Manuel Caballero
I2C HUMIDITY AND TEMPERATURE SENSOR
Diff: SI7021.cpp
- Revision:
- 2:18c159179b08
- Parent:
- 0:3d466d4c2cd2
--- a/SI7021.cpp Mon Feb 05 12:31:34 2018 +0000
+++ b/SI7021.cpp Mon Feb 05 12:34:35 2018 +0000
@@ -0,0 +1,689 @@
+/**
+ * @brief SI7021.h
+ * @details I2C HUMIDITY AND TEMPERATURE SENSOR.
+ * Header file.
+ *
+ *
+ * @return NA
+ *
+ * @author Manuel Caballero
+ * @date 5/February/2018
+ * @version 5/February/2018 The ORIGIN
+ * @pre N/A.
+ * @warning N/A
+ * @pre This code belongs to AqueronteBlog ( http://unbarquero.blogspot.com ).
+ */
+
+#include "SI7021.h"
+
+
+SI7021::SI7021 ( PinName sda, PinName scl, uint32_t addr, uint32_t freq )
+ : _i2c ( sda, scl )
+ , _SI7021_Addr ( addr )
+{
+ _i2c.frequency( freq );
+}
+
+
+SI7021::~SI7021()
+{
+}
+
+
+
+/**
+ * @brief SI7021_Conf ( SI7021_measurement_resolution_t , SI7021_heater_t )
+ *
+ * @details It configures the device: resolution and heater.
+ *
+ * @param[in] myResolution: Resolution for RH and temperature.
+ * @param[in] myHeater: Enable/Disable heater.
+ *
+ * @param[out] N/A.
+ *
+ *
+ * @return Status of SI7021_Conf.
+ *
+ *
+ * @author Manuel Caballero
+ * @date 5/February/2018
+ * @version 5/February/2018 The ORIGIN
+ * @pre Except where noted, reserved register bits will always read back as “1,” and are not affected by write operations. For
+ * future compatibility, it is recommended that prior to a write operation, registers should be read. Then the values read
+ * from the RSVD bits should be written back unchanged during the write operation
+ * @warning N/A.
+ */
+SI7021::SI7021_status_t SI7021::SI7021_Conf ( SI7021_measurement_resolution_t myResolution, SI7021_heater_t myHeater )
+{
+ char cmd[] = { SI7021_READ_RH_T_USER_REGISTER_1, 0 };
+ uint32_t aux = 0;
+
+
+
+ // Read USER REGISTER to mask it
+ aux = _i2c.write ( _SI7021_Addr, &cmd[0], 1, true );
+ aux = _i2c.read ( _SI7021_Addr, &cmd[1], 1 );
+
+
+ // Update USER REGISTER according to user requirements
+ // Resolution
+ cmd[1] &= ~SI7021_RESOLUTION_MASK;
+ cmd[1] |= myResolution;
+
+ // Hater
+ cmd[1] &= ~SI7021_HTRE_MASK;
+ cmd[1] |= myHeater;
+
+
+
+ // Update USER REGISTER
+ cmd[0] = SI7021_WRITE_RH_T_USER_REGISTER_1;
+ aux = _i2c.write ( _SI7021_Addr, &cmd[0], 2, false );
+
+
+
+
+ if ( aux == I2C_SUCCESS )
+ return SI7021_SUCCESS;
+ else
+ return SI7021_FAILURE;
+}
+
+
+
+/**
+ * @brief SI7021_SoftReset ( void )
+ *
+ * @details It resets the device by software.
+ *
+ * @param[in] N/A
+ *
+ * @param[out] N/A.
+ *
+ *
+ * @return Status of SI7021_SoftReset.
+ *
+ *
+ * @author Manuel Caballero
+ * @date 5/February/2018
+ * @version 5/February/2018 The ORIGIN
+ * @pre N/A
+ * @warning The user MUST keep in mind that the device will be
+ * available after 5ms ( typically, 15ms maximum )
+ * The user MUST take care of this delay!.
+ */
+SI7021::SI7021_status_t SI7021::SI7021_SoftReset ( void )
+{
+ char cmd = SI7021_RESET;
+ uint32_t aux = 0;
+
+
+ aux = _i2c.write ( _SI7021_Addr, &cmd, 1, false );
+
+ // The user needs to wait for certain period of time before communicating
+ // with the device again.
+
+
+ if ( aux == I2C_SUCCESS )
+ return SI7021_SUCCESS;
+ else
+ return SI7021_FAILURE;
+}
+
+
+
+/**
+ * @brief SI7021_GetElectronicSerialNumber ( SI7021_vector_data_t* )
+ *
+ * @details It gets the electronic serial number.
+ *
+ * @param[in] N/A
+ *
+ * @param[out] mySerialNumber: The Electronic Serial Number.
+ *
+ *
+ * @return Status of SI7021_GetElectronicSerialNumber.
+ *
+ *
+ * @author Manuel Caballero
+ * @date 5/February/2018
+ * @version 5/February/2018 The ORIGIN
+ * @pre This function does NOT check the CRC
+ * @warning N/A.
+ */
+SI7021::SI7021_status_t SI7021::SI7021_GetElectronicSerialNumber ( SI7021_vector_data_t* mySerialNumber )
+{
+ char cmd[] = { SI7021_READ_ELECTRONIC_ID_FIRST_BYTE_CMD1, SI7021_READ_ELECTRONIC_ID_FIRST_BYTE_CMD2, 0, 0, 0, 0, 0, 0 };
+ uint32_t aux = 0;
+
+
+ // Read Electronic Serial Number. First Access
+ aux = _i2c.write ( _SI7021_Addr, &cmd[0], 2, true );
+ aux = _i2c.read ( _SI7021_Addr, &cmd[0], sizeof( cmd )/sizeof( cmd[0] ) );
+
+
+ mySerialNumber->ElectronicSerialNumber_MSB = ( ( cmd[0] << 24 ) | ( cmd[2] << 16 ) | ( cmd[4] << 8 ) | cmd[6] );
+
+
+ // Read Electronic Serial Number. Second Access
+ cmd[0] = SI7021_READ_ELECTRONIC_ID_SECOND_BYTE_CMD1;
+ cmd[1] = SI7021_READ_ELECTRONIC_ID_SECOND_BYTE_CMD2;
+
+ aux = _i2c.write ( _SI7021_Addr, &cmd[0], 2, true );
+ aux = _i2c.read ( _SI7021_Addr, &cmd[0], sizeof( cmd )/sizeof( cmd[0] ) );
+
+
+ mySerialNumber->ElectronicSerialNumber_LSB = ( ( cmd[0] << 24 ) | ( cmd[2] << 16 ) | ( cmd[4] << 8 ) | cmd[6] );
+
+
+
+
+ if ( aux == I2C_SUCCESS )
+ return SI7021_SUCCESS;
+ else
+ return SI7021_FAILURE;
+}
+
+
+
+/**
+ * @brief SI7021_GetFirmwareRevision ( SI7021_vector_data_t* )
+ *
+ * @details It gets the firmware revision.
+ *
+ * @param[in] N/A
+ *
+ * @param[out] myFirmwareRevision: The firmware revision.
+ *
+ *
+ * @return Status of SI7021_GetFirmwareRevision.
+ *
+ *
+ * @author Manuel Caballero
+ * @date 5/February/2018
+ * @version 5/February/2018 The ORIGIN
+ * @pre N/A.
+ * @warning N/A.
+ */
+SI7021::SI7021_status_t SI7021::SI7021_GetFirmwareRevision ( SI7021_vector_data_t* myFirmwareRevision )
+{
+ char cmd[] = { SI7021_READ_FIRMWARE_VERSION_CMD1, SI7021_READ_FIRMWARE_VERSION_CMD2 };
+ uint32_t aux = 0;
+
+
+ // Read the firmware revision
+ aux = _i2c.write ( _SI7021_Addr, &cmd[0], 2, true );
+ aux = _i2c.read ( _SI7021_Addr, &cmd[0], 1 );
+
+
+ myFirmwareRevision->FirmwareRevision = cmd[0];
+
+
+
+
+ if ( aux == I2C_SUCCESS )
+ return SI7021_SUCCESS;
+ else
+ return SI7021_FAILURE;
+}
+
+
+
+/**
+ * @brief SI7021_SetHeaterCurrent ( char )
+ *
+ * @details It sets the heater current.
+ *
+ * @param[in] myHeaterCurrent: New heater current value
+ *
+ * @param[out] N/A.
+ *
+ *
+ * @return Status of SI7021_SetHeaterCurrent.
+ *
+ *
+ * @author Manuel Caballero
+ * @date 5/February/2018
+ * @version 5/February/2018 The ORIGIN
+ * @pre N/A.
+ * @warning N/A.
+ */
+SI7021::SI7021_status_t SI7021::SI7021_SetHeaterCurrent ( char myHeaterCurrent )
+{
+ char cmd[] = { SI7021_READ_HEATER_CONTROL_REGISTER, 0 };
+ uint32_t aux = 0;
+
+
+ // myHeaterCurrent MUST be from 0 ( 0x00 ) to 15 ( 0x0F )
+ if ( myHeaterCurrent <= 15 ) {
+ // Read the heater control register
+ aux = _i2c.write ( _SI7021_Addr, &cmd[0], 1, true );
+ aux = _i2c.read ( _SI7021_Addr, &cmd[1], 1 );
+
+
+ // Mask the data
+ cmd[1] &= 0xF0;
+
+ // Update the value
+ cmd[0] = SI7021_WRITE_HEATER_CONTROL_REGISTER;
+ cmd[1] |= myHeaterCurrent;
+
+
+ aux = _i2c.write ( _SI7021_Addr, &cmd[0], 2, false );
+ } else
+ return SI7021_FAILURE;
+
+
+
+
+ if ( aux == I2C_SUCCESS )
+ return SI7021_SUCCESS;
+ else
+ return SI7021_FAILURE;
+}
+
+
+
+/**
+ * @brief SI7021_TriggerTemperature ( SI7021_master_mode_t )
+ *
+ * @details It performs a new temperature measurement.
+ *
+ * @param[in] myMode: HOLD/NO HOLD mode.
+ *
+ * @param[out] N/A
+ *
+ *
+ * @return Status of SI7021_TriggerTemperature.
+ *
+ *
+ * @author Manuel Caballero
+ * @date 5/February/2018
+ * @version 5/February/2018 The ORIGIN
+ * @pre N/A.
+ * @warning The user MUST respect the total conversion time.
+ * 14-bit temperature: 7ms ( 10.8ms max )
+ * 13-bit temperature: 4ms ( 6.2ms max )
+ * 12-bit temperature: 2.4ms ( 3.8ms max )
+ * 11-bit temperature: 1.5ms ( 2.4ms max )
+ */
+SI7021::SI7021_status_t SI7021::SI7021_TriggerTemperature ( SI7021_master_mode_t myMode )
+{
+ char cmd = 0;
+ bool myI2C_stop = false;
+ uint32_t aux = 0;
+
+
+
+ // Check the mode if it is HOLD MASTER MODE, then not generate a stop bit
+ if ( myMode == SI7021_HOLD_MASTER_MODE ) {
+ cmd = SI7021_MEASURE_TEMPERATURE_HOLD_MASTER_MODE;
+ myI2C_stop = true;
+ } else {
+ cmd = SI7021_MEASURE_TEMPERATURE_NO_HOLD_MASTER_MODE;
+ myI2C_stop = false;
+ }
+
+
+
+ aux = _i2c.write ( _SI7021_Addr, &cmd, 1, myI2C_stop );
+
+
+ // NOTE: The user has to respect the total conversion time!
+
+
+ if ( aux == I2C_SUCCESS )
+ return SI7021_SUCCESS;
+ else
+ return SI7021_FAILURE;
+}
+
+
+
+/**
+ * @brief SI7021_ReadTemperature ( SI7021_vector_data_t* )
+ *
+ * @details It reads the temperature.
+ *
+ * @param[in] myMode: HOLD/NO HOLD mode.
+ *
+ * @param[out] myTemperature: The current temperature
+ *
+ *
+ * @return Status of SI7021_ReadTemperature.
+ *
+ *
+ * @author Manuel Caballero
+ * @date 5/February/2018
+ * @version 5/February/2018 The ORIGIN
+ * @pre SI7021_TriggerTemperature MUST be called first. This function does NOT
+ * read CRC byte.
+ * @warning N/A.
+ */
+SI7021::SI7021_status_t SI7021::SI7021_ReadTemperature ( SI7021_vector_data_t* myTemperature )
+{
+ char cmd[] = { 0, 0 };
+ uint32_t aux = 0;
+
+
+
+
+ aux = _i2c.read ( _SI7021_Addr, &cmd[0], sizeof( cmd )/sizeof( cmd[0] ) );
+
+
+ // Check if the is a valid data
+ if ( ( cmd[1] & 0x02 ) == 0x00 ) {
+ // Parse the data
+ myTemperature->Temperature = ( ( cmd[0] << 8 ) | cmd[1] );
+ myTemperature->Temperature *= 175.72;
+ myTemperature->Temperature /= 65536.0;
+ myTemperature->Temperature -= 46.85;
+ } else
+ return SI7021_FAILURE;
+
+
+
+
+
+ if ( aux == I2C_SUCCESS )
+ return SI7021_SUCCESS;
+ else
+ return SI7021_FAILURE;
+}
+
+
+
+/**
+ * @brief SI7021_ReadRawTemperatureFromRH ( SI7021_vector_data_t* )
+ *
+ * @details It reads the raw temperature.
+ *
+ * @param[in] N/A.
+ *
+ * @param[out] myTemperature: The current temperature
+ *
+ *
+ * @return Status of SI7021_ReadRawTemperatureFromRH.
+ *
+ *
+ * @author Manuel Caballero
+ * @date 5/February/2018
+ * @version 5/February/2018 The ORIGIN
+ * @pre SI7021_TriggerHumidity MUST be called first.
+ * @warning N/A.
+ */
+SI7021::SI7021_status_t SI7021::SI7021_ReadRawTemperatureFromRH ( SI7021_vector_data_t* myTemperature )
+{
+ char cmd[] = { SI7021_READ_TEMPERATURE_VALUE_FROM_PREVIOUS_RH_MEASUREMENT, 0 };
+ uint32_t aux = 0;
+
+
+
+ aux = _i2c.write ( _SI7021_Addr, &cmd[0], 1, true );
+ aux = _i2c.read ( _SI7021_Addr, &cmd[0], 2 );
+
+
+ // Check if the is a valid data
+ if ( ( cmd[1] & 0x02 ) == 0x00 ) {
+ // Parse the data
+ myTemperature->Temperature = ( ( cmd[0] << 8 ) | cmd[1] );
+ } else
+ return SI7021_FAILURE;
+
+
+
+
+ if ( aux == I2C_SUCCESS )
+ return SI7021_SUCCESS;
+ else
+ return SI7021_FAILURE;
+}
+
+
+
+/**
+ * @brief SI7021_ReadTemperatureFromRH ( SI7021_vector_data_t* )
+ *
+ * @details It reads the temperature.
+ *
+ * @param[in] N/A.
+ *
+ * @param[out] myTemperature: The current temperature
+ *
+ *
+ * @return Status of SI7021_ReadTemperatureFromRH.
+ *
+ *
+ * @author Manuel Caballero
+ * @date 5/February/2018
+ * @version 5/February/2018 The ORIGIN
+ * @pre SI7021_TriggerHumidity MUST be called first.
+ * @warning N/A.
+ */
+SI7021::SI7021_status_t SI7021::SI7021_ReadTemperatureFromRH ( SI7021_vector_data_t* myTemperature )
+{
+ char cmd[] = { SI7021_READ_TEMPERATURE_VALUE_FROM_PREVIOUS_RH_MEASUREMENT, 0 };
+ uint32_t aux = 0;
+
+
+
+ aux = _i2c.write ( _SI7021_Addr, &cmd[0], 1, true );
+ aux = _i2c.read ( _SI7021_Addr, &cmd[0], 2 );
+
+
+ // Check if the is a valid data
+ if ( ( cmd[1] & 0x02 ) == 0x00 ) {
+ // Parse the data
+ myTemperature->Temperature = ( ( cmd[0] << 8 ) | cmd[1] );
+ myTemperature->Temperature *= 175.72;
+ myTemperature->Temperature /= 65536.0;
+ myTemperature->Temperature -= 46.85;
+ } else
+ return SI7021_FAILURE;
+
+
+
+
+ if ( aux == I2C_SUCCESS )
+ return SI7021_SUCCESS;
+ else
+ return SI7021_FAILURE;
+}
+
+
+
+/**
+ * @brief SI7021_TriggerHumidity ( SI7021_master_mode_t )
+ *
+ * @details It performs a new relative humidity measurement.
+ *
+ * @param[in] myMode: HOLD/NO HOLD MASTER mode.
+ *
+ * @param[out] N/A
+ *
+ *
+ * @return Status of SI7021_TriggerHumidity.
+ *
+ *
+ * @author Manuel Caballero
+ * @date 5/February/2018
+ * @version 5/February/2018 The ORIGIN
+ * @pre Initiating a RH measurement will also automatically initiate a temperature measurement.
+ * The total conversion time will be tCONV(RH) + tCONV(T).
+ * @warning The user MUST respect the total conversion time.
+ * 12-bit RH: 10ms ( 12ms max )
+ * 11-bit RH: 5.8ms ( 7ms max )
+ * 10-bit RH: 3.7ms ( 4.5ms max )
+ * 8-bit RH: 2.6ms ( 3.1ms max )
+ */
+SI7021::SI7021_status_t SI7021::SI7021_TriggerHumidity ( SI7021_master_mode_t myMode )
+{
+ char cmd = myMode;
+ uint32_t aux = 0;
+ bool myI2C_stop = false;
+
+
+
+ // Check the mode if it is HOLD MASTER MODE, then not generate a stop bit
+ if ( myMode == SI7021_HOLD_MASTER_MODE ) {
+ cmd = SI7021_MEASURE_RELATIVE_HUMIDITY_HOLD_MASTER_MODE;
+ myI2C_stop = true;
+ } else {
+ cmd = SI7021_MEASURE_RELATIVE_HUMIDITY_NO_HOLD_MASTER_MODE;
+ myI2C_stop = false;
+ }
+
+
+ aux = _i2c.write ( _SI7021_Addr, &cmd, 1, myI2C_stop );
+
+
+ // NOTE: The user has to respect the total conversion time!
+
+
+ if ( aux == I2C_SUCCESS )
+ return SI7021_SUCCESS;
+ else
+ return SI7021_FAILURE;
+}
+
+
+
+/**
+ * @brief SI7021_ReadHumidity ( SI7021_vector_data_t* )
+ *
+ * @details It reads the relative humidity.
+ *
+ * @param[in] N/A.
+ *
+ * @param[out] myHumidity: The current HUMIDITY
+ *
+ *
+ * @return Status of SI7021_ReadHumidity.
+ *
+ *
+ * @author Manuel Caballero
+ * @date 5/February/2018
+ * @version 5/February/2018 The ORIGIN
+ * @pre SI7021_TriggerHumidity MUST be called first. This function does NOT
+ * read CRC byte.
+ * @warning N/A.
+ */
+SI7021::SI7021_status_t SI7021::SI7021_ReadHumidity ( SI7021_vector_data_t* myHumidity )
+{
+ char cmd[] = { 0, 0 };
+ uint32_t aux = 0;
+
+
+
+ aux = _i2c.read ( _SI7021_Addr, &cmd[0], sizeof( cmd )/sizeof( cmd[0] ) );
+
+
+ // Check if the is a valid data
+ if ( ( cmd[1] & 0x03 ) == 0x02 ) {
+ // Parse the data
+ myHumidity->RelativeHumidity = ( ( cmd[0] << 8 ) | cmd[1] );
+ myHumidity->RelativeHumidity *= 125.0;
+ myHumidity->RelativeHumidity /= 65536.0;
+ myHumidity->RelativeHumidity -= 6.0;
+ } else
+ return SI7021_FAILURE;
+
+
+
+
+ if ( aux == I2C_SUCCESS )
+ return SI7021_SUCCESS;
+ else
+ return SI7021_FAILURE;
+}
+
+
+
+/**
+ * @brief SI7021_ReadRawHumidity ( SI7021_vector_data_t* )
+ *
+ * @details It reads the raw relative humidity.
+ *
+ * @param[in] N/A.
+ *
+ * @param[out] myHumidity: The current HUMIDITY
+ *
+ *
+ * @return Status of SI7021_ReadRawHumidity.
+ *
+ *
+ * @author Manuel Caballero
+ * @date 5/February/2018
+ * @version 5/February/2018 The ORIGIN
+ * @pre SI7021_TriggerHumidity MUST be called first. This function does NOT
+ * read CRC byte.
+ * @warning N/A.
+ */
+SI7021::SI7021_status_t SI7021::SI7021_ReadRawHumidity ( SI7021_vector_data_t* myHumidity )
+{
+ char cmd[] = { 0, 0 };
+ uint32_t aux = 0;
+
+
+
+ aux = _i2c.read ( _SI7021_Addr, &cmd[0], sizeof( cmd )/sizeof( cmd[0] ) );
+
+
+ // Check if the is a valid data
+ if ( ( cmd[1] & 0x03 ) == 0x02 ) {
+ // Parse the data
+ myHumidity->RelativeHumidity = ( ( cmd[0] << 8 ) | cmd[1] );
+ } else
+ return SI7021_FAILURE;
+
+
+
+
+ if ( aux == I2C_SUCCESS )
+ return SI7021_SUCCESS;
+ else
+ return SI7021_FAILURE;
+}
+
+
+
+/**
+ * @brief SI7021_GetBatteryStatus ( SI7021_vector_data_t* )
+ *
+ * @details It reads the raw relative humidity.
+ *
+ * @param[in] N/A.
+ *
+ * @param[out] myBatteryStatus: The current battery status
+ *
+ *
+ * @return Status of SI7021_GetBatteryStatus.
+ *
+ *
+ * @author Manuel Caballero
+ * @date 5/February/2018
+ * @version 5/February/2018 The ORIGIN
+ * @pre N/A.
+ * @warning N/A.
+ */
+SI7021::SI7021_status_t SI7021::SI7021_GetBatteryStatus ( SI7021_vector_data_t* myBatteryStatus )
+{
+ char cmd = SI7021_READ_RH_T_USER_REGISTER_1;
+ uint32_t aux = 0;
+
+
+ aux = _i2c.write ( _SI7021_Addr, &cmd, 1, true );
+ aux = _i2c.read ( _SI7021_Addr, &cmd, 1 );
+
+
+ myBatteryStatus->BatteryStatus = ( SI7021_vdds_status_t )( cmd & SI7021_VDDS_STATUS_MASK );
+
+
+
+
+
+ if ( aux == I2C_SUCCESS )
+ return SI7021_SUCCESS;
+ else
+ return SI7021_FAILURE;
+}