hts221.c

00001 /**
00002  ******************************************************************************
00003  * @file    hts221.c
00004  * @author  MCD Application Team
00005  * @version V1.0.0
00006  * @date    14-February-2017
00007  * @brief   This file provides a set of functions needed to manage the HTS221
00008  *          humidity and temperature devices
00009  ******************************************************************************
00010  * @attention
00011  *
00012  * <h2><center>&copy; COPYRIGHT(c) 2017 STMicroelectronics</center></h2>
00013  *
00014  * Redistribution and use in source and binary forms, with or without modification,
00015  * are permitted provided that the following conditions are met:
00016  *   1. Redistributions of source code must retain the above copyright notice,
00017  *      this list of conditions and the following disclaimer.
00018  *   2. Redistributions in binary form must reproduce the above copyright notice,
00019  *      this list of conditions and the following disclaimer in the documentation
00020  *      and/or other materials provided with the distribution.
00021  *   3. Neither the name of STMicroelectronics nor the names of its contributors
00022  *      may be used to endorse or promote products derived from this software
00023  *      without specific prior written permission.
00024  *
00025  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
00026  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00027  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
00028  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
00029  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00030  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
00031  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
00032  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
00033  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
00034  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00035  *
00036  ******************************************************************************
00037  */
00038 
00039 /* Includes ------------------------------------------------------------------*/
00040 #include "hts221.h"
00041 
00042 /** @addtogroup BSP
00043   * @{
00044   */
00045 
00046 /** @addtogroup Component
00047   * @{
00048   */
00049 
00050 /** @defgroup HTS221 HTS221
00051   * @{
00052   */
00053 
00054 /** @defgroup HTS221_Private_Variables HTS221 Private Variables
00055   * @{
00056   */
00057 /* HTS221 Humidity Private Variables */
00058 HSENSOR_DrvTypeDef HTS221_H_Drv =
00059 {
00060   HTS221_H_Init,
00061   HTS221_H_ReadID,
00062   HTS221_H_ReadHumidity
00063 };
00064 
00065 /* HTS221_Temperature_Private_Variables */ 
00066 TSENSOR_DrvTypeDef HTS221_T_Drv =
00067 {
00068   HTS221_T_Init,
00069   0,
00070   0,
00071   HTS221_T_ReadTemp
00072 };
00073 /**
00074   * @}
00075   */ 
00076 
00077 /** @defgroup HTS221_Humidity_Private_Functions HTS221 Humidity Private Functions
00078   * @{
00079   */
00080 /**
00081   * @brief  Set HTS221 humidity sensor Initialization.
00082   */
00083 void HTS221_H_Init(uint16_t DeviceAddr)
00084 {
00085   uint8_t tmp;
00086   
00087   /* Read CTRL_REG1 */
00088   tmp = SENSOR_IO_Read(DeviceAddr, HTS221_CTRL_REG1);
00089   
00090   /* Enable BDU */
00091   tmp &= ~HTS221_BDU_MASK;
00092   tmp |= (1 << HTS221_BDU_BIT);
00093   
00094   /* Set default ODR */
00095   tmp &= ~HTS221_ODR_MASK;
00096   tmp |= (uint8_t)0x01; /* Set ODR to 1Hz */
00097   
00098   /* Activate the device */
00099   tmp |= HTS221_PD_MASK;
00100   
00101   /* Apply settings to CTRL_REG1 */
00102   SENSOR_IO_Write(DeviceAddr, HTS221_CTRL_REG1, tmp);
00103 }
00104 
00105 /**
00106   * @brief  Read HTS221 ID.
00107   * @retval ID 
00108   */
00109 uint8_t HTS221_H_ReadID(uint16_t DeviceAddr)
00110 {  
00111   uint8_t ctrl = 0x00;
00112  
00113   /* IO interface initialization */
00114   SENSOR_IO_Init(); 
00115   
00116   /* Read value at Who am I register address */
00117   ctrl = SENSOR_IO_Read(DeviceAddr, HTS221_WHO_AM_I_REG);
00118   
00119   return ctrl;
00120 }
00121 
00122 /**
00123   * @brief  Read humidity value of HTS221
00124   * @retval humidity value;
00125   */
00126 float HTS221_H_ReadHumidity(uint16_t DeviceAddr)
00127 {
00128   int16_t H0_T0_out, H1_T0_out, H_T_out;
00129   int16_t H0_rh, H1_rh;
00130   uint8_t buffer[2];
00131   float tmp_f;
00132 
00133   SENSOR_IO_ReadMultiple(DeviceAddr, (HTS221_H0_RH_X2 | 0x80), buffer, 2);
00134 
00135   H0_rh = buffer[0] >> 1;
00136   H1_rh = buffer[1] >> 1;
00137 
00138   SENSOR_IO_ReadMultiple(DeviceAddr, (HTS221_H0_T0_OUT_L | 0x80), buffer, 2);
00139 
00140   H0_T0_out = (((uint16_t)buffer[1]) << 8) | (uint16_t)buffer[0];
00141 
00142   SENSOR_IO_ReadMultiple(DeviceAddr, (HTS221_H1_T0_OUT_L | 0x80), buffer, 2);
00143 
00144   H1_T0_out = (((uint16_t)buffer[1]) << 8) | (uint16_t)buffer[0];
00145 
00146   SENSOR_IO_ReadMultiple(DeviceAddr, (HTS221_HR_OUT_L_REG | 0x80), buffer, 2);
00147 
00148   H_T_out = (((uint16_t)buffer[1]) << 8) | (uint16_t)buffer[0];
00149 
00150   tmp_f = (float)(H_T_out - H0_T0_out) * (float)(H1_rh - H0_rh) / (float)(H1_T0_out - H0_T0_out)  +  H0_rh;
00151   tmp_f *= 10.0f;
00152 
00153   tmp_f = ( tmp_f > 1000.0f ) ? 1000.0f
00154         : ( tmp_f <    0.0f ) ?    0.0f
00155         : tmp_f;
00156 
00157   return (tmp_f / 10.0f);
00158 }
00159 
00160 
00161 /**
00162   * @}
00163   */ 
00164 
00165 /** @defgroup HTS221_Temperature_Private_Functions HTS221 Temperature Private Functions
00166   * @{
00167   */
00168 
00169 /**
00170   * @brief  Set HTS221 temperature sensor Initialization.
00171   * @param  DeviceAddr: I2C device address
00172   * @param  InitStruct: pointer to a TSENSOR_InitTypeDef structure 
00173   *         that contains the configuration setting for the HTS221.
00174   */
00175 void HTS221_T_Init(uint16_t DeviceAddr, TSENSOR_InitTypeDef *pInitStruct)
00176 {  
00177   uint8_t tmp;
00178   
00179   /* Read CTRL_REG1 */
00180   tmp = SENSOR_IO_Read(DeviceAddr, HTS221_CTRL_REG1);
00181   
00182   /* Enable BDU */
00183   tmp &= ~HTS221_BDU_MASK;
00184   tmp |= (1 << HTS221_BDU_BIT);
00185   
00186   /* Set default ODR */
00187   tmp &= ~HTS221_ODR_MASK;
00188   tmp |= (uint8_t)0x01; /* Set ODR to 1Hz */
00189   
00190   /* Activate the device */
00191   tmp |= HTS221_PD_MASK;
00192   
00193   /* Apply settings to CTRL_REG1 */
00194   SENSOR_IO_Write(DeviceAddr, HTS221_CTRL_REG1, tmp);
00195 }
00196 
00197 /**
00198   * @brief  Read temperature value of HTS221
00199   * @param  DeviceAddr: I2C device address
00200   * @retval temperature value
00201   */
00202 float HTS221_T_ReadTemp(uint16_t DeviceAddr)
00203 {
00204   int16_t T0_out, T1_out, T_out, T0_degC_x8_u16, T1_degC_x8_u16;
00205   int16_t T0_degC, T1_degC;
00206   uint8_t buffer[4], tmp;
00207   float tmp_f;
00208 
00209   SENSOR_IO_ReadMultiple(DeviceAddr, (HTS221_T0_DEGC_X8 | 0x80), buffer, 2);
00210   tmp = SENSOR_IO_Read(DeviceAddr, HTS221_T0_T1_DEGC_H2);
00211 
00212   T0_degC_x8_u16 = (((uint16_t)(tmp & 0x03)) << 8) | ((uint16_t)buffer[0]);
00213   T1_degC_x8_u16 = (((uint16_t)(tmp & 0x0C)) << 6) | ((uint16_t)buffer[1]);
00214   T0_degC = T0_degC_x8_u16 >> 3;
00215   T1_degC = T1_degC_x8_u16 >> 3;
00216 
00217   SENSOR_IO_ReadMultiple(DeviceAddr, (HTS221_T0_OUT_L | 0x80), buffer, 4);
00218 
00219   T0_out = (((uint16_t)buffer[1]) << 8) | (uint16_t)buffer[0];
00220   T1_out = (((uint16_t)buffer[3]) << 8) | (uint16_t)buffer[2];
00221 
00222   SENSOR_IO_ReadMultiple(DeviceAddr, (HTS221_TEMP_OUT_L_REG | 0x80), buffer, 2);
00223 
00224   T_out = (((uint16_t)buffer[1]) << 8) | (uint16_t)buffer[0];
00225 
00226   tmp_f = (float)(T_out - T0_out) * (float)(T1_degC - T0_degC) / (float)(T1_out - T0_out)  +  T0_degC;
00227 
00228   return tmp_f;
00229 }
00230 
00231 /**
00232   * @}
00233   */
00234 
00235 /**
00236   * @}
00237   */
00238   
00239 /**
00240   * @}
00241   */
00242   
00243 /**
00244   * @}
00245   */
00246   
00247 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/