hts221.c

00001 /**
00002  ******************************************************************************
00003  * @file    hts221.c
00004  * @author  MCD Application Team
00005  * @brief   This file provides a set of functions needed to manage the HTS221
00006  *          humidity and temperature devices
00007  ******************************************************************************
00008  * @attention
00009  *
00010  * <h2><center>&copy; Copyright (c) 2017 STMicroelectronics.
00011  * All rights reserved.</center></h2>
00012  *
00013  * This software component is licensed by ST under BSD 3-Clause license,
00014  * the "License"; You may not use this file except in compliance with the
00015  * License. You may obtain a copy of the License at:
00016  *                        opensource.org/licenses/BSD-3-Clause
00017  *
00018  ******************************************************************************
00019  */
00020 
00021 /* Includes ------------------------------------------------------------------*/
00022 #include "hts221.h"
00023 
00024 /** @addtogroup BSP
00025   * @{
00026   */
00027 
00028 /** @addtogroup Component
00029   * @{
00030   */
00031 
00032 /** @defgroup HTS221 HTS221
00033   * @{
00034   */
00035 
00036 /** @defgroup HTS221_Private_Variables HTS221 Private Variables
00037   * @{
00038   */
00039 /* HTS221 Humidity Private Variables */
00040 HSENSOR_DrvTypeDef HTS221_H_Drv =
00041 {
00042   HTS221_H_Init,
00043   HTS221_H_ReadID,
00044   HTS221_H_ReadHumidity
00045 };
00046 
00047 /* HTS221_Temperature_Private_Variables */ 
00048 TSENSOR_DrvTypeDef HTS221_T_Drv =
00049 {
00050   HTS221_T_Init,
00051   0,
00052   0,
00053   HTS221_T_ReadTemp
00054 };
00055 /**
00056   * @}
00057   */ 
00058 
00059 /** @defgroup HTS221_Humidity_Private_Functions HTS221 Humidity Private Functions
00060   * @{
00061   */
00062 /**
00063   * @brief  Set HTS221 humidity sensor Initialization.
00064   */
00065 void HTS221_H_Init(uint16_t DeviceAddr)
00066 {
00067   uint8_t tmp;
00068   
00069   /* Read CTRL_REG1 */
00070   tmp = SENSOR_IO_Read(DeviceAddr, HTS221_CTRL_REG1);
00071   
00072   /* Enable BDU */
00073   tmp &= ~HTS221_BDU_MASK;
00074   tmp |= (1 << HTS221_BDU_BIT);
00075   
00076   /* Set default ODR */
00077   tmp &= ~HTS221_ODR_MASK;
00078   tmp |= (uint8_t)0x01; /* Set ODR to 1Hz */
00079   
00080   /* Activate the device */
00081   tmp |= HTS221_PD_MASK;
00082   
00083   /* Apply settings to CTRL_REG1 */
00084   SENSOR_IO_Write(DeviceAddr, HTS221_CTRL_REG1, tmp);
00085 }
00086 
00087 /**
00088   * @brief  Read HTS221 ID.
00089   * @retval ID 
00090   */
00091 uint8_t HTS221_H_ReadID(uint16_t DeviceAddr)
00092 {  
00093   uint8_t ctrl = 0x00;
00094  
00095   /* IO interface initialization */
00096   SENSOR_IO_Init(); 
00097   
00098   /* Read value at Who am I register address */
00099   ctrl = SENSOR_IO_Read(DeviceAddr, HTS221_WHO_AM_I_REG);
00100   
00101   return ctrl;
00102 }
00103 
00104 /**
00105   * @brief  Read humidity value of HTS221
00106   * @retval humidity value;
00107   */
00108 float HTS221_H_ReadHumidity(uint16_t DeviceAddr)
00109 {
00110   int16_t H0_T0_out, H1_T0_out, H_T_out;
00111   int16_t H0_rh, H1_rh;
00112   uint8_t buffer[2];
00113   float tmp_f;
00114 
00115   SENSOR_IO_ReadMultiple(DeviceAddr, (HTS221_H0_RH_X2 | 0x80), buffer, 2);
00116 
00117   H0_rh = buffer[0] >> 1;
00118   H1_rh = buffer[1] >> 1;
00119 
00120   SENSOR_IO_ReadMultiple(DeviceAddr, (HTS221_H0_T0_OUT_L | 0x80), buffer, 2);
00121 
00122   H0_T0_out = (((uint16_t)buffer[1]) << 8) | (uint16_t)buffer[0];
00123 
00124   SENSOR_IO_ReadMultiple(DeviceAddr, (HTS221_H1_T0_OUT_L | 0x80), buffer, 2);
00125 
00126   H1_T0_out = (((uint16_t)buffer[1]) << 8) | (uint16_t)buffer[0];
00127 
00128   SENSOR_IO_ReadMultiple(DeviceAddr, (HTS221_HR_OUT_L_REG | 0x80), buffer, 2);
00129 
00130   H_T_out = (((uint16_t)buffer[1]) << 8) | (uint16_t)buffer[0];
00131 
00132   tmp_f = (float)(H_T_out - H0_T0_out) * (float)(H1_rh - H0_rh) / (float)(H1_T0_out - H0_T0_out)  +  H0_rh;
00133   tmp_f *= 10.0f;
00134 
00135   tmp_f = ( tmp_f > 1000.0f ) ? 1000.0f
00136         : ( tmp_f <    0.0f ) ?    0.0f
00137         : tmp_f;
00138 
00139   return (tmp_f / 10.0f);
00140 }
00141 
00142 
00143 /**
00144   * @}
00145   */ 
00146 
00147 /** @defgroup HTS221_Temperature_Private_Functions HTS221 Temperature Private Functions
00148   * @{
00149   */
00150 
00151 /**
00152   * @brief  Set HTS221 temperature sensor Initialization.
00153   * @param  DeviceAddr: I2C device address
00154   * @param  InitStruct: pointer to a TSENSOR_InitTypeDef structure 
00155   *         that contains the configuration setting for the HTS221.
00156   */
00157 void HTS221_T_Init(uint16_t DeviceAddr, TSENSOR_InitTypeDef *pInitStruct)
00158 {  
00159   uint8_t tmp;
00160   
00161   /* Read CTRL_REG1 */
00162   tmp = SENSOR_IO_Read(DeviceAddr, HTS221_CTRL_REG1);
00163   
00164   /* Enable BDU */
00165   tmp &= ~HTS221_BDU_MASK;
00166   tmp |= (1 << HTS221_BDU_BIT);
00167   
00168   /* Set default ODR */
00169   tmp &= ~HTS221_ODR_MASK;
00170   tmp |= (uint8_t)0x01; /* Set ODR to 1Hz */
00171   
00172   /* Activate the device */
00173   tmp |= HTS221_PD_MASK;
00174   
00175   /* Apply settings to CTRL_REG1 */
00176   SENSOR_IO_Write(DeviceAddr, HTS221_CTRL_REG1, tmp);
00177 }
00178 
00179 /**
00180   * @brief  Read temperature value of HTS221
00181   * @param  DeviceAddr: I2C device address
00182   * @retval temperature value
00183   */
00184 float HTS221_T_ReadTemp(uint16_t DeviceAddr)
00185 {
00186   int16_t T0_out, T1_out, T_out, T0_degC_x8_u16, T1_degC_x8_u16;
00187   int16_t T0_degC, T1_degC;
00188   uint8_t buffer[4], tmp;
00189   float tmp_f;
00190 
00191   SENSOR_IO_ReadMultiple(DeviceAddr, (HTS221_T0_DEGC_X8 | 0x80), buffer, 2);
00192   tmp = SENSOR_IO_Read(DeviceAddr, HTS221_T0_T1_DEGC_H2);
00193 
00194   T0_degC_x8_u16 = (((uint16_t)(tmp & 0x03)) << 8) | ((uint16_t)buffer[0]);
00195   T1_degC_x8_u16 = (((uint16_t)(tmp & 0x0C)) << 6) | ((uint16_t)buffer[1]);
00196   T0_degC = T0_degC_x8_u16 >> 3;
00197   T1_degC = T1_degC_x8_u16 >> 3;
00198 
00199   SENSOR_IO_ReadMultiple(DeviceAddr, (HTS221_T0_OUT_L | 0x80), buffer, 4);
00200 
00201   T0_out = (((uint16_t)buffer[1]) << 8) | (uint16_t)buffer[0];
00202   T1_out = (((uint16_t)buffer[3]) << 8) | (uint16_t)buffer[2];
00203 
00204   SENSOR_IO_ReadMultiple(DeviceAddr, (HTS221_TEMP_OUT_L_REG | 0x80), buffer, 2);
00205 
00206   T_out = (((uint16_t)buffer[1]) << 8) | (uint16_t)buffer[0];
00207 
00208   tmp_f = (float)(T_out - T0_out) * (float)(T1_degC - T0_degC) / (float)(T1_out - T0_out)  +  T0_degC;
00209 
00210   return tmp_f;
00211 }
00212 
00213 /**
00214   * @}
00215   */
00216 
00217 /**
00218   * @}
00219   */
00220   
00221 /**
00222   * @}
00223   */
00224   
00225 /**
00226   * @}
00227   */
00228   
00229 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/