STM32的DHT12,I2C驱动，不行啊

只看该作者 · 2017-3-28 11:22

本帖最后由 hugo0chen 于 2017-3-28 12:13 编辑

完全没有数据，起始位 + 停止位

只看该作者 · 2017-3-28 11:23

本帖最后由 hugo0chen 于 2017-3-28 12:12 编辑

1、STM32L151的I2C2接口
PB10 -  SCL
PB11 -  SDA

2、DHT12的VCC是+3.3V

3、stm32的开发库版本是
  * @author  MCD Application Team
  * @version V1.1.1
  * @date 05-March-2012

4、DHT12的I2C时序

/**************************************************************************************************************************/
void Init_DHT12(void)
{
      GPIO_InitTypeDef GPIO_InitStructure;
      I2C_InitTypeDef I2C_InitStructure;

      RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2, ENABLE);
      RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
//       GPIO_PinAFConfig(GPIOB, GPIO_Pin_10, GPIO_AF_I2C2);
//       GPIO_PinAFConfig(GPIOB, GPIO_Pin_11, GPIO_AF_I2C2);这个有bug，改为寄存器直接操作
      GPIOB->AFR[1] |= 0x00000400;
      GPIOB->AFR[1] |= 0x00004000;

      GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
      GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
      GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_40MHz;
      GPIO_Init(GPIOB, &GPIO_InitStructure);

      GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
      GPIO_Init(GPIOB, &GPIO_InitStructure);

      I2C_InitStructure.I2C_ClockSpeed = 100000;
      I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
      I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
      I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
      I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
      I2C_InitStructure.I2C_OwnAddress1 = 0;
      I2C_Init(I2C2, &I2C_InitStructure);

      I2C_Cmd(I2C2, ENABLE);
      I2C_AcknowledgeConfig(I2C2, ENABLE);
}
/*************************************************************
*************************************************************/
#define MAX_I2C_WAIT_TIME  2000
uint8_t Convert_DHT12(float* Temprature, float* Humi)
{
      uint8_t Humi_H,Humi_L;
      uint8_t Temp_H;
      uint8_t Temp_L;
      uint8_t Temp_CAL;
      uint8_t temp;
      float getTemp, getHumi;
      uint32_t timeCount;

      // WRITE Operation----------------------
      timeCount = 0;
      while(I2C_GetFlagStatus(I2C2, I2C_FLAG_BUSY))
      {
            timeCount++;
            if(timeCount > MAX_I2C_WAIT_TIME)
            {
                     break;
            }
      }
      // Start
      I2C_GenerateSTART(I2C2, ENABLE);
      timeCount = 0;
      while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT))
      {
            timeCount++;
            if(timeCount > MAX_I2C_WAIT_TIME )
                     break;
      }
      //Dev SEL
      I2C_Send7bitAddress(I2C2, DHT12_ADDR, I2C_Direction_Transmitter);
      timeCount = 0;
      while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED))
      {
            timeCount++;
            if(timeCount > MAX_I2C_WAIT_TIME )
                     break;
      }
      I2C_SendData(I2C2, 0);
      timeCount = 0;
      while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED))
      {
            timeCount++;
            if(timeCount > MAX_I2C_WAIT_TIME )
                     break;
      }
      // READ-------
            timeCount = 0;
      while(I2C_GetFlagStatus(I2C2, I2C_FLAG_BUSY))
      {
            timeCount++;
            if(timeCount > MAX_I2C_WAIT_TIME)
            {
                     break;
            }
      }
            I2C_GenerateSTART(I2C2, ENABLE);    //Ö÷»ú·¢ËÍÆðÊ¼ÐÅºÅ
            timeCount = 0;
            while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT))
            {
                     timeCount++;
                     if(timeCount > MAX_I2C_WAIT_TIME )
                              break;
            }
            I2C_Send7bitAddress(I2C2, DHT12_ADDR, I2C_Direction_Receiver);
            timeCount = 0;
            while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED))
            {
                     timeCount++;
                     if(timeCount > MAX_I2C_WAIT_TIME )
                              break;
            }
            timeCount = 0;
      if(I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_RECEIVED))
            {
                     Humi_H = I2C_ReceiveData(I2C2);
                     //printf("Data Out Humi_H:%d  \n", Humi_H);
            }
            if(I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_RECEIVED))
            {
                     Humi_L = I2C_ReceiveData(I2C2);
                     //printf("Data Out Humi_L:%d  \n", Humi_L);
            }
            if(I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_RECEIVED))
            {
                     Temp_H = I2C_ReceiveData(I2C2);
                     //printf("Data Out Temp_H:%d  \n", Temp_H);
            }
            if(I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_RECEIVED))
            {
                     Temp_L = I2C_ReceiveData(I2C2);
                     //printf("Data Out Temp_L:%d  \n\r", Temp_L);
            }
            if(I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_RECEIVED))
            {
                     Temp_CAL = I2C_ReceiveData(I2C2);
                     //printf("Cal :%d \n\r", Temp_CAL);
            }
            I2C_AcknowledgeConfig(I2C2, DISABLE);
            I2C_GenerateSTOP(I2C2, ENABLE);
            I2C_AcknowledgeConfig(I2C2, ENABLE);
            printf("H: %x  .  %x  \n\rT:%x . %x \n\r" ,Humi_H, Humi_L, Temp_H, Temp_L);
            temp = (uint8_t)(Humi_H+Humi_L+Temp_H+Temp_L);
            printf("CAL: %x , %x \n\r", Temp_CAL, temp);
            if(Temp_CAL==temp)
            {
                     getHumi=Humi_H*10+Humi_L;

                     if(Temp_L&0X80)
                     {
                              getTemp =0-(Temp_H*10+((Temp_L&0x7F)));
                     }
                     else
                     {
                              getTemp=Temp_H*10+Temp_L;
                     }

                     if(getHumi>950)
                     {
                        getHumi=950;
                     }
                     else if(getHumi<200)
                     {
                              getHumi =200;
                     }

                     if(getTemp>600)
                     {
                        getTemp=600;
                     }
                     else if(getTemp<-200)
                     {
                              getTemp = -200;
                     }
                     *Temprature = getTemp/10.0;
                     *Humi = getHumi/10.0;
            }
            else
            {
                     printf("CRC Error !!\r\n");
            }

      return 0;
}示波器量测信号：

只看该作者 · 2017-3-28 12:52

参考别家的例子来写，IIC的不难，慢慢研究

只看该作者 · 2017-3-28 13:48

dawei360 发表于 2017-3-28 12:52
参考别家的例子来写，IIC的不难，慢慢研究

能提供个测试通过的例子吗？

只看该作者 · 2017-3-28 14:07

hugo0chen 发表于 2017-3-28 13:48
能提供个测试通过的例子吗？

还是不毁了你，慢慢想

只看该作者 · 2017-3-28 14:19

本帖最后由 hugo0chen 于 2017-3-28 14:21 编辑

dawei360 发表于 2017-3-28 14:07
还是不毁了你，慢慢想

(⊙o⊙)…·····参考别家的也是毁了我，

只看该作者 · 2017-3-28 21:09

hugo0chen 发表于 2017-3-28 14:19
(⊙o⊙)…·····参考别家的也是毁了我，

只看该作者 · 2017-3-28 23:31

单片机常用的总线如i2c、spi、uart等，将其硬件抽象层分离，相关外设在其抽象层上的应用函数接口调用。这样的好处是：
1、外设的驱动方便移植到任何单片机；
2、外设总线方便移植到其他单片机，只需更改部分寄存器配置；
3、总线调试OK后，调试新的外设程序时，不用重重复复调试总线的程序。
比如，楼上的程序分层就不够好，每次使用一个新的i2c外设，就相当于重新配置一次底层的总线，移植到其他单片机时又是重新写一遍，多吃力啊。

只看该作者 · 2017-3-29 10:22

Prry 发表于 2017-3-28 23:31
单片机常用的总线如i2c、spi、uart等，将其硬件抽象层分离，相关外设在其抽象层上的应用函数接口调用。这样 ...

受教了

只看该作者 · 2017-3-29 19:56

本帖最后由 hugo0chen 于 2017-3-29 20:00 编辑

#include "dht12.h"
#include "i2c.h"

#define I2C_CLOCK                300000
#define I2C_OWN_ADDR       0xC5                               //STM i2c address
/*************************************************************
*************************************************************/
static void init_I2C_InitStructure(void)
{
      I2C_InitTypeDef I2C_InitStructure;

      I2C_DeInit(I2C2);
      I2C_InitStructure.I2C_ClockSpeed = I2C_CLOCK;
      I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
      I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
      I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
      I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
      I2C_InitStructure.I2C_OwnAddress1 = I2C_OWN_ADDR;
      I2C_Init(I2C2, &I2C_InitStructure);

      I2C_Cmd(I2C2, ENABLE);
      I2C_AcknowledgeConfig(I2C2, ENABLE);
}

void inti_I2C2(void)
{
      GPIO_InitTypeDef GPIO_InitStructure;

      RCC_AHBPeriphClockCmd       (RCC_AHBPeriph_GPIOB, ENABLE);
      RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2, ENABLE);
//       GPIO_PinAFConfig(GPIOB, GPIO_Pin_10, GPIO_AF_I2C2);
//       GPIO_PinAFConfig(GPIOB, GPIO_Pin_11, GPIO_AF_I2C2);
      GPIOB->AFR[1] |= 0x00000400;
      GPIOB->AFR[1] |= 0x00004000;

      GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
      GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
      GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_40MHz;
      GPIO_Init(GPIOB, &GPIO_InitStructure);

      GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
      GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
      GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_40MHz;
      GPIO_Init(GPIOB, &GPIO_InitStructure);

      init_I2C_InitStructure();
}

uint32_t I2CTimeout;
#define WIAT_FOR_FLAG(flag, value, timeout, errorcode) I2CTimeout = timeout;\                                                                                     while(I2C_CheckEvent(I2C2,flag) != value )\
                                                                                    {       if((I2CTimeout--) == 0)\
                                                                                    return I2Cx_TIMEOUT_UserCallback(errorcode);}
/*************************************************************
*************************************************************/
static uint8_t I2Cx_TIMEOUT_UserCallback(uint8_t errorcode){
      I2C_GenerateSTOP(I2C2, ENABLE);
      I2C_SoftwareResetCmd(I2C2, ENABLE);
      I2C_SoftwareResetCmd(I2C2, DISABLE);
      init_I2C_InitStructure();
      return 1;
}

#define WAIT_FLAG_TIME 200
#define LONG_WAIT_**A_TIME (10*WAIT_FLAG_TIME)

static uint8_t Convert_DHT12(struct dht12_Reg_Data* reg_data)
{
      uint8_t id;
      uint8_t point[4];
      //------WRITE Operation-----
      WIAT_FOR_FLAG(I2C_FLAG_BUSY, RESET,LONG_WAIT_**A_TIME,1);

      // Start
      I2C_GenerateSTART(I2C2, ENABLE);

      //Test On EV5 and clear it
      WIAT_FOR_FLAG(I2C_EVENT_MASTER_MODE_SELECT, SET,WAIT_FLAG_TIME,2);

      //Dev SEL
      I2C_Send7bitAddress(I2C2, DHT12_ADDR, I2C_Direction_Transmitter);
      WIAT_FOR_FLAG(I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED, SET,LONG_WAIT_**A_TIME,3);

      //Send Byte Addr
      I2C_SendData(I2C2, REG_HUMIDITY_HIGH);
      WIAT_FOR_FLAG(I2C_EVENT_MASTER_BYTE_TRANSMITTED, SET,LONG_WAIT_**A_TIME,4);

      //-------READ Operation------
      I2C_GenerateSTART(I2C2, ENABLE);
      WIAT_FOR_FLAG(I2C_EVENT_MASTER_MODE_SELECT, SET,WAIT_FLAG_TIME,5);

      I2C_Send7bitAddress(I2C2, DHT12_ADDR, I2C_Direction_Receiver);
      // Read Data
      for( id = 0;id < 4;id++)
      {
            WIAT_FOR_FLAG(I2C_EVENT_MASTER_BYTE_RECEIVED, SET,LONG_WAIT_**A_TIME,6);
            point[id] = I2C_ReceiveData(I2C2);
      }
      I2C_AcknowledgeConfig(I2C2, DISABLE);
      WIAT_FOR_FLAG(I2C_EVENT_MASTER_BYTE_RECEIVED, SET,LONG_WAIT_**A_TIME,6);
      reg_data->cal_value = I2C_ReceiveData(I2C2);

      reg_data->humi_high             = point[0];
      reg_data->humi_low             = point[1];
      reg_data->temperature_high = point[2];
      reg_data->temperature_low  = point[3];

      I2C_GenerateSTOP(I2C2, ENABLE);
      I2C_AcknowledgeConfig(I2C2, ENABLE);
      return 0;
}

uint8_t getDHT12_Temp_Humi(float* temperature, float* huminity)
{
      uint8_t temp_cal = 0;
      float getTemp = 0.0, getHumi = 0.0;
      struct dht12_Reg_Data data;

      Convert_DHT12(&data);

      temp_cal = (uint8_t)(data.humi_high + data.humi_low + data.temperature_high + data.temperature_low);//Ö»È¡µÍ8Î»

      if(data.cal_value == temp_cal)
      {
            getHumi = data.humi_high*10 + data.humi_low;
            if(data.temperature_low&0X80)
            {
                     getTemp = 0 - (data.temperature_high*10 + ((data.temperature_low&0x7F)));
            }
            else
            {
                     getTemp=data.temperature_high*10+data.temperature_low;
            }
            if(getHumi > 950)
            {
                     getHumi = 950;
            }
            else if(getHumi < 200)
            {
                     getHumi = 200;
            }

            if(getTemp > 600)
            {
                     getTemp = 600;
            }
            else if(getTemp < -200)
            {
                     getTemp = -200;
            }
            *temperature = getTemp/10.0;
            *huminity = getHumi/10.0;
      }
      else
      {
            return 1;
      }
      return 0;
}

STM32的DHT12,I2C驱动，不行啊

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