哪位大侠写过msp430f149控制DHT11温室读传感器的串口显示程序,我调了好久总是不能显示数据 ?不知道什么原因?高手帮忙啊,不胜感激之至!!
串口程序;
#include "usart.h"
struct DHT_data
{
unsigned char DH_H; //湿度整数
unsigned char DH_L; //湿度小数
unsigned char T_H; //温度整数
unsigned char T_L; //温度小数
unsigned char Checksum; //校验和
}DHT_data;
void Usart_Init(void)
{
P3SEL |= 0x30; // P3.4,5 = USCI_A0 TXD/RXD
ME1 |= UTXE0 + URXE0; // 使能USART0收发
UCTL0 |= CHAR; // 8-bit character
UTCTL0 |= SSEL0; // UCLK = ACLK
UBR00 = 0x03; // 32k/9600 - 3.41
UBR10 = 0x00; //
UMCTL0 = 0x4A; // Modulation
UCTL0 &= ~SWRST; // 初始化UART0状态机
IE1 |= URXIE0; // 使能接收中断
_EINT();
}
void TXString( char* string, int length )//发送字符串
{
int pointer;
for( pointer = 0; pointer < length; pointer++)
{
volatile int i;
TXBUF0 = string[pointer];
while (!(IFG1 & UTXIFG0));
}
}
void my_putchar(unsigned char ch)
{
TXBUF0=(unsigned char) ch;
while (!(IFG1 & UTXIFG0));
}
void my_puts(unsigned char *s)
{
while(*s++)
my_putchar(*s);
}
DHT11 程序:
#include "dht11.h"
unsigned char humidity, temperature, check_sum ;
/**********************************************/
/* 开始 DHT11 温湿度计 */
/* 输入:无 */
/* 输出:应答标志 0:应答失败 1:应答成功 */
/**********************************************/
unsigned char start_DHT11(void)
{
unsigned char time=0;
DHT11_OUTPUT;
DHT11_H;
DHT11_L; //拉低18ms以上
delay_ms(30);
DHT11_H;
delay_us(40);
DHT11_INPUT;
// temp=DHT11_IN;
if(!DHT11_IN)
{
while(!(DHT11_IN)&&time++);
while(DHT11_IN&&time++);
return 1;
}
else
{
return 0;
}
}
void read_DHT11(void)
{
unsigned char tem[5]; //读到的五个数
unsigned char i, j, temp;
for(i = 0; i < 5; i ++)
{
tem
= 0;
for(j = 0; j < 8; j ++)
{
tem *= 2; //不可用tem << 1 否则不移位
temp = 2; //
delay_us(20); //先延20uS 再检查30uS
while((!DHT11_IN) && temp ++)//避免死等
if(temp == 2)
break;
delay_us(32); //高电平长于26-28uS为1否为0
temp = 2;
if(DHT11_IN)
{
while(DHT11_IN && temp ++) //当为1时等到低电平再进入下次循环。
if(temp == 2)
break;
tem |= 0x01;
}
delay_us(5);
}
humidity = tem[0];
temperature = tem[2];
check_sum = tem[4];
}
}
主函数main:
#include <msp430x14x.h>
#include "dht11.h"
#include "usart.h"
const char word1[] = {"
**DHT11 TEST**
"};
const char word2[] = {"
**DHT11 CHECK**
"};
const char word3[] = {"
**DHT11 NOT EXIST**
"};
void display(void);
void main( void )
{
WDTCTL=WDTPW+WDTHOLD; //关看门狗
Usart_Init();
P2DIR |=BIT7;//点亮LED0 RED
P2OUT &=~BIT7;
P2DIR |=BIT5;//点亮LED1 GREEN
TXString((char*)word1, sizeof word1);
delay_ms(1000);
delay_ms(1000);
while(1)
{
if(start_DHT11()) //如果应答成功
{
P2OUT |=BIT7;
TXString((char*)word2, sizeof word2);
read_DHT11(); //读温湿度
display(); //则显示温湿度数值
}
else
{
P2OUT &=~BIT7;
TXString((char*)word3, sizeof word3);
}
P2OUT |=BIT5;
delay_ms(1000);
P2OUT&=~BIT5;
delay_ms(1000);
}
}
void display(void)
{
unsigned char table[11];
table[0]=humidity/0x10+0x30;//湿度
table[1]=humidity%0x10+0x30;
table[2]='%';
table[3]='R';
table[4]='H';
table[5]=' ';
table[6]=temperature/0X10+0x30;//温度
table[7]=temperature%0X10+0x30;
table[8]='C';
table[9]='
';
table[10]='
';
TXString((char*)table, sizeof table);
}
需要的头文件:
usart.h
#ifndef _USART_H_
#define _USART_H_
#include"msp430x14x.h"
void Usart_Init(void);
void TXString( char* string, int length );//发送字符串
void my_putchar(unsigned char ch);
void my_puts(unsigned char *s);
#endif
dht11.h
#ifndef _DHT11_H_
#define _DHT11_H_
#include "msp430x14x.h"
#define CPU (12000000)
#define delay_us(x) (__delay_cycles((double)x*CPU/1000000.0))
#define delay_ms(x) (__delay_cycles((double)x*CPU/1000.0))
#define DHT11_OUTPUT P1DIR|=BIT0
#define DHT11_INPUT P1DIR&=~BIT0
#define DHT11_H P1OUT|=BIT0
#define DHT11_L P1OUT&=~BIT0
#define DHT11_IN (P1IN&BIT0)
extern unsigned char humidity, temperature, check_sum ;
unsigned char start_DHT11(void);
void read_DHT11(void);
#endif
此帖出自小平头技术问答
一周热门 更多>