,0x00,//J 42
	
	0x08,0xF8,0x88,0xC0,0x28,0x18,0x08,0x00,
	0x20,0x3F,0x20,0x01,0x26,0x38,0x20,0x00,//K 43
	
	0x08,0xF8,0x08,0x00,0x00,0x00,0x00,0x00,
	0x20,0x3F,0x20,0x20,0x20,0x20,0x30,0x00,//L 44
	
	0x08,0xF8,0xF8,0x00,0xF8,0xF8,0x08,0x00,
	0x20,0x3F,0x00,0x3F,0x00,0x3F,0x20,0x00,//M 45
	
	0x08,0xF8,0x30,0xC0,0x00,0x08,0xF8,0x08,
	0x20,0x3F,0x20,0x00,0x07,0x18,0x3F,0x00,//N 46
	
	0xE0,0x10,0x08,0x08,0x08,0x10,0xE0,0x00,
	0x0F,0x10,0x20,0x20,0x20,0x10,0x0F,0x00,//O 47
	
	0x08,0xF8,0x08,0x08,0x08,0x08,0xF0,0x00,
	0x20,0x3F,0x21,0x01,0x01,0x01,0x00,0x00,//P 48
	
	0xE0,0x10,0x08,0x08,0x08,0x10,0xE0,0x00,
	0x0F,0x18,0x24,0x24,0x38,0x50,0x4F,0x00,//Q 49
	
	0x08,0xF8,0x88,0x88,0x88,0x88,0x70,0x00,
	0x20,0x3F,0x20,0x00,0x03,0x0C,0x30,0x20,//R 50
	
	0x00,0x70,0x88,0x08,0x08,0x08,0x38,0x00,
	0x00,0x38,0x20,0x21,0x21,0x22,0x1C,0x00,//S 51
	
	0x18,0x08,0x08,0xF8,0x08,0x08,0x18,0x00,
	0x00,0x00,0x20,0x3F,0x20,0x00,0x00,0x00,//T 52
	
	0x08,0xF8,0x08,0x00,0x00,0x08,0xF8,0x08,
	0x00,0x1F,0x20,0x20,0x20,0x20,0x1F,0x00,//U 53
	
	0x08,0x78,0x88,0x00,0x00,0xC8,0x38,0x08,
	0x00,0x00,0x07,0x38,0x0E,0x01,0x00,0x00,//V 54
	
	0xF8,0x08,0x00,0xF8,0x00,0x08,0xF8,0x00,
	0x03,0x3C,0x07,0x00,0x07,0x3C,0x03,0x00,//W 55
	
	0x08,0x18,0x68,0x80,0x80,0x68,0x18,0x08,
	0x20,0x30,0x2C,0x03,0x03,0x2C,0x30,0x20,//X 56
	
	0x08,0x38,0xC8,0x00,0xC8,0x38,0x08,0x00,
	0x00,0x00,0x20,0x3F,0x20,0x00,0x00,0x00,//Y 57
	
	0x10,0x08,0x08,0x08,0xC8,0x38,0x08,0x00,
	0x20,0x38,0x26,0x21,0x20,0x20,0x18,0x00,//Z 58
	
	0x00,0x00,0x00,0xFE,0x02,0x02,0x02,0x00,
	0x00,0x00,0x00,0x7F,0x40,0x40,0x40,0x00,//[ 59
	
	0x00,0x0C,0x30,0xC0,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x01,0x06,0x38,0xC0,0x00,//\ 60
	
	0x00,0x02,0x02,0x02,0xFE,0x00,0x00,0x00,
	0x00,0x40,0x40,0x40,0x7F,0x00,0x00,0x00,//] 61
	
	0x00,0x00,0x04,0x02,0x02,0x02,0x04,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//^ 62
	
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,//_ 63
	
	0x00,0x02,0x02,0x04,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//` 64
	
	0x00,0x00,0x80,0x80,0x80,0x80,0x00,0x00,
	0x00,0x19,0x24,0x22,0x22,0x22,0x3F,0x20,//a 65
	
	0x08,0xF8,0x00,0x80,0x80,0x00,0x00,0x00,
	0x00,0x3F,0x11,0x20,0x20,0x11,0x0E,0x00,//b 66
	
	0x00,0x00,0x00,0x80,0x80,0x80,0x00,0x00,
	0x00,0x0E,0x11,0x20,0x20,0x20,0x11,0x00,//c 67
	
	0x00,0x00,0x00,0x80,0x80,0x88,0xF8,0x00,
	0x00,0x0E,0x11,0x20,0x20,0x10,0x3F,0x20,//d 68
	
	0x00,0x00,0x80,0x80,0x80,0x80,0x00,0x00,
	0x00,0x1F,0x22,0x22,0x22,0x22,0x13,0x00,//e 69
	
	0x00,0x80,0x80,0xF0,0x88,0x88,0x88,0x18,
	0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//f 70
	
	0x00,0x00,0x80,0x80,0x80,0x80,0x80,0x00,
	0x00,0x6B,0x94,0x94,0x94,0x93,0x60,0x00,//g 71
	
	0x08,0xF8,0x00,0x80,0x80,0x80,0x00,0x00,
	0x20,0x3F,0x21,0x00,0x00,0x20,0x3F,0x20,//h 72
	
	0x00,0x80,0x98,0x98,0x00,0x00,0x00,0x00,
	0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//i 73
	
	0x00,0x00,0x00,0x80,0x98,0x98,0x00,0x00,
	0x00,0xC0,0x80,0x80,0x80,0x7F,0x00,0x00,//j 74
	
	0x08,0xF8,0x00,0x00,0x80,0x80,0x80,0x00,
	0x20,0x3F,0x24,0x02,0x2D,0x30,0x20,0x00,//k 75
	
	0x00,0x08,0x08,0xF8,0x00,0x00,0x00,0x00,
	0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//l 76
	
	0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x00,
	0x20,0x3F,0x20,0x00,0x3F,0x20,0x00,0x3F,//m 77
	
	0x80,0x80,0x00,0x80,0x80,0x80,0x00,0x00,
	0x20,0x3F,0x21,0x00,0x00,0x20,0x3F,0x20,//n 78
	
	0x00,0x00,0x80,0x80,0x80,0x80,0x00,0x00,
	0x00,0x1F,0x20,0x20,0x20,0x20,0x1F,0x00,//o 79
	
	0x80,0x80,0x00,0x80,0x80,0x00,0x00,0x00,
	0x80,0xFF,0xA1,0x20,0x20,0x11,0x0E,0x00,//p 80
	
	0x00,0x00,0x00,0x80,0x80,0x80,0x80,0x00,
	0x00,0x0E,0x11,0x20,0x20,0xA0,0xFF,0x80,//q 81
	
	0x80,0x80,0x80,0x00,0x80,0x80,0x80,0x00,
	0x20,0x20,0x3F,0x21,0x20,0x00,0x01,0x00,//r 82
	
	0x00,0x00,0x80,0x80,0x80,0x80,0x80,0x00,
	0x00,0x33,0x24,0x24,0x24,0x24,0x19,0x00,//s 83
	
	0x00,0x80,0x80,0xE0,0x80,0x80,0x00,0x00,
	0x00,0x00,0x00,0x1F,0x20,0x20,0x00,0x00,//t 84
	
	0x80,0x80,0x00,0x00,0x00,0x80,0x80,0x00,
	0x00,0x1F,0x20,0x20,0x20,0x10,0x3F,0x20,//u 85
	
	0x80,0x80,0x80,0x00,0x00,0x80,0x80,0x80,
	0x00,0x01,0x0E,0x30,0x08,0x06,0x01,0x00,//v 86
	
	0x80,0x80,0x00,0x80,0x00,0x80,0x80,0x80,
	0x0F,0x30,0x0C,0x03,0x0C,0x30,0x0F,0x00,//w 87
	
	0x00,0x80,0x80,0x00,0x80,0x80,0x80,0x00,
	0x00,0x20,0x31,0x2E,0x0E,0x31,0x20,0x00,//x 88
	
	0x80,0x80,0x80,0x00,0x00,0x80,0x80,0x80,
	0x80,0x81,0x8E,0x70,0x18,0x06,0x01,0x00,//y 89
	
	0x00,0x80,0x80,0x80,0x80,0x80,0x80,0x00,
	0x00,0x21,0x30,0x2C,0x22,0x21,0x30,0x00,//z 90
	
	0x00,0x00,0x00,0x00,0x80,0x7C,0x02,0x02,
	0x00,0x00,0x00,0x00,0x00,0x3F,0x40,0x40,//{ 91
	
	0x00,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,//| 92
	
	0x00,0x02,0x02,0x7C,0x80,0x00,0x00,0x00,
	0x00,0x40,0x40,0x3F,0x00,0x00,0x00,0x00,//} 93
	
	0x00,0x06,0x01,0x01,0x02,0x02,0x04,0x04,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//~ 94
};

#endif

HC-SR04超声波模块：

//超声波模块的源文件
#include "stm32f10x.h"
#include "Delay.h"

#define Echo GPIO_Pin_4		//HC-SR04模块的Echo脚接GPIOB6
#define Trig GPIO_Pin_5		//HC-SR04模块的Trig脚接GPIOB5

uint64_t time=0;			//声明变量，用来计时
uint64_t time_end=0;		//声明变量，存储回波信号时间

void HC_SR04_Init(void)
{
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE);	//启用GPIOB的外设时钟	
	GPIO_InitTypeDef GPIO_InitStructure;					//定义结构体
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;		//设置GPIO口为推挽输出
	GPIO_InitStructure.GPIO_Pin = Trig;						//设置GPIO口5
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;		//设置GPIO口速度50Mhz
	GPIO_Init(GPIOB,&GPIO_InitStructure);					//初始化GPIOB
	
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD;			//设置GPIO口为下拉输入模式
	GPIO_InitStructure.GPIO_Pin = Echo;						//设置GPIO口6
	GPIO_Init(GPIOB,&GPIO_InitStructure);					//初始化GPIOB
	GPIO_WriteBit(GPIOB,GPIO_Pin_5,0);						//输出低电平
	Delay_us(15);											//延时15微秒
}

int16_t sonar_mm(void)									//测距并返回单位为毫米的距离结果
{
	uint32_t Distance,Distance_mm = 0;
	GPIO_WriteBit(GPIOB,Trig,1);						//输出高电平
	Delay_us(15);										//延时15微秒
	GPIO_WriteBit(GPIOB,Trig,0);						//输出低电平
	while(GPIO_ReadInputDataBit(GPIOB,Echo)==0);		//等待低电平结束
	time=0;												//计时清零
	while(GPIO_ReadInputDataBit(GPIOB,Echo)==1);		//等待高电平结束
	time_end=time;										//记录结束时的时间
	if(time_end/100<38)									//判断是否小于38毫秒，大于38毫秒的就是超时，直接调到下面返回0
	{
		Distance=(time_end*346)/2;						//计算距离，25°C空气中的音速为346m/s
		Distance_mm=Distance/100;						//因为上面的time_end的单位是10微秒，所以要得出单位为毫米的距离结果，还得除以100
	}
	return Distance_mm;									//返回测距结果
}

float sonar(void)										//测距并返回单位为米的距离结果
{
	uint32_t Distance,Distance_mm = 0;
	float Distance_m=0;
	GPIO_WriteBit(GPIOB,Trig,1);					//输出高电平
	Delay_us(15);
	GPIO_WriteBit(GPIOB,Trig,0);					//输出低电平
	while(GPIO_ReadInputDataBit(GPIOB,Echo)==0);
	time=0;
	while(GPIO_ReadInputDataBit(GPIOB,Echo)==1);
	time_end=time;
	if(time_end/100<38)
	{
		Distance=(time_end*346)/2;
		Distance_mm=Distance/100;
		Distance_m=Distance_mm/1000;
	}
	return Distance_m;
}

void TIM3_IRQHandler(void)			//更新中断函数，用来计时，每10微秒变量time加1
{
	if (TIM_GetITStatus(TIM3, TIM_IT_Update) == SET)		//获取TIM3定时器的更新中断标志位
	{
		time++;
		TIM_ClearITPendingBit(TIM3, TIM_IT_Update);			//清除更新中断标志位
	}
}

//超声波模块的头文件
#ifndef __HCSR04_H
#define __HCSR04_H

void HC_SR04_Init(void);
int16_t sonar_mm(void);
float sonar(void);

#endif

时间函数模块：

//时间函数模块源文件
#include "stm32f10x.h"                  // Device header

void Timer_Init(void)
{
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);		//启用TIM3时钟

	TIM_InternalClockConfig(TIM3);								//设置TIM3使用内部时钟
	
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;			//定义结构体，配置定时器
	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;	//设置1分频（不分频）
	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;	//设置计数模式为向上计数
	TIM_TimeBaseInitStructure.TIM_Period = 10 - 1;			//设置最大计数值，达到最大值触发更新事件，因为从0开始计数，所以计数10次是10-1,每10微秒触发一次
	TIM_TimeBaseInitStructure.TIM_Prescaler = 72 - 1;			//设置时钟预分频，72-1就是每 时钟频率(72Mhz)/72=1000000 个时钟周期计数器加1,每1微秒+1
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;		//重复计数器（高级定时器才有，所以设置0）
	TIM_TimeBaseInit(TIM3, &TIM_TimeBaseInitStructure);			//初始化TIM3定时器
	
	TIM_ClearFlag(TIM3, TIM_FLAG_Update);			//清除更新中断标志位
	TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);		//开启更新中断
	
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);				//设置中断优先级分组
	
	NVIC_InitTypeDef NVIC_InitStructure;						//定义结构体，配置中断优先级
	NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;				//指定中断通道
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;				//中断使能
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;	//设置抢占优先级
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;			//设置响应优先级
	NVIC_Init(&NVIC_InitStructure);								// https://blog.zeruns.tech
	
	TIM_Cmd(TIM3, ENABLE);							//开启定时器
}

/*
void TIM3_IRQHandler(void)			//更新中断函数
{
	if (TIM_GetITStatus(TIM3, TIM_IT_Update) == SET)		//获取TIM3定时器的更新中断标志位
	{
		
		TIM_ClearITPendingBit(TIM3, TIM_IT_Update);			//清除更新中断标志位
	}
}*/

//时间函数模块头文件
#ifndef __TIMER_H
#define __TIMER_H

void Timer_Init(void);

#endif

蜂鸣器模块：

//蜂鸣器模块的源文件
#include "stm32f10x.h"                  // Device header
void Buzzer_Init(void)
{
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);  // 打开 GPIOA 时钟

    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_14;  // PA0 引脚
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;  // 推挽输出模式
    GPIO_Init(GPIOB, &GPIO_InitStructure);
	GPIO_ResetBits (GPIOB,GPIO_Pin_14);
}
void Buzzer_ON(void)
{
	GPIO_ResetBits(GPIOB,GPIO_Pin_14);
}
void Buzzer_OFF(void)
{
	GPIO_SetBits(GPIOB,GPIO_Pin_14);
}
void Buzzer_Turn(void)
{
	if(GPIO_ReadOutputDataBit(GPIOB,GPIO_Pin_14)==0)
	{
		GPIO_SetBits(GPIOB,GPIO_Pin_14);
	}
	else
	{
		GPIO_ResetBits(GPIOB,GPIO_Pin_14);
	}
}

//蜂鸣器模块的头文件
#ifndef __BUZZER_H
#define __BUZZER_H

void Buzzer_Init(void);
void Buzzer_ON(void);
void Buzzer_OFF(void);
void Buzzer_Turn(void);


#endif

HC-SR04超声波传感器实现

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