跪求大家帮忙新手上路谢谢！

只看该作者 · 2011-8-3 21:27

#include <C8051F060.h>                // SFR declarations
#include <stdio.h>

sfr16 RCAP2 = 0xCA;                // Timer2 capture/reload
sfr16 TMR2    = 0xCC;                // Timer2

#define BAUDRATE    56000          // Baud rate of UART in bps
#define SYSCLK    22118400L

sbit Trig = P3^0;
sbit Echo = P3^1;

void OSCILLATOR_Init (void);
void PORT_Init_UART0 (void);
void UART0_Init (void);
void PORT_Init (void);
void Delay(void);
void Timer0_Init(void);
void Count(void);
float s = 0;  //超声波的距离

//  主函数开始：关闭开门狗，系统时钟初始化，UART端口初始化，UART初始化，定时器0初始化,I/O端口的初始化以及超声波功能实现
void main (void)
{
SFRPAGE = CONFIG_PAGE;
WDTCN = 0xDE;                      // Disable watchdog timer
WDTCN = 0xAD;
OSCILLATOR_Init ();                // Initialize oscillator
PORT_Init_UART0 ();                // Initialize crossbar and GPIO
UART0_Init ();                   // Initialize UART0

Timer0_Init();
PORT_Init();
//while (1)
// {
// 超声波测距开始
// Trig = 1;
//    Delay ();    //至少10uS
// Trig = 0;
// while(!Echo);    //等待模块输出高电平
// TCON = 0x10;                      //启动计时器0
// while(Echo);    //等待模块输出低电平
// TCON &=~0x10;    //停止计时器，开始计算距离
// Count();
// PORT_Init_UART0 ();
printf("\ns=%f",s);  //串口输出所计算的距离
Delay();
//  }
}

void OSCILLATOR_Init (void)
{
int i;                            // Software timer
char SFRPAGE_SAVE = SFRPAGE;       // Save Current SFR page
SFRPAGE = CONFIG_PAGE;             // Set SFR page
OSCICN = 0x80;                   // Set internal oscillator to run
                                    // at its slowest frequency
CLKSEL = 0x00;                   // Select the internal osc. as
                                    // the SYSCLK source
// Initialize external crystal oscillator to use 22.1184 MHz crystal
OSCXCN = 0x67;                   // Enable external crystal osc.
for (i=0; i < 256; i++);          // Wait at least 1ms
while (!(OSCXCN & 0x80));          // Wait for crystal osc to settle
CLKSEL = 0x01;                   // Select external crystal as SYSCLK
                                    // source
SFRPAGE = SFRPAGE_SAVE;          // Restore SFRPAGE
}

void PORT_Init_UART0 (void)
{
char SFRPAGE_SAVE = SFRPAGE;       // Save Current SFR page
SFRPAGE = CONFIG_PAGE;             // Set SFR page

P3MDOUT=0x00;
P3  |=  0x03;    //配置P3.0 和 P3.1口为数字输入

P3MDOUT=0x01; //配置P3.0口为推挽输出
XBR0    = 0x04;                   // Enable UART0  将TX0和RX0引脚分别分配到P0.0和P0.1
XBR1    = 0x00;                   //内部资源不连接到端口1
XBR2    = 0x40;                   // Enable crossbar and weak pull-up

P0MDOUT |= 0x01;                   // Set TX pin to push-pull
P1MDOUT |= 0x40;                   // Set P1.6(LED) to push-pull
SFRPAGE = SFRPAGE_SAVE;          // Restore SFR page
}

void UART0_Init (void)
{
char SFRPAGE_SAVE;
SFRPAGE_SAVE = SFRPAGE;          // Preserve SFRPAGE
SFRPAGE = TMR2_PAGE;
TMR2CN = 0x00;                   // Timer in 16-bit auto-reload up timer
                                    // mode
TMR2CF = 0x08;                   // SYSCLK is time base; no output;
                                    // up count only
RCAP2 = - ((long) SYSCLK/BAUDRATE/16);
TMR2 = RCAP2;
TR2= 1;                            // Start Timer2
SFRPAGE = UART0_PAGE;
SCON0 = 0x50;                      // 8-bit variable baud rate;
                                    // 9th bit ignored; RX enabled
                                    // clear all flags
SSTA0 = 0x15;                      // Clear all flags; enable baud rate
                                    // doubler (not relevant for these
                                    // timers);
                                    // Use Timer2 as RX and TX baud rate
                                    // source;
TI0 = 1;                         // Indicate TX0 ready
SFRPAGE = SFRPAGE_SAVE;          // Restore SFRPAGE
}

//延时函数，具体延长多长时间，待定，至少10us
void Delay (void)
{
int x;
for(x = 0; x<100; x++);
}

//定时器0的初始化
void Timer0_Init(void)
{
char SFRPAGE_SAVE = SFRPAGE;       // Save Current SFR page
SFRPAGE = TIMER01_PAGE;          // Set SFR page

TH0 = 0x00;
TL0 = 0x00;                      //将定时器0设置为16位，计算时间时访问TH0和TL0这两个寄存器

TMOD = 0x01;                      // Timer0 in 16-bit mode
CKCON = 0x02;                      // Timer0 uses a 1:48 prescaler
ET0=0;                               // 将中断源关闭
SFRPAGE = SFRPAGE_SAVE;          // Restore SFR page
}

//计算超声波所测量距离
float count(void)
{
unsigned int time =0;
time = 256*TH0+TL0;
// printf("\n%u",time);
TH0  = 0x00;
TL0  = 0x00;
s = time*0.068;  //time0系统时钟单位CM
return s;
}

这个是利用C8051f60控制一个超声波模块的程序，但是我调了很久，都不能成功，请大家帮忙  谢谢！PS：单片机给超声波模块的Trig口一个高电平，计算Echo口相应的持续时间，就能计算出距离~