/*!
* \file mpl3115.h
*
* \brief MPL3115 Temperature, pressure and altitude sensor driver implementation
*
* \copyright Revised BSD License, see section \ref LICENSE.
*
* \code
* ______ _
* / _____) _ | |
* ( (____ _____ ____ _| |_ _____ ____| |__
* \____ \| ___ | (_ _) ___ |/ ___) _ \
* _____) ) ____| | | || |_| ____( (___| | | |
* (______/|_____)_|_|_| \__)_____)\____)_| |_|
* (C)2013-2017 Semtech
*
* \endcode
*
* \author Miguel Luis ( Semtech )
*
* \author Gregory Cristian ( Semtech )
*/
#include <stdbool.h>
#include "utilities.h"
#include "delay.h"
#include "i2c.h"
#include "mpl3115.h"
extern I2c_t I2c;
/*!
* I2C device address
*/
static uint8_t I2cDeviceAddr = 0;
/*!
* Indicates if the MPL3115 is initialized or not
*/
static bool MPL3115Initialized = false;
/*!
* Defines the barometric reading types
*/
typedef enum
{
PRESSURE,
ALTITUDE,
}BarometerReadingType_t;
/*!
* \brief Writes a byte at specified address in the device
*
* \param [IN]: addr
* \param [IN]: data
* \retval status [SUCCESS, FAIL]
*/
uint8_t MPL3115Write( uint8_t addr, uint8_t data );
/*!
* \brief Writes a buffer at specified address in the device
*
* \param [IN]: addr
* \param [IN]: data
* \param [IN]: size
* \retval status [SUCCESS, FAIL]
*/
uint8_t MPL3115WriteBuffer( uint8_t addr, uint8_t *data, uint8_t size );
/*!
* \brief Reads a byte at specified address in the device
*
* \param [IN]: addr
* \param [OUT]: data
* \retval status [SUCCESS, FAIL]
*/
uint8_t MPL3115Read( uint8_t addr, uint8_t *data );
/*!
* \brief Reads a buffer at specified address in the device
*
* \param [IN]: addr
* \param [OUT]: data
* \param [IN]: size
* \retval status [SUCCESS, FAIL]
*/
uint8_t MPL3115ReadBuffer( uint8_t addr, uint8_t *data, uint8_t size );
/*!
* \brief Sets the I2C device slave address
*
* \param [IN]: addr
*/
void MPL3115SetDeviceAddr( uint8_t addr );
/*!
* \brief Gets the I2C device slave address
*
* \retval: addr Current device slave address
*/
uint8_t MPL3115GetDeviceAddr( void );
/*!
* \brief Sets the device in barometer Mode
*/
void MPL3115SetModeBarometer( void );
/*!
* \brief Sets the device in altimeter Mode
*/
void MPL3115SetModeAltimeter( void );
/*!
* \brief Sets the device in standby
*/
void MPL3115SetModeStandby( void );
/*!
* \brief Sets the device in active Mode
*/
void MPL3115SetModeActive( void );
/*!
* \brief Toggles the OST bit causing the sensor to immediately take another
* reading
*/
void MPL3115ToggleOneShot( void );
uint8_t MPL3115Init( void )
{
uint8_t regVal = 0;
MPL3115SetDeviceAddr( MPL3115A_I2C_ADDRESS );
if( MPL3115Initialized == false )
{
MPL3115Write( CTRL_REG1, RST );
DelayMs( 50 );
I2cResetBus( &I2c );
// Check MPL3115 ID
MPL3115Read( MPL3115_ID, ®Val );
if( regVal != 0xC4 )
{
return FAIL;
}
MPL3115Write( PT_DATA_CFG_REG, DREM | PDEFE | TDEFE ); // Enable data ready flags for pressure and temperature )
MPL3115Write( CTRL_REG1, ALT | OS_32 | SBYB ); // Set sensor to active state with oversampling ratio 128 (512 ms between samples)
MPL3115Initialized = true;
}
return SUCCESS;
}
uint8_t MPL3115Reset( void )
{
// Reset all registers to POR values
if( MPL3115Write( CTRL_REG1, RST ) == SUCCESS )
{
return SUCCESS;
}
return FAIL;
}
uint8_t MPL3115Write( uint8_t addr, uint8_t data )
{
return MPL3115WriteBuffer( addr, &data, 1 );
}
uint8_t MPL3115WriteBuffer( uint8_t addr, uint8_t *data, uint8_t size )
{
return I2cWriteMemBuffer( &I2c, I2cDeviceAddr << 1, addr, data, size );
}
uint8_t MPL3115Read( uint8_t addr, uint8_t *data )
{
return MPL3115ReadBuffer( addr, data, 1 );
}
uint8_t MPL3115ReadBuffer( uint8_t addr, uint8_t *data, uint8_t size )
{
return I2cReadMemBuffer( &I2c, I2cDeviceAddr << 1, addr, data, size );
}
void MPL3115SetDeviceAddr( uint8_t addr )
{
I2cDeviceAddr = addr;
}
uint8_t MPL3115GetDeviceAddr( void )
{
return I2cDeviceAddr;
}
static float MPL3115ReadBarometer( BarometerReadingType_t type )
{
uint8_t counter = 0;
uint8_t tempBuf[3];
uint8_t msb = 0, csb = 0, lsb = 0;
uint8_t status = 0;
if( MPL3115Initialized == false )
{
return 0;
}
if( type == ALTITUDE )
{
MPL3115SetModeAltimeter( );
}
else
{
MPL3115SetModeBarometer( );
}
MPL3115ToggleOneShot( );
while( ( status & PDR ) != PDR )
{
MPL3115Read( STATUS_REG, &status );
DelayMs( 10 );
counter++;
if( counter > 20 )
{
MPL3115Initialized = false;
MPL3115Init( );
if( type == ALTITUDE )
{
MPL3115SetModeAltimeter( );
}
else
{
MPL3115SetModeBarometer( );
}
MPL3115ToggleOneShot( );
counter = 0;
while( ( status & PDR ) != PDR )
{
MPL3115Read( STATUS_REG, &status );
DelayMs( 10 );
counter++;
if( counter > 20 )
{
// Error out after max of 512 ms for a read
return 0;
}
}
}
}
MPL3115ReadBuffer( OUT_P_MSB_REG, tempBuf, 3 ); //Read altitude data
msb = tempBuf[0];
csb = tempBuf[1];
lsb = tempBuf[2];
if( type == ALTITUDE )
{
float altitude = 0;
float decimal = ( ( float )( lsb >> 4 ) ) / 16.0;
altitude = ( float )( ( int16_t )( ( msb << 8 ) | csb ) ) + decimal;
return( altitude );
}
else
{
float pressure = ( float )( ( msb << 16 | csb << 8 | lsb ) >> 6 );
lsb &= 0x30; // Bits 5/4 represent the fractional component
lsb >>= 4; // Get it right aligned
float decimal = ( ( float )lsb ) / 4.0;
pressure = pressure + decimal;
return( pressure );
}
}
float MPL3115ReadAltitude( void )
{
return MPL3115ReadBarometer( ALTITUDE );
}
float MPL3115ReadPressure( void )
{
return MPL3115ReadBarometer( PRESSURE );
}
float MPL3115ReadTemperature( void )
{
uint8_t counter = 0;
uint8_t tempBuf[2];
uint8_t msb = 0, lsb = 0;
bool negSign = false;
uint8_t val = 0;
float temperature = 0;
uint8_t status = 0;
if( MPL3115Initialized == false )
{
return 0;
}
MPL3115ToggleOneShot( );
while( ( status & TDR ) != TDR )
{
MPL3115Read( STATUS_REG, &status );
DelayMs( 10 );
counter++;
if( counter > 20 )
{
MPL3115Initialized = false;
MPL3115Init( );
MPL3115ToggleOneShot( );
counter = 0;
while( ( status & TDR ) != TDR )
{
MPL3115Read( STATUS_REG, &status );
DelayMs( 10 );
counter++;
if( counter > 20 )
{
// Error out after max of 512 ms for a read
return 0;
}
}
}
}
MPL3115ReadBuffer( OUT_T_MSB_REG, tempBuf, 2 );
msb = tempBuf[0];
lsb = tempBuf[1];
if( msb > 0x7F )
{
val = ~( ( msb << 8 ) + lsb ) + 1; // 2�s complement
msb = val >> 8;
lsb = val & 0x00F0;
negSign = true;
}
if( negSign == true )
{
temperature = 0 - ( msb + ( float )( ( lsb >> 4 ) / 16.0 ) );
}
else
{
temperature = msb + ( float )( ( lsb >> 4 ) / 16.0 );
}
MPL3115ToggleOneShot( );
return( temperature );
}
void MPL3115ToggleOneShot( void )
{
uint8_t ctrlReg = 0;
MPL3115SetModeStandby( );
MPL3115Read( CTRL_REG1, &ctrlReg ); // Read current settings
ctrlReg &= ~OST; // Clear OST bit
MPL3115Write( CTRL_REG1, ctrlReg );
MPL3115Read( CTRL_REG1, &ctrlReg ); // Read current settings to be safe
ctrlReg |= OST; // Set OST bit
MPL3115Write( CTRL_REG1, ctrlReg );
MPL3115SetModeActive( );
}
void MPL3115SetModeBarometer( void )
{
uint8_t ctrlReg = 0;
MPL3115SetModeStandby( );
MPL3115Read( CTRL_REG1, &ctrlReg ); // Read current settings
ctrlReg &= ~ALT; // Set ALT bit to zero
MPL3115Write( CTRL_REG1, ctrlReg );
MPL3115SetModeActive( );
}
void MPL3115SetModeAltimeter( void )
{
uint8_t ctrlReg = 0;
MPL3115SetModeStandby( );
MPL3115Read( CTRL_REG1, &ctrlReg ); // Read current settings
ctrlReg |= ALT; // Set ALT bit to one
MPL3115Write( CTRL_REG1, ctrlReg );
MPL3115SetModeActive( );
}
void MPL3115SetModeStandby( void )
{
uint8_t ctrlReg = 0;
MPL3115Read( CTRL_REG1, &ctrlReg );
ctrlReg &= ~SBYB; // Clear SBYB bit for Standby mode
MPL3115Write( CTRL_REG1, ctrlReg );
}
void MPL3115SetModeActive( void )
{
uint8_t ctrlReg = 0;
MPL3115Read( CTRL_REG1, &ctrlReg );
ctrlReg |= SBYB; // Set SBYB bit for Active mode
MPL3115Write( CTRL_REG1, ctrlReg );
}