基于 W80x 实现 DS18B20 驱动. 代码如下;

include "wm_include. h"

include "temper. h"

define DS18B20_SKIP_ROM 0xCC

define DS18B20_CONVERT_T 0x44

define DS18B20_READ_SCRATCHPAD 0xBE

static void t_Delay_us (uint16_t num)
{

uint32_t i; 
for (i=0; i " (80*num) ; i++) 
{
    __NOP () ; 
}
    

}

static uint8_t DS18B20_IN (void)
{

tls_gpio_cfg (WM_IO_PB_00,  WM_GPIO_DIR_INPUT,  WM_GPIO_ATTR_FLOATING) ; 
return tls_bitband_read (HR_GPIOB_DATA, WM_IO_PB_00-16) ;                   //读取引脚电平

}

static uint8_t DS18B20_LOW (void)
{

// tls_gpio_cfg (WM_IO_PB_00,  WM_GPIO_DIR_OUTPUT,  WM_GPIO_ATTR_FLOATING) ; 
tls_bitband_write (HR_GPIOB_DATA,  WM_IO_PB_00-16,  0) ; 

}

static uint8_t DS18B20_HIGH (void)
{

// tls_gpio_cfg (WM_IO_PB_00,  WM_GPIO_DIR_OUTPUT,  WM_GPIO_ATTR_FLOATING) ; 
tls_bitband_write (HR_GPIOB_DATA,  WM_IO_PB_00-16,  1) ; 

}

static void set_gpio (void)
{

tls_gpio_cfg (WM_IO_PB_00,  WM_GPIO_DIR_OUTPUT,  WM_GPIO_ATTR_FLOATING) ; 

}

static uint8_t DS18B20_Init (void)
{

uint8_t AckBit; 

DS18B20_LOW () ; 
t_Delay_us (480) ; 

DS18B20_HIGH () ; 
t_Delay_us (70) ; 

AckBit = DS18B20_IN () ; 
t_Delay_us (240) ; 
if (AckBit) 
{
    /*打印错误信息*/
    return 1; 
}

set_gpio () ; 
return 0; 

}

static void DS18B20_WriteBit (uint8_t bit)
{

DS18B20_LOW () ; 
t_Delay_us (10) ; 
if (bit) 
{
    DS18B20_HIGH () ; 
}
else
{
    DS18B20_LOW () ;     /*可省略*/
}
t_Delay_us (45) ; 
DS18B20_HIGH () ; 
t_Delay_us (2) ; 

}

static void DS18B20_WriteByte (uint8_t byte)
{

uint8_t i; 
for (i = 0;  i  " 8;  i++) 
{
    DS18B20_WriteBit (byte &  (0x01  " " i) ) ; 
}

}

uint8_t DS18B20_ReadBit (void)
{

uint8_t bit; 

DS18B20_LOW () ; 
t_Delay_us (5) ; 

DS18B20_HIGH () ; 
t_Delay_us (10) ; 

if (DS18B20_IN () ) 
{
    bit = 1; 
}
else
{
    bit = 0; 
}
t_Delay_us (45) ; 
set_gpio () ; 
return bit; 

}

void DS18B20_ReadByte (uint8_t *byte)
{

uint8_t i; 
for (i = 0;  i  " 8;  i++) 
{
    *byte " " = 1;  // 右移一位
    if (DS18B20_ReadBit () ) 
    {
        *byte |= 0x80;  // 设置最高位
    }
}

}

void DS18B20_Tem_Convert (void)
{

if (DS18B20_Init ()  == 0) 
{
    DS18B20_WriteByte (DS18B20_SKIP_ROM) ; 
    DS18B20_WriteByte (DS18B20_CONVERT_T) ; 
}
else
{
    /*打印错误信息*/
    printf ("%s DS18B20_Init ERROR\n", __FUNCTION__) ; 
}

}

void DS18B20_Read_Tem (float* tem)
{

uint16_t temValue; 
uint8_t tem_LSB,  tem_MSB; 
if (DS18B20_Init ()  == 0) 
{
    DS18B20_WriteByte (DS18B20_SKIP_ROM) ; 
    DS18B20_WriteByte (DS18B20_READ_SCRATCHPAD) ; 

    DS18B20_ReadByte (&tem_LSB) ; 
    DS18B20_ReadByte (&tem_MSB) ; 

    temValue =  (tem_MSB  " " 8)  | tem_LSB; 
    
    *tem =  (float) temValue / 16; 
}
else
{
    /*打印错误信息*/
    printf ("%s DS18B20_Init ERROR\n", __FUNCTION__) ; 
}

}

define TEMP_TASK_PRORITY 3

define TEMP_TASK_STACK_SIZE 1024

static OS_STK TaskStk[TEMP_TASK_STACK_SIZE/4];

void user_temp_task (void)
{

float temp=0; 
uint8_t time=10; 
uint8_t flag=0; 
uint8_t AckBit; 
printf ("%s %d \n", __FUNCTION__, __LINE__) ; 
set_gpio () ; 
// tls_gpio_cfg (WM_IO_PA_04,  WM_GPIO_DIR_OUTPUT,  WM_GPIO_ATTR_FLOATING) ; 
while  (1) 
{
    // tls_os_time_delay (2000) ; 
    DS18B20_Tem_Convert () ; 
    tls_os_time_delay (1000) ; 
    DS18B20_Read_Tem (&temp) ; 
    printf ("temp = %f \n", temp) ; 
    
}

}

void user_temp_task_create (void)
{

tls_os_task_create (NULL,  
                  "temperatrue", 
                   user_temp_task, 
                   NULL, 
                    (void *) TaskStk,           /* task's stack start address */
                   TEMP_TASK_STACK_SIZE,  /* task's stack size,  unit: byte */
                   TEMP_TASK_PRORITY, 
                   0) ; 

}