自行车多功能行车仪

自行车行车记录仪（非录像型）：

自行车简易行车记录仪功能演示及介绍

项目简介

本项目基于STC15W4K48S4单片机，通过读取DS1302、DS18B20、光敏电阻阻值以及霍尔传感器数值，完成测量时间、平均速度、温度、夜间行车自动开关灯、速度和骑行里程等功能。

项目功能

通过读取DS1302获取时间，精度为分钟。读取所得时间，用于计算平均速度、每分钟切换显示骑行时长与温度。
通过读取DS18B20温度传感器，读取温度数值并显示。
通过霍尔传感器与强力磁铁的配合，使用单片机内部时钟的定时功能，车轮滚动一圈触发一次中断，计算这段时间以内自行车行驶的平均速度。
通过读取光敏电阻与10K电阻对电源电压分压以后的电压的ADC转换值，实现在低亮度环境下的自动开关灯。同时搭配按键开关，可以在必要时手动关闭或开启行车灯。

原理解析（硬件说明）

工程采用3.3V可充电电池供电，使用6276电源管理芯片将3.3V电池输入电压转换为5V（实测5.02V）供电电压。
STC15W4K48S4单片机主控电路、光敏电阻ADC采样、OLED显示、按键以及DS18B20温度传感器读取电路
DS1302时钟读取电路。需要十分注意选择与DS1302负载电容匹配的晶振，否则难以起振或者起振具有随机性。我选择的是6皮法的。
最后是亮灯控制电路。注意在此电路中需要将Light引脚配置为推挽输出模式，否则灯光亮度大为下降。

main函数部分软件代码

#include   //all these codes should be used under the frequency of @12Mhz
#include 
#include "DS1302.h"
#include "OLED.h"
#include "18b20.h"
#include "ADC.h"

unsigned int timeflag=0;
unsigned int turn_count=0;
unsigned int light_read = 0;
unsigned int ji = 1000;
unsigned char hour;
unsigned char minute;
float time;
float average_speed = 0.00;
float total_distance = 0.00;
double time_count=0.00;
float temperature = 0.00;
bit light_flag = 0;
bit auto_light = 0;
bit key_light = 1;
sbit T_LED = P2^3;
sbit Light = P2^5;
DS1302_time tim;

/***codes declaration***/

void IO_set(void);
void inter_set(void);
void OLED_background(void);
void speed_display(void);
void Delay1ms(void);
/*** main codes****/

void main(void){
	IO_set();
	InitADC();
	inter_set();
	DS1302_Init();
	DS1302_SetTime();
	OLED_Init();
	OLED_CLS();
	OLED_background();
	speed_display();
	while(1){
		EA = 0;
        Init_DS18B20();
		
		temperature = ReadTemperature();
		
		DS1302_ReadTime(&amp;tim);
	    hour=tim.DS1302_Time[3];
	    minute=tim.DS1302_Time[4];
		time=(float)hour+(float)minute/60.0;
		
		if((minute%2) == 0){
			OLED_ShowASCII(86,6,"      "); //six spaces
			OLED_ShowChinese(64,6,9);
			OLED_ShowChinese(0,6,8);
			OLED_ShowChinese(16,6,9);
			displayfloat(temperature,32,6,4);
		}
		
		if((minute%2) == 1){
			OLED_ShowChinese(0,6,2);
			OLED_ShowChinese(16,6,3);
			OLED_ShowASCII(32,6,"    ");
			OLED_ShowNum(42,6,hour/10);
			OLED_ShowNum(50,6,hour%10);
			OLED_ShowNum(86,6,minute/10);
			OLED_ShowNum(94,6,minute%10);
			OLED_ShowASCII(64,6,"h  ");
			OLED_ShowASCII(103,6,"min");
		}
		light_read = GetADC(0x05);
		EA = 1;
		ji = 500;
		while(ji &gt; 0){
			
			if(light_read &lt;= 450 &amp;&amp; key_light){
				Light = 1;
				light_flag = 1;
				auto_light = 1;
			}

			if(T_LED == 0){
				Delay1ms();
				Delay1ms();
				if(T_LED == 0){
					light_flag = !light_flag;
					if(auto_light == 1){auto_light = 0; key_light = 0; Light = 0;}
					else if(light_flag == 1){Light = 1;}
					else if(light_flag == 0){Light = 0;}
				}
				while(T_LED == 0);
			}
			
			Delay1ms();
			ji--;
		}
	}
}

/****** detail codes*****/

void Delay1ms(void)	//@12.000MHz
{
	unsigned char i, j;

	i = 12;
	j = 169;
	do
	{
		while (--j);
	} while (--i);
}


void IO_set(void){
    P0M0 = 0x00; P0M1 = 0x00; 
    P1M0 = 0x00; P1M1 = 0x20; 
    P2M0 = 0x20; P2M1 = 0x00; 
    P3M0 = 0x00; P3M1 = 0x00; 
    P5M0 &amp;= ~0xef; P5M1 &amp;= ~0xef; 
}

void inter_set(void){
	Light=0;
	EX0=1;
	ET0=1;
	IT0=1;
	TH0=0x00;
	TL0=0x00;
	AUXR &amp;= 0x7f;
  TMOD = 0x00;   
	TR0=0;
	EA=0;
}

void OLED_background(void){
	OLED_ShowChinese(0,0,0);
	OLED_ShowChinese(16,0,1);
	OLED_ShowChinese(0,2,6);
	OLED_ShowChinese(16,2,7);
	OLED_ShowChinese(32,2,0);
	OLED_ShowChinese(48,2,1);
	OLED_ShowChinese(0,4,4);
	OLED_ShowChinese(16,4,5);
	OLED_ShowChinese(0,6,8);
	OLED_ShowChinese(16,6,9);
	displayfloat(0.000,48,0,6);
	OLED_ShowASCII(103,0,"m/s");
	OLED_ShowASCII(95,2,"km/h");
	OLED_ShowASCII(111,4,"km");
	OLED_ShowChinese(64,6,9);
}

void speed_display(void){
	if(time == 0){
		OLED_ShowASCII(63,2,"0.00");
	}
	if(time != 0){ 
		average_speed = ((float)turn_count/500.0)/time;
		displayfloat(average_speed,63,2,4);
	}
	displayfloat((float)turn_count/500.0,58,4,7);
}

/**** interrupt handler************/

void INT0_ISR (void) interrupt 0
{
	EA = 0;
	TR0=0;
	time_count=timeflag*0.065536+(double)(TH0*256+TL0)/1000000;
	timeflag=0;
	turn_count += 1;
	if(time_count != 0){
	  displayfloat((float)(2.00/time_count),48,0,6);
	}
	speed_display();
	TH0=0x00;
	TL0=0x00;
	TR0=1;
	EA = 1;
}

void Timer0_ISR (void) interrupt 1 
{
	TR0=0;
	timeflag=timeflag+1;
	TH0=0x00;
	TL0=0x00;
	TR0=1;
}