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[活动专区] 【AT-START-F423测评】10.使用硬件I2C读取DHTC12温湿度数据

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2012|0
 楼主| yuyy1989 发表于 2023-11-4 17:23 | 显示全部楼层 |阅读模式
AT32F423, 开发板, I2c, DHTC12
#申请原创# @21小跑堂  

之前用模拟I2C的方式读取了BMP280的数据，这次换用硬件I2C实现对DHTC12温湿度的读取
在AT32 Work Bench中开启I2C1
QQ截图20231104170022.png
默认使用PC0和PC1来通讯，参数设置参考DHTC12的手册

QQ截图20231104170137.png
AT32已经提供了一个封装好的I2C操作库

QQ截图20231104171242.png
不过还是想自己实现一下I2C通讯代码
复制
  1. #define AT32I2C_TIMEOUT 0xFFFF
    


  2. 

  3. void yuyy_hard_iic_reset_ctrl2_register(i2c_type *iicx)
    

  4. {
    

  5.   iicx->ctrl2_bit.saddr     = 0;
    

  6.   iicx->ctrl2_bit.readh10   = 0;
    

  7.   iicx->ctrl2_bit.cnt       = 0;
    

  8.   iicx->ctrl2_bit.rlden     = 0;
    

  9.   iicx->ctrl2_bit.dir       = 0;
    

  10. }
    


  11. 

  12. uint8_t yuyy_hard_iic_wait_flag(i2c_type *iicx,uint32_t flag,flag_status status)
    

  13. {
    

  14.     uint16_t timeout = AT32I2C_TIMEOUT;
    

  15.     while(i2c_flag_get(iicx, flag) != status)
    

  16.     {
    

  17.         timeout -= 1;
    

  18.         if(timeout == 0)
    

  19.             return 1;
    

  20.     }
    

  21.     return 0;
    

  22. }
    


  23. 

  24. uint8_t yuyy_hard_iic_master_sendstop(i2c_type *iicx)
    

  25. {
    

  26.     i2c_stop_generate(iicx);
    

  27.     if(yuyy_hard_iic_wait_flag(iicx,I2C_STOPF_FLAG,SET))
    

  28.         return 1;
    

  29.     i2c_flag_clear(iicx, I2C_STOPF_FLAG);
    

  30.     return 0;
    

  31. }
    


  32. 

  33. uint8_t yuyy_hard_iic_master_sendstart(i2c_type *iicx,uint8_t devaddr,i2c_start_mode_type startmode,i2c_reload_stop_mode_type stopmode,uint8_t datalen)
    

  34. {
    

  35.     uint16_t timeout = AT32I2C_TIMEOUT;
    

  36.     if(yuyy_hard_iic_wait_flag(iicx,I2C_BUSYF_FLAG,RESET))
    

  37.         return 1;
    

  38.     i2c_transmit_set(iicx, devaddr<<1, datalen, stopmode, startmode);
    

  39.     return 0;
    

  40. }
    


  41. 

  42. uint8_t yuyy_hard_iic_master_senddatas(i2c_type *iicx,uint8_t *datas,uint8_t datalen)
    

  43. {
    

  44.     uint8_t i=0;
    


  45. 

  46.     while(i<datalen)
    

  47.     {
    

  48.         if(yuyy_hard_iic_wait_flag(iicx,I2C_TDIS_FLAG,SET))
    

  49.         {
    

  50.             if(i2c_flag_get(iicx, I2C_ACKFAIL_FLAG) != RESET)
    

  51.             {
    

  52.                 i2c_flag_clear(iicx, I2C_ACKFAIL_FLAG);
    

  53.                 return 3;
    

  54.             }
    

  55.             yuyy_hard_iic_master_sendstop(iicx);
    

  56.             return 2;
    

  57.         }
    

  58.         if(i2c_flag_get(iicx, I2C_ACKFAIL_FLAG) != RESET)
    

  59.         {
    

  60.             i2c_flag_clear(iicx, I2C_ACKFAIL_FLAG);
    

  61.             return 3;
    

  62.         }
    

  63.         i2c_data_send(iicx, datas[i]);
    

  64.         i += 1;
    

  65.     }
    

  66.     return 0;
    

  67. }
    


  68. 

  69. uint8_t yuyy_hard_iic_master_readdatas(i2c_type *iicx,uint8_t *datas,uint8_t datalen)
    

  70. {
    

  71.     uint8_t i=0;
    

  72.     
    

  73.     while(i<datalen)
    

  74.     {
    

  75.         if(yuyy_hard_iic_wait_flag(iicx,I2C_RDBF_FLAG,SET))
    

  76.         {
    

  77.             if(i2c_flag_get(iicx, I2C_ACKFAIL_FLAG) != RESET)
    

  78.             {
    

  79.                 i2c_flag_clear(iicx, I2C_ACKFAIL_FLAG);
    

  80.                 return 3;
    

  81.             }
    

  82.             yuyy_hard_iic_master_sendstop(iicx);
    

  83.             return 2;
    

  84.         }
    

  85.         datas[i] = i2c_data_receive(iicx);
    

  86.         i += 1;
    

  87.     }
    

  88.     return 0;
    

  89. }
    


  90. 

  91. uint8_t yuyy_hard_iic_master_sendregdatas(i2c_type *iicx,uint8_t devaddr,uint16_t regaddr,uint8_t regaddrlen,uint8_t *datas,uint8_t datalen)
    

  92. {
    

  93.     uint8_t err = 0,regdata[2];
    

  94.     err = yuyy_hard_iic_master_sendstart(iicx,devaddr,I2C_GEN_START_WRITE,I2C_SOFT_STOP_MODE,regaddrlen+datalen);
    

  95.     if(err == 0 && regaddrlen > 0)
    

  96.     {
    

  97.         regdata[0] = (regaddr >> 8)&0xFF;
    

  98.         regdata[1] = regaddr&0xFF;
    

  99.         if(regaddrlen == 1)
    

  100.             regdata[0] = regaddr&0xFF;
    

  101.         err = yuyy_hard_iic_master_senddatas(iicx,regdata,regaddrlen);
    

  102.     }
    

  103.     if(err == 0)
    

  104.         err = yuyy_hard_iic_master_senddatas(iicx,datas,datalen);
    

  105.     if(err == 0 && yuyy_hard_iic_wait_flag(iicx,I2C_TDC_FLAG,SET))
    

  106.             err = 4;
    

  107.     if(err == 0)
    

  108.         err = yuyy_hard_iic_master_sendstop(iicx);
    

  109.     if(err != 0)
    

  110.         yuyy_hard_iic_reset_ctrl2_register(iicx);
    

  111.     return err;
    

  112. }
    

  113. uint8_t yuyy_hard_iic_master_readregdatas(i2c_type *iicx,uint8_t devaddr,uint16_t regaddr,uint8_t regaddrlen,uint8_t *datas,uint8_t datalen)
    

  114. {
    

  115.     uint8_t err = 0,regdata[2];
    

  116.     if(regaddrlen > 0)
    

  117.     {
    

  118.         regdata[0] = (regaddr >> 8)&0xFF;
    

  119.         regdata[1] = regaddr&0xFF;
    

  120.         if(regaddrlen == 1)
    

  121.             regdata[0] = regaddr&0xFF;
    

  122.         err = yuyy_hard_iic_master_sendstart(iicx,devaddr,I2C_GEN_START_WRITE,I2C_SOFT_STOP_MODE,regaddrlen);
    

  123.         if(err == 0)
    

  124.             err = yuyy_hard_iic_master_senddatas(iicx,regdata,regaddrlen);
    

  125.         if(err == 0 && yuyy_hard_iic_wait_flag(iicx,I2C_TDC_FLAG,SET))
    

  126.             err = 4;
    

  127.     }
    

  128.     if(err == 0)
    

  129.         i2c_transmit_set(iicx, devaddr<<1, datalen, I2C_SOFT_STOP_MODE, I2C_GEN_START_READ);
    

  130.     if(err == 0)
    

  131.         err = yuyy_hard_iic_master_readdatas(iicx,datas,datalen);
    

  132.     if(err == 0)
    

  133.         err = yuyy_hard_iic_master_sendstop(iicx);
    

  134.     if(err != 0)
    

  135.         yuyy_hard_iic_reset_ctrl2_register(iicx);
    

  136.     return err;
    

  137. }
DHTC12通讯代码
复制
  1. #define DHTC12_I2C_ADDR 0x44
    


  2. 

  3. static uint16_t HumA,HumB;
    


  4. 

  5. uint8_t yuyy_dhtc12_writecmd(YUYY_DHTC12_DEV_t *dhtc12_dev,uint16_t cmd)
    

  6. {
    

  7.         return dhtc12_dev->iic_senddatas_func(dhtc12_dev->iicx,DHTC12_I2C_ADDR,cmd,2,NULL,0);
    

  8. }
    


  9. 

  10. uint8_t yuyy_dhtc12_readdatas(YUYY_DHTC12_DEV_t *dhtc12_dev,uint8_t *rdatas,uint8_t rlen)
    

  11. {
    

  12.         return dhtc12_dev->iic_readdatas_func(dhtc12_dev->iicx,DHTC12_I2C_ADDR,0,0,rdatas,rlen);
    

  13. }
    


  14. 

  15. uint8_t yuyy_dhtc12_readcmd(YUYY_DHTC12_DEV_t *dhtc12_dev,uint16_t cmd,uint8_t *rdatas,uint8_t rlen)
    

  16. {
    

  17.         return dhtc12_dev->iic_readdatas_func(dhtc12_dev->iicx,DHTC12_I2C_ADDR,cmd,2,rdatas,rlen);
    

  18. }
    


  19. 

  20. //初始化,获取湿度运算系数
    

  21. void yuyy_dhtc12_init(YUYY_DHTC12_DEV_t *dhtc12_dev)
    

  22. {
    

  23.     uint8_t x;
    

  24.     if(!dhtc12_dev->delayms_func)
    

  25.         dhtc12_dev->delayms_func = yuyy_delay_ms;
    

  26.     //复位传感器
    

  27.     yuyy_dhtc12_writecmd(dhtc12_dev,0x30A2);
    

  28.     yuyy_dhtc12_readcmd(dhtc12_dev,0xD208,&x,1);
    

  29.     HumA = (x<<8)&0xFF00;
    

  30.     yuyy_dhtc12_readcmd(dhtc12_dev,0xD209,&x,1);
    

  31.     HumA |= x;
    

  32.     
    

  33.     yuyy_dhtc12_readcmd(dhtc12_dev,0xD20A,&x,1);
    

  34.     HumB = (x<<8)&0xFF00;
    

  35.     yuyy_dhtc12_readcmd(dhtc12_dev,0xD20B,&x,1);
    

  36.     HumB |= x;
    

  37.     //HumA=0x7168;  HumB=0x2D73;
    

  38.     //ReadDatSH[6]={0xF3, 0xA9, 0xC0, 0x41, 0xB4, 0x87}
    

  39.     //27.6 48.4%
    

  40. }
    


  41. 

  42. const uint16_t POLYNOMIAL = 0x131; //P(x)=x^8+x^5+x^4+1 = 100110001
    


  43. 

  44. uint8_t yuyy_dhtc12_checkcrc(uint8_t Data[], uint8_t nbrOfBytes) 
    

  45. {
    

  46.     uint8_t crc = 0xff; //0
    

  47.     uint8_t byteCtr,Bit;
    

  48.     //calculates 8-Bit checksum with given polynomial
    

  49.     for (byteCtr = 0; byteCtr < nbrOfBytes; ++byteCtr)
    

  50.     { 
    

  51.         crc ^= (Data[byteCtr]);
    

  52.         for (Bit = 8; Bit > 0; --Bit)
    

  53.         { 
    

  54.             if (crc & 0x80) 
    

  55.                 crc = (crc << 1) ^ POLYNOMIAL;
    

  56.             else 
    

  57.                 crc = (crc << 1);
    

  58.         }
    

  59.     }
    

  60.     if (crc != Data[nbrOfBytes])
    

  61.     {
    

  62.         Data[nbrOfBytes] = crc;
    

  63.         return 0x01;
    

  64.     }
    

  65.     else 
    

  66.         return 0;
    

  67. }
    


  68. 

  69. //单次触发温湿度测量
    

  70. uint8_t yuyy_dhtc12_readHT(YUYY_DHTC12_DEV_t *dhtc12_dev,float *tem,float *hum)
    

  71. {
    

  72.     uint8_t i=0,errRe,ReadDatSH[6],CalCRC[3],errorflag=0;
    

  73.     int16_t TemBuf;
    

  74.     uint16_t CapBuf;
    

  75.     errRe = yuyy_dhtc12_writecmd(dhtc12_dev,0x2C10);
    

  76.     if(errRe)
    

  77.         errRe = yuyy_dhtc12_writecmd(dhtc12_dev,0x2C10);
    

  78.     if(errRe)
    

  79.     {
    

  80.         return 0x10|errRe; //发送命令失败
    

  81.     }
    

  82.     
    

  83.     dhtc12_dev->delayms_func(100);
    

  84.     errRe = yuyy_dhtc12_readdatas(dhtc12_dev,ReadDatSH,6);
    


  85. 

  86.     if(errRe)
    

  87.     {
    

  88.         return 0x20|errRe; //接收数据失败
    

  89.     }
    

  90.     CalCRC[0] = ReadDatSH[0];
    

  91.     CalCRC[1] = ReadDatSH[1];
    

  92.     CalCRC[2] = ReadDatSH[2];
    

  93.     errorflag = yuyy_dhtc12_checkcrc(CalCRC,2);
    

  94.     if(errorflag==0)
    

  95.     {
    

  96.         TemBuf = (int16_t)(((ReadDatSH[0]<<8)&0xFF00)|ReadDatSH[1]);
    

  97.         *tem = 40+(float)TemBuf/256.0;
    

  98.     }
    

  99.     CalCRC[0] = ReadDatSH[3];
    

  100.     CalCRC[1] = ReadDatSH[4];
    

  101.     CalCRC[2] = ReadDatSH[5];
    

  102.     errorflag <<= 1;
    

  103.     errorflag |= yuyy_dhtc12_checkcrc(CalCRC,2);
    

  104.     if(errorflag==0)
    

  105.     {
    

  106.         CapBuf = (uint16_t)(((ReadDatSH[3]<<8)&0xFF00)|ReadDatSH[4]);
    

  107.         *hum = (float)(CapBuf-HumB)*60.0/(float)(HumA-HumB)+30;
    

  108.         //20℃为5个湿度点  即1℃为0.25个湿度点  0.1℃为0.025
    

  109.         *hum = *hum+ 0.25*(*tem-25);
    

  110.         if(*hum>100)
    

  111.             *hum = 99.9;
    

  112.         else if(*hum<0)
    

  113.             *hum = 0;
    

  114.     }
    

  115.     return errorflag;        
    

  116. }
初始化和读取温湿度并打印出来
复制
  1. YUYY_DHTC12_DEV_t dhtc12_dev;
    

  2. void dhtc12_init()
    

  3. {
    

  4.     dhtc12_dev.iicx = I2C1;
    

  5.     dhtc12_dev.iic_readdatas_func = (yuyy_iic_master_readdatas_func_t)yuyy_hard_iic_master_readregdatas;
    

  6.     dhtc12_dev.iic_senddatas_func = (yuyy_iic_master_senddatas_func_t)yuyy_hard_iic_master_sendregdatas;
    

  7.     yuyy_dhtc12_init(&dhtc12_dev);
    

  8. }
    


  9. 

  10. void dhtc12_readTH()
    

  11. {
    

  12.     float humi,temp;
    

  13.     uint8_t result = yuyy_dhtc12_readHT(&dhtc12_dev,&temp,&humi);
    

  14.     if(YUYY_DHT11_OK == result)
    

  15.     {
    

  16.         printf("DHTC12 读取温度:%.1f℃ 湿度:%.1f%%\r\n",temp,humi);
    

  17.     }
    

  18.     else
    

  19.     {
    

  20.         printf("DHTC12 读取温度错误：%d\r\n",result);
    

  21.     }
    

  22. }
运行效果
QQ截图20231104172154.png

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