Llibrary for the WiGo MPL3115A2, I2C Precision Altimeter sensor.

Dependents:   KL25Z_Batt_Test WIGO_MPL3115A2 Multi-Sensor SPACEmk2 ... more

30/05/2013 Added and tested the data acquisition using Interrupt. Added code for Altimeter trigger Interrupt but not yet tested.

Very basic library. Under development. Need to add in order: 1. IRQ configuration. 2. FIFO mode configuration.

MPL3115A2.cpp

Committer:
clemente
Date:
2013-08-22
Revision:
6:03c24251e500
Parent:
5:9edec5ee8bf4
Child:
7:59e9ba115d0a

File content as of revision 6:03c24251e500:

#include "MPL3115A2.h"

#define REG_WHO_AM_I        0x0C        // return 0xC4 by default
#define REG_STATUS          0x00
#define REG_CTRL_REG_1      0x26
#define REG_CTRL_REG_3      0x28
#define REG_CTRL_REG_4      0x29
#define REG_CTRL_REG_5      0x2A
#define REG_PRESSURE_MSB    0x01        // 3 byte pressure data
#define REG_ALTIMETER_MSB   0x01        // 3 byte altimeter data
#define REG_TEMP_MSB        0x04        // 2 byte temperature data
#define REG_PT_DATA_CFG     0x13
#define REG_P_TGT_MSB       0x16
#define REG_P_WND_MSB       0x19

#define UINT14_MAX        16383

// Status flag for data ready.
#define PTDR_STATUS       0x03        // Pressure Altitude and Temperature ready
#define PDR_STATUS        0x02        // Pressure and Altitude data ready
#define TDR_STATUS        0x01        // Temperature data ready

/** Interrupt schema
*
* :: The Altitude Trigger use the IRQ1.
* 
*   Altitude Trigger -- MPL3115A2_Int1.fall --- AltitudeTrg_IRQ --- user1_fptr
*
*
* :: The Data ready use the IRQ2. 
*
*   Data Ready -- MPL3115A2_Int2.fall --- DataReady_IRQ --- user2_fptr
*
*/
void (*user2_fptr)(void);               // Pointers to user function called after
void (*user1_fptr)(void);               // IRQ assertion.

//
InterruptIn MPL3115A2_Int1( PTD4);       // INT1
InterruptIn MPL3115A2_Int2( PTA12);      // INT2

MPL3115A2::MPL3115A2(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
    MPL3115A2_mode = BAROMETRIC_MODE;
    MPL3115A2_oversampling = OVERSAMPLE_RATIO_1;
    //
    user1_fptr = NULL;
    user2_fptr = NULL;
    MPL3115A2_Int1.fall( NULL);
    MPL3115A2_Int2.fall( NULL);
}

void MPL3115A2::Reset( void)
{
    unsigned char t;
    
    // soft reset...
    readRegs( REG_CTRL_REG_1, &t, 1);
    unsigned char data[2] = { REG_CTRL_REG_1, t|0x04};
    writeRegs(data, 2);    
    wait( 0.1);

}

void MPL3115A2::DataReady( void(*fptr)(void), unsigned char OS)
{
    unsigned char dt[5];
    unsigned char data[2];
    
    // Soft Reset
    Reset();
    
    Standby();
    
    // Clear all interrupts by reading the output registers.
    readRegs( REG_ALTIMETER_MSB, &dt[0], 5);
    getStatus();
    // Configure INT active low and pullup
    data[0] = REG_CTRL_REG_3;
    data[1] = 0x00;
    writeRegs(data, 2);    
    // Enable Interrupt fot data ready
    data[0] = REG_CTRL_REG_4;
    data[1] = 0x80;
    writeRegs(data, 2);    
    // Configure Interrupt to route to INT2
    data[0] = REG_CTRL_REG_5;
    data[1] = 0x00;
    writeRegs(data, 2);    
    data[0] = REG_PT_DATA_CFG;
    data[1] = 0x07;
    writeRegs(data, 2);    

    // Configure the OverSampling rate, Altimeter/Barometer mode and set the sensor Active
    data[0] = REG_CTRL_REG_1;
    data[1] = (OS<<3);
    //
    if (MPL3115A2_mode == BAROMETRIC_MODE)
        data[1] &= 0x7F;
    else
        data[1] |= 0x80;
    //
    data[1] |= 0x01; 
    writeRegs(data, 2);    

    user2_fptr = fptr;
    MPL3115A2_Int2.fall( this, &MPL3115A2::DataReady_IRQ);

}

void MPL3115A2::DataReady_IRQ( void)
{
    // Clear the IRQ flag
    getStatus();
    // Run the user supplied function
    user2_fptr();   
}

void MPL3115A2::AltitudeTrigger( void(*fptr)(void), unsigned short level)
{
    unsigned char dt[5];
    unsigned char data[2];

    // Soft Reset
    Reset();
    
    // The device is on standby
    Standby();
    
    // Clear all interrupts by reading the output registers.
    readRegs( REG_ALTIMETER_MSB, &dt[0], 5);
    getStatus();

    // Write Target and Window Values
    dt[0] = REG_P_TGT_MSB;
    dt[1] = (level>>8);
    dt[2] = (level&0xFF);
    writeRegs( dt, 3);
    
    // Window values are zero
    dt[0] = REG_P_WND_MSB;
    dt[1] = 0;
    dt[2] = 0;
    writeRegs( dt, 3);

    // Enable Pressure Threshold interrupt
    data[0] = REG_CTRL_REG_4;
    data[1] = 0x08;
    writeRegs( data, 2);
    // Interrupt is routed to INT1
    data[0] = REG_CTRL_REG_5;
    data[1] = 0x08;
    writeRegs( data, 2);
    data[0] = REG_PT_DATA_CFG;
    data[1] = 0x07;
    writeRegs(data, 2);    
    // Configure the OverSampling rate, Altimeter mode and set the sensor Active
    data[0] = REG_CTRL_REG_1;
    data[1] = 0x81 | (MPL3115A2_oversampling<<3);    
    writeRegs(data, 2);    

    user1_fptr = fptr;
    MPL3115A2_Int1.fall( this, &MPL3115A2::AltitudeTrg_IRQ);

}

void MPL3115A2::AltitudeTrg_IRQ( void)
{
    // Clear the IRQ flag
    getStatus();
    // Run the user supplied function
    user1_fptr();   

}

void MPL3115A2::Barometric_Mode( void)
{
    unsigned char t;
    unsigned char data[2];
    
    Standby();

    // soft reset...
    Reset();
        
    Standby();
    readRegs( REG_CTRL_REG_1, &t, 1);
    
    // Set the Barometric mode
    data[0] = REG_CTRL_REG_1;
    data[1] = t&0x7F;
    writeRegs(data, 2);    

    data[0] = REG_PT_DATA_CFG;
    data[1] = 0x07;
    writeRegs(data, 2);    

    Oversample_Ratio( MPL3115A2_oversampling);
    
    Active();
    
    MPL3115A2_mode = BAROMETRIC_MODE;
}

void MPL3115A2::Altimeter_Mode( void)
{
    unsigned char t;
    unsigned char data[2];
    
    Standby();

    // soft reset...
    Reset();    
    
    Standby();
    readRegs( REG_CTRL_REG_1, &t, 1);

    data[0] = REG_CTRL_REG_1;
    data[1] = t|0x80;
    writeRegs(data, 2);    

    data[0] = REG_PT_DATA_CFG;
    data[1] = 0x07;
    writeRegs(data, 2);    

    Oversample_Ratio( MPL3115A2_oversampling);
    
    Active();
    
    MPL3115A2_mode = ALTIMETER_MODE;
}

void MPL3115A2::Oversample_Ratio( unsigned int ratio)
{
    unsigned char t;
    
    Standby();
    readRegs( REG_CTRL_REG_1, &t, 1);

    t = t & 0xE7;
    t = t | ( ratio<<3);

    unsigned char data[2] = { REG_CTRL_REG_1, t};
    writeRegs(data, 2);    

    Active();
    
    MPL3115A2_oversampling = ratio;
}


void MPL3115A2::Active( void)
{
    unsigned char t;
    
    // Activate the peripheral
    readRegs(REG_CTRL_REG_1, &t, 1);
    unsigned char data[2] = {REG_CTRL_REG_1, t|0x01};
    writeRegs(data, 2);
}

void MPL3115A2::Standby( void)
{
    unsigned char t;
    
    // Standby
    readRegs(REG_CTRL_REG_1, &t, 1);
    unsigned char data[2] = {REG_CTRL_REG_1, t&0xFE};
    writeRegs(data, 2);
}

unsigned char MPL3115A2::getDeviceID() {
    unsigned char device_id = 0;
    readRegs(REG_WHO_AM_I, &device_id, 1);
    return device_id;
}

unsigned int MPL3115A2::isDataAvailable( void)
{
    unsigned char status;
    
    readRegs( REG_STATUS, &status, 1);

    return ((status>>1));
    
}

unsigned char MPL3115A2::getStatus( void)
{
    unsigned char status;
    
    readRegs( REG_STATUS, &status, 1);
    return status;
}

unsigned int MPL3115A2::getAllData( float *f)
{
    if ( isDataAvailable() & PTDR_STATUS) {
        if ( MPL3115A2_mode == ALTIMETER_MODE) {
            f[0] = getAltimeter();
        } else {
            f[0] = getPressure();
        }
        
        f[1] = getTemperature();
        //
        return 1;
    } else
        return 0;
}

float MPL3115A2::getAltimeter( void)
{
    unsigned char dt[3];
    unsigned short altm;
    float faltm;
    
    /*
    * dt[0] = Bits 12-19 of 20-bit real-time Altitude sample. (b7-b0)
    * dt[1] = Bits 4-11 of 20-bit real-time Altitude sample. (b7-b0)
    * dt[2] = Bits 0-3 of 20-bit real-time Altitude sample (b7-b4)
    */
    readRegs( REG_ALTIMETER_MSB, &dt[0], 3);
    altm = (dt[0]<<8) | dt[1];
    //
    if ( dt[0] > 0x7F) {
        altm = ~altm + 1;
        faltm = (float)altm * -1.0f;
    } else {
        faltm = (float)altm * 1.0f;
    }
    //
    faltm = faltm+((float)(dt[2]>>4) * 0.0625f);
    return faltm;
}

float MPL3115A2::getPressure( void)
{
    unsigned char dt[3];
    unsigned int prs;
    float fprs;
    
    /*
    * dt[0] = Bits 12-19 of 20-bit real-time Pressure sample. (b7-b0)
    * dt[1] = Bits 4-11 of 20-bit real-time Pressure sample. (b7-b0)
    * dt[2] = Bits 0-3 of 20-bit real-time Pressure sample (b7-b4)
    */
    readRegs( REG_PRESSURE_MSB, &dt[0], 3);
    prs = (dt[0]<<10) | (dt[1]<<2) | (dt[2]>>6);
    //
    fprs = (float)prs * 1.0f;
    
    if ( dt[2] & 0x20)
        fprs += 0.25f;
    if ( dt[2] & 0x10)
        fprs += 0.5f;
    
    return fprs;
}


float MPL3115A2::getTemperature( void)
{
    unsigned char dt[2];
    unsigned short temp;
    float ftemp;
    
    /*
    * dt[0] = Bits 4-11 of 16-bit real-time temperature sample. (b7-b0)
    * dt[1] = Bits 0-3 of 16-bit real-time temperature sample. (b7-b4)
    */
    readRegs( REG_TEMP_MSB, &dt[0], 2);
    temp = dt[0];
    //
    if ( dt[0] > 0x7F) {
        temp = ~temp + 1;
        ftemp = (float)temp * -1.0f;
    } else {
        ftemp = (float)temp * 1.0f;
    }
    //
    ftemp = ftemp+((float)(dt[1]>>4) * 0.0625f);
    return ftemp;

}

unsigned int MPL3115A2::getAllDataRaw( unsigned char *dt)
{
    // Check for Press/Alti and Temp value ready
    if ( isDataAvailable() & PTDR_STATUS) {
        if ( MPL3115A2_mode == ALTIMETER_MODE) {
            getAltimeterRaw( &dt[0]);               // 3 bytes
        } else {
            getPressureRaw( &dt[0]);                   // 3 bytes
        }
        
        getTemperatureRaw( &dt[3]);                    // 2 bytes
        
        return 1;
    } else {
        return 0;
    }
}

unsigned int MPL3115A2::getAltimeterRaw( unsigned char *dt)
{
    
    /*
    * dt[0] = Bits 12-19 of 20-bit real-time Pressure sample. (b7-b0)
    * dt[1] = Bits 4-11 of 20-bit real-time Pressure sample. (b7-b0)
    * dt[2] = Bits 0-3 of 20-bit real-time Pressure sample (b7-b4)
    */
    
    // Check for Press/Alti value ready
    if ( isDataAvailable() & PDR_STATUS) {
        readRegs( REG_ALTIMETER_MSB, &dt[0], 3);    
        return 1;
    } else
        return 0;
}

unsigned int  MPL3115A2::getPressureRaw( unsigned char *dt)
{
    
    /*
    * dt[0] = Bits 12-19 of 20-bit real-time Pressure sample. (b7-b0)
    * dt[1] = Bits 4-11 of 20-bit real-time Pressure sample. (b7-b0)
    * dt[2] = Bits 0-3 of 20-bit real-time Pressure sample (b7-b4)
    */
    
    // Check for Press/Alti value ready
    if ( isDataAvailable() & PDR_STATUS) {
        readRegs( REG_PRESSURE_MSB, &dt[0], 3);
        return 1;
    } else 
        return 0;
        
}

unsigned int MPL3115A2::getTemperatureRaw( unsigned char *dt)
{
    
    /*
    * dt[0] = Bits 4-11 of 16-bit real-time temperature sample. (b7-b0)
    * dt[1] = Bits 0-3 of 16-bit real-time temperature sample. (b7-b4)
    */
    
    // Check for Temp value ready
    if ( isDataAvailable() & TDR_STATUS) {
        readRegs( REG_TEMP_MSB, &dt[0], 2);
        return 1;
    } else
        return 0;        
}

void MPL3115A2::readRegs(int addr, uint8_t * data, int len) {
    char t[1] = {addr};
    m_i2c.write(m_addr, t, 1, true);
    m_i2c.read(m_addr, (char *)data, len);
}

void MPL3115A2::writeRegs(uint8_t * data, int len) {
    m_i2c.write(m_addr, (char *)data, len);
}