程序中。先拉低，然后将IO设成输入，用示波器看是否有复位脉冲。这样可以确保硬件没问题
1.时序是否正确
2.管脚是否有上拉电阻
STM32的DS18B20的测温
设置成开漏输出，外接上拉电阻，
没有说明芯片类型，如是F103直接设成开漏输出。
如是L152直接设成开漏输出。最好用寄操作存器保证时序。
有做上啦设置吗？
公司电脑 不太好弄 我有一个 STM32F030 读取DS18B20的程序 上传不上去
《DS18B20.c》
#include "stm32f0xx_hal.h"
#include "tim.h"
#include "DS18B20.h"
/*
微秒级延时用函数
*/
void Delay_us(uint16_t nus)
{
__HAL_TIM_SetCounter(&htim17, 0);
__HAL_TIM_ENABLE(&htim17);
while(__HAL_TIM_GetCounter(&htim17) < (48 * nus));
/* Disable the Peripheral */
__HAL_TIM_DISABLE(&htim17);
}
/*
复位DS18B20
*/
void DS18B20_Rst()
{
DS18B20_IO_OUT_SET(); //
HAL_GPIO_WritePin(DS18B20_GPIO_Port, DS18B20_Pin, GPIO_PIN_RESET); //拉低DQ
Delay_us(500);
//拉低500us
HAL_GPIO_WritePin(DS18B20_GPIO_Port, DS18B20_Pin, GPIO_PIN_SET); //DQ = 1
Delay_us(30);
}
/*
等待DS18B20的响应
返回1：未检测到DS18B20的存在
返回0：存在
*/
uint8_t DS18B20_Check(void)
{
uint8_t retry = 0;
DS18B20_IO_IN_SET();
while(HAL_GPIO_ReadPin(DS18B20_GPIO_Port, DS18B20_Pin) && (retry < 200))
{
retry++;
Delay_us(1);
}
if(retry >= 200)
return 1;
else
retry = 0;
while(!HAL_GPIO_ReadPin(DS18B20_GPIO_Port, DS18B20_Pin) && (retry < 240))
{
retry++;
Delay_us(1);
}
if(retry >= 240)
return 1;
return 0;
}
/*
从DS18B20读取一个位
返回值：1/0
*/
uint8_t DS18B20_Read_Bit(void)
{
uint8_t data = 0;
DS18B20_IO_OUT_SET();//推挽输出设置
HAL_GPIO_WritePin(DS18B20_GPIO_Port, DS18B20_Pin, GPIO_PIN_RESET); //DQ = 0
Delay_us(2);
HAL_GPIO_WritePin(DS18B20_GPIO_Port, DS18B20_Pin, GPIO_PIN_SET); //DQ
= 1
DS18B20_IO_IN_SET(); //输入上拉
Delay_us(12);
if(HAL_GPIO_ReadPin(DS18B20_GPIO_Port, DS18B20_Pin))
data = 1;
else
data = 0;
Delay_us(50);
return data;
}
/*
从DS18B20读取一个字节
返回值：读取到的数据
*/
uint8_t DS18B20_Read_Byte(void) //read one byte
{
uint8_t i,j,dat;
dat = 0;
for(i = 1;i <= 8;i++)
{
j = DS18B20_Read_Bit();
dat = (j << 7) | (dat >> 1);
}
return dat;
}
/*
写一个字节到DS18B20
dat：要写入的字节
*/
void DS18B20_Write_Byte(uint8_t dat)
{
uint8_t j;
uint8_t testb;
DS18B20_IO_OUT_SET();//推挽输出设置
for(j = 1;j <= 8;j++)
{
testb = dat & 0x01;
dat = dat >> 1;
if(testb)
{
HAL_GPIO_WritePin(DS18B20_GPIO_Port, DS18B20_Pin, GPIO_PIN_RESET);
//DQ = 0 write 1
Delay_us(2);
HAL_GPIO_WritePin(DS18B20_GPIO_Port, DS18B20_Pin, GPIO_PIN_SET);
//DQ = 1
Delay_us(60);
}
else
{
HAL_GPIO_WritePin(DS18B20_GPIO_Port, DS18B20_Pin, GPIO_PIN_RESET);
//DQ = 0 write 0
Delay_us(60);
HAL_GPIO_WritePin(DS18B20_GPIO_Port, DS18B20_Pin, GPIO_PIN_SET);
//DQ = 1
Delay_us(2);
}
}
}
/*
开始温度转换
*/
void DS18B20_Start(void) //ds18b20 start convert
{
DS18B20_Rst();
DS18B20_Check();
DS18B20_Write_Byte(0xcc);//skip rom
DS18B20_Write_Byte(0x44);//convert
}
/*
设置为9位精度
*/
void DS18B20_Comfig2(void) //
{
DS18B20_Rst();
DS18B20_Check();
DS18B20_Write_Byte(0xcc);//skip rom
DS18B20_Write_Byte(0x4e);//write
}
/*
初始化DS18B20的IO口DQ同时检测DS的存在
返回1：不存在
返回0：存在
*/
//uint8_t DS18B20_init(void)
//{
// ;
//}
/*
从DS18B20得到温度值
精度：0.5摄氏度
返回值：温度值
*/
uint16_t DS18B20_Get_Temp(void)
{
uint8_t temp;
uint8_t i = 0;
uint8_t TL,TH;
uint16_t tem;
#ifdef CONFIG_DS18B20
uint8_t FD,FH,RG;
#endif
#ifdef CONFIG_DS18B20
DS18B20_Comfig2();
DS18B20_Write_Byte(100);
DS18B20_Write_Byte(0);
DS18B20_Write_Byte(0x1f);
// DS18B20_Start();
#endif
DS18B20_Rst();
i = DS18B20_Check();
if(i == 1)
return 0xffee;
DS18B20_Write_Byte(0xcc);//skip rom
DS18B20_Write_Byte(0xbe);//read data
TL = DS18B20_Read_Byte();//LSB
TH = DS18B20_Read_Byte();//MSB
#ifdef CONFIG_DS18B20
FD = DS18B20_Read_Byte();
FH = DS18B20_Read_Byte();
RG = DS18B20_Read_Byte();
printf("RG = %X\r\n",RG);
#endif
if(TH > 7)
{
TH = ~TH;
TL = ~TL;
temp = 0; //温度为负
}
else
temp = 1; //温度为正
tem = TH; //获得高8位
tem <<= 8;
tem += TL;//获得低8位
tem = (float)(tem >> 3) * 0.5 *100;//转换
if(temp)
return tem; //返回温度值
else
return -tem;
}
《DS18B20.h》
#ifndef __DS18B20_H
#define __DS18B20_H
#define DS18B20_IO_OUT_SET() //{DS18B20_GPIO_Port->MODER &= 0xFFFFFFF3;GPIOF->MODER |= 1 << 2;GPIOF->PUPDR &= 0xFFFFFFF3;} //输出推挽 其余设置 默认
#define DS18B20_IO_IN_SET() //{DS18B20_GPIO_Port->MODER &= 0xFFFFFFF3;GPIOF->PUPDR &= 0xFFFFFFF3;GPIOF->PUPDR |= 1 << 2;} //设置输入上拉
//#define CONFIG_DS18B20 //设置DS18B20的 分辨率
/*
开始温度转换
*/
void DS18B20_Start(void); //ds18b20 start convert
/*
从DS18B20得到温度值
精度：0.5摄氏度
返回值：温度值
*/
uint16_t DS18B20_Get_Temp(void);
/*
微秒级延时用函数
*/
void Delay_us(uint16_t nus);
#endif
《gpio.c》
/**
******************************************************************************
* File Name : gpio.c
* Description : This file provides code for the configuration
* of all used GPIO pins.
******************************************************************************
*
* COPYRIGHT(c) 2016 STMicroelectronics
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. Neither the name of STMicroelectronics nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "gpio.h"
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/*----------------------------------------------------------------------------*/
/* Configure GPIO */
/*----------------------------------------------------------------------------*/
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/** Configure pins as
* Analog
* Input
* Output
* EVENT_OUT
* EXTI
*/
void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct;
/* GPIO Ports Clock Enable */
__GPIOF_CLK_ENABLE();
__GPIOA_CLK_ENABLE();
__GPIOB_CLK_ENABLE();
/*Configure GPIO pins : PAPin PAPin PAPin PAPin
PAPin */
GPIO_InitStruct.Pin = CD4053_Pin|C_S1_Pin|C_S2_Pin|C_S3_Pin
|C_S4_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_LOW;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/*Configure GPIO pin : PA7 */
GPIO_InitStruct.Pin = GPIO_PIN_7;
GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/*Configure GPIO pin : PtPin */
GPIO_InitStruct.Pin = DS18B20_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_LOW;
HAL_GPIO_Init(DS18B20_GPIO_Port, &GPIO_InitStruct);
/* EXTI interrupt init*/
HAL_NVIC_SetPriority(EXTI4_15_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(EXTI4_15_IRQn);
}
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
/**
* @}
*/
/**
* @}
*/
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
《tim.c》
/**
******************************************************************************
* File Name : TIM.c
* Description : This file provides code for the configuration
* of the TIM instances.
******************************************************************************
*
* COPYRIGHT(c) 2016 STMicroelectronics
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. Neither the name of STMicroelectronics nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "tim.h"
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
TIM_HandleTypeDef htim14;
TIM_HandleTypeDef htim16;
TIM_HandleTypeDef htim17;
/* TIM14 init function */
void MX_TIM14_Init(void)
{
htim14.Instance = TIM14;
htim14.Init.Prescaler = 0;
htim14.Init.CounterMode = TIM_COUNTERMODE_UP;
htim14.Init.Period = 65535;
htim14.Init.ClockDivision = TIM_CLOCKDIVISION_DIV2;
HAL_TIM_Base_Init(&htim14);
}
/* TIM16 init function */
void MX_TIM16_Init(void)
{
htim16.Instance = TIM16;
htim16.Init.Prescaler = TIM16_PSC;
htim16.Init.CounterMode = TIM_COUNTERMODE_UP;
htim16.Init.Period = 65535;
htim16.Init.ClockDivision = TIM_CLOCKDIVISION_DIV2;
htim16.Init.RepetitionCounter = 0;
HAL_TIM_Base_Init(&htim16);
}
/* TIM17 init function */
void MX_TIM17_Init(void)
{
htim17.Instance = TIM17;
htim17.Init.Prescaler = 0;
htim17.Init.CounterMode = TIM_COUNTERMODE_UP;
htim17.Init.Period = 65535;
htim17.Init.ClockDivision = TIM_CLOCKDIVISION_DIV2;
htim17.Init.RepetitionCounter = 0;
HAL_TIM_Base_Init(&htim17);
}
void HAL_TIM_Base_MspInit(TIM_HandleTypeDef* htim_base)
{
if(htim_base->Instance==TIM14)
{
/* USER CODE BEGIN TIM14_MspInit 0 */
/* USER CODE END TIM14_MspInit 0 */
/* Peripheral clock enable */
__TIM14_CLK_ENABLE();
/* USER CODE BEGIN TIM14_MspInit 1 */
/* USER CODE END TIM14_MspInit 1 */
}
else if(htim_base->Instance==TIM16)
{
/* USER CODE BEGIN TIM16_MspInit 0 */
/* USER CODE END TIM16_MspInit 0 */
/* Peripheral clock enable */
__TIM16_CLK_ENABLE();
/* USER CODE BEGIN TIM16_MspInit 1 */
/* USER CODE END TIM16_MspInit 1 */
}
else if(htim_base->Instance==TIM17)
{
/* USER CODE BEGIN TIM17_MspInit 0 */
/* USER CODE END TIM17_MspInit 0 */
/* Peripheral clock enable */
__TIM17_CLK_ENABLE();
/* USER CODE BEGIN TIM17_MspInit 1 */
/* USER CODE END TIM17_MspInit 1 */
}
}
void HAL_TIM_Base_MspDeInit(TIM_HandleTypeDef* htim_base)
{
if(htim_base->Instance==TIM14)
{
/* USER CODE BEGIN TIM14_MspDeInit 0 */
/* USER CODE END TIM14_MspDeInit 0 */
/* Peripheral clock disable */
__TIM14_CLK_DISABLE();
/* USER CODE BEGIN TIM14_MspDeInit 1 */
/* USER CODE END TIM14_MspDeInit 1 */
}
else if(htim_base->Instance==TIM16)
{
/* USER CODE BEGIN TIM16_MspDeInit 0 */
/* USER CODE END TIM16_MspDeInit 0 */
/* Peripheral clock disable */
__TIM16_CLK_DISABLE();
/* USER CODE BEGIN TIM16_MspDeInit 1 */
/* USER CODE END TIM16_MspDeInit 1 */
}
else if(htim_base->Instance==TIM17)
{
/* USER CODE BEGIN TIM17_MspDeInit 0 */
/* USER CODE END TIM17_MspDeInit 0 */
/* Peripheral clock disable */
__TIM17_CLK_DISABLE();
/* USER CODE BEGIN TIM17_MspDeInit 1 */
/* USER CODE END TIM17_MspDeInit 1 */
}
}
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/**
* @}
*/
/**
* @}
*/
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
本帖最后由 wambob 于 2016-5-4 17:44 编辑
18b20是单总线器件，外部需要上拉，而且时序对延时有要求，我开始跳这个，也没调成，最后还是用别人的例子移植成功了。这是我的18b20例程，希望对你有用
https://www.stmcu.org.cn/module/forum/thread-600041-1-1.html
首先确定传感器是不是好的
楼主给出你的连线图，免得大家怀疑上拉电阻什么的；
如有可能，用逻辑分析仪看波形更好。
楼主，关键就在初始化的480us，不同厂家的芯片这几百微秒都不尽相同，有的需要650us，有的要700us.你多试几次就OK了。
建议看一下看一下各端口的波形是否正确，是否是自己需要的延时，检查管脚功能是否设置是正确的，达到自己预定的效果