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Dependencies:   mbed

Dependents:   RoboCup_2015

Fork of LSM9DS0 by Taylor Andrews

LSM9DS0.cpp

Committer:
randrews33
Date:
2015-01-11
Revision:
6:e6a15dcba942
Parent:
5:bf8f4e7c9905

File content as of revision 6:e6a15dcba942:

#include "LSM9DS0.h"

LSM9DS0::LSM9DS0(PinName sda, PinName scl, uint8_t gAddr, uint8_t xmAddr)
{
    // xmAddress and gAddress will store the 7-bit I2C address, if using I2C.
    xmAddress = xmAddr;
    gAddress = gAddr;
    
    i2c_ = new I2Cdev(sda, scl);
}

uint16_t LSM9DS0::begin(gyro_scale gScl, accel_scale aScl, mag_scale mScl, 
                        gyro_odr gODR, accel_odr aODR, mag_odr mODR)
{
    // Store the given scales in class variables. These scale variables
    // are used throughout to calculate the actual g's, DPS,and Gs's.
    gScale = gScl;
    aScale = aScl;
    mScale = mScl;
    
    // Once we have the scale values, we can calculate the resolution
    // of each sensor. That's what these functions are for. One for each sensor
    calcgRes(); // Calculate DPS / ADC tick, stored in gRes variable
    calcmRes(); // Calculate Gs / ADC tick, stored in mRes variable
    calcaRes(); // Calculate g / ADC tick, stored in aRes variable
    
    
    // To verify communication, we can read from the WHO_AM_I register of
    // each device. Store those in a variable so we can return them.
    uint8_t gTest = gReadByte(WHO_AM_I_G);      // Read the gyro WHO_AM_I
    uint8_t xmTest = xmReadByte(WHO_AM_I_XM);   // Read the accel/mag WHO_AM_I
    
    // Gyro initialization stuff:
    initGyro(); // This will "turn on" the gyro. Setting up interrupts, etc.
    setGyroODR(gODR); // Set the gyro output data rate and bandwidth.
    setGyroScale(gScale); // Set the gyro range
    
    // Accelerometer initialization stuff:
    initAccel(); // "Turn on" all axes of the accel. Set up interrupts, etc.
    setAccelODR(aODR); // Set the accel data rate.
    setAccelScale(aScale); // Set the accel range.
    
    // Magnetometer initialization stuff:
    initMag(); // "Turn on" all axes of the mag. Set up interrupts, etc.
    setMagODR(mODR); // Set the magnetometer output data rate.
    setMagScale(mScale); // Set the magnetometer's range.
    
    // Once everything is initialized, return the WHO_AM_I registers we read:
    return (xmTest << 8) | gTest;
}

void LSM9DS0::initGyro()
{

    gWriteByte(CTRL_REG1_G, 0x0F); // Normal mode, enable all axes
    gWriteByte(CTRL_REG2_G, 0x00); // Normal mode, high cutoff frequency
    gWriteByte(CTRL_REG3_G, 0x88);  //Interrupt enabled on both INT_G  and I2_DRDY
    gWriteByte(CTRL_REG4_G, 0x00); // Set scale to 245 dps
    gWriteByte(CTRL_REG5_G, 0x00); //Init default values
    
}

void LSM9DS0::initAccel()
{
    xmWriteByte(CTRL_REG0_XM, 0x00);  
    xmWriteByte(CTRL_REG1_XM, 0x57); // 50Hz data rate, x/y/z all enabled                                                
    xmWriteByte(CTRL_REG2_XM, 0x00); // Set scale to 2g
    xmWriteByte(CTRL_REG3_XM, 0x04); // Accelerometer data ready on INT1_XM (0x04)

}

void LSM9DS0::initMag()
{   
    xmWriteByte(CTRL_REG5_XM, 0x94); // Mag data rate - 100 Hz, enable temperature sensor
    xmWriteByte(CTRL_REG6_XM, 0x00); // Mag scale to +/- 2GS
    xmWriteByte(CTRL_REG7_XM, 0x00); // Continuous conversion mode
    xmWriteByte(CTRL_REG4_XM, 0x04); // Magnetometer data ready on INT2_XM (0x08)
    xmWriteByte(INT_CTRL_REG_M, 0x09); // Enable interrupts for mag, active-low, push-pull
}

void LSM9DS0::calLSM9DS0(float * gbias, float * abias)
{  
  uint8_t data[6] = {0, 0, 0, 0, 0, 0};
  int16_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0};
  int samples, ii;
  
  // First get gyro bias
  uint8_t c = gReadByte(CTRL_REG5_G);
  gWriteByte(CTRL_REG5_G, c | 0x40);         // Enable gyro FIFO  
  wait_ms(20);                                 // Wait for change to take effect
  gWriteByte(FIFO_CTRL_REG_G, 0x20 | 0x1F);  // Enable gyro FIFO stream mode and set watermark at 32 samples
  wait_ms(1000);  // delay 1000 milliseconds to collect FIFO samples
  
  samples = (gReadByte(FIFO_SRC_REG_G) & 0x1F); // Read number of stored samples

  for(ii = 0; ii < samples ; ii++) {            // Read the gyro data stored in the FIFO

    data[0] = gReadByte(OUT_X_L_G);
    data[1] = gReadByte(OUT_X_H_G);
    data[2] = gReadByte(OUT_Y_L_G);
    data[3] = gReadByte(OUT_Y_H_G);
    data[4] = gReadByte(OUT_Z_L_G);
    data[5] = gReadByte(OUT_Z_H_G);
  
    gyro_bias[0] += (((int16_t)data[1] << 8) | data[0]);
    gyro_bias[1] += (((int16_t)data[3] << 8) | data[2]);
    gyro_bias[2] += (((int16_t)data[5] << 8) | data[4]);
  }  

  gyro_bias[0] /= samples; // average the data
  gyro_bias[1] /= samples; 
  gyro_bias[2] /= samples; 
  
  gbias[0] = (float)gyro_bias[0]*gRes;  // Properly scale the data to get deg/s
  gbias[1] = (float)gyro_bias[1]*gRes;
  gbias[2] = (float)gyro_bias[2]*gRes;
  
  c = gReadByte(CTRL_REG5_G);
  gWriteByte(CTRL_REG5_G, c & ~0x40);  // Disable gyro FIFO  
  wait_ms(20);
  gWriteByte(FIFO_CTRL_REG_G, 0x00);   // Enable gyro bypass mode
  
  //  Now get the accelerometer biases
  c = xmReadByte(CTRL_REG0_XM);
  xmWriteByte(CTRL_REG0_XM, c | 0x40);      // Enable accelerometer FIFO  
  wait_ms(20);                                // Wait for change to take effect
  xmWriteByte(FIFO_CTRL_REG, 0x20 | 0x1F);  // Enable accelerometer FIFO stream mode and set watermark at 32 samples
  wait_ms(1000);  // delay 1000 milliseconds to collect FIFO samples

  samples = (xmReadByte(FIFO_SRC_REG) & 0x1F); // Read number of stored accelerometer samples

   for(ii = 0; ii < samples ; ii++) {          // Read the accelerometer data stored in the FIFO
   
    data[0] = xmReadByte(OUT_X_L_A);
    data[1] = xmReadByte(OUT_X_H_A);
    data[2] = xmReadByte(OUT_Y_L_A);
    data[3] = xmReadByte(OUT_Y_H_A);
    data[4] = xmReadByte(OUT_Z_L_A);
    data[5] = xmReadByte(OUT_Z_H_A);
    accel_bias[0] += (((int16_t)data[1] << 8) | data[0]);
    accel_bias[1] += (((int16_t)data[3] << 8) | data[2]);
    accel_bias[2] += (((int16_t)data[5] << 8) | data[4]) - (int16_t)(1./aRes); // Assumes sensor facing up!
  }  

  accel_bias[0] /= samples; // average the data
  accel_bias[1] /= samples; 
  accel_bias[2] /= samples; 
  
  abias[0] = (float)accel_bias[0]*aRes; // Properly scale data to get gs
  abias[1] = (float)accel_bias[1]*aRes;
  abias[2] = (float)accel_bias[2]*aRes;

  c = xmReadByte(CTRL_REG0_XM);
  xmWriteByte(CTRL_REG0_XM, c & ~0x40);    // Disable accelerometer FIFO  
  wait_ms(20);
  xmWriteByte(FIFO_CTRL_REG, 0x00);       // Enable accelerometer bypass mode
  
}
void LSM9DS0::readAccel()
{
  uint16_t Temp = 0;
  
  //Get x
  Temp = xmReadByte(OUT_X_H_A);
  Temp = Temp<<8;
  Temp |= xmReadByte(OUT_X_L_A);
  ax = Temp;
  
  
  //Get y
  Temp=0;
  Temp = xmReadByte(OUT_Y_H_A);
  Temp = Temp<<8;
  Temp |= xmReadByte(OUT_Y_L_A);
  ay = Temp;
  
  //Get z
  Temp=0;
  Temp = xmReadByte(OUT_Z_H_A);
  Temp = Temp<<8;
  Temp |= xmReadByte(OUT_Z_L_A);
  az = Temp;
  
}

void LSM9DS0::readMag()
{
  uint16_t Temp = 0;  

  //Get x
  Temp = xmReadByte(OUT_X_H_M);
  Temp = Temp<<8;
  Temp |= xmReadByte(OUT_X_L_M);
  mx = Temp;
  
  
  //Get y
  Temp=0;
  Temp = xmReadByte(OUT_Y_H_M);
  Temp = Temp<<8;
  Temp |= xmReadByte(OUT_Y_L_M);
  my = Temp;
  
  //Get z
  Temp=0;
  Temp = xmReadByte(OUT_Z_H_M);
  Temp = Temp<<8;
  Temp |= xmReadByte(OUT_Z_L_M);
  mz = Temp;
}

void LSM9DS0::readTemp()
{
    uint8_t temp[2]; // We'll read two bytes from the temperature sensor into temp  
    
    temp[0] = xmReadByte(OUT_TEMP_L_XM);
    temp[1] = xmReadByte(OUT_TEMP_H_XM);
    
    temperature = (((int16_t) temp[1] << 12) | temp[0] << 4 ) >> 4; // Temperature is a 12-bit signed integer
}


void LSM9DS0::readGyro()
{   
  uint16_t Temp = 0;

  //Get x
  Temp = gReadByte(OUT_X_H_G);
  Temp = Temp<<8;
  Temp |= gReadByte(OUT_X_L_G);
  gx = Temp;
  
  
  //Get y
  Temp=0;
  Temp = gReadByte(OUT_Y_H_G);
  Temp = Temp<<8;
  Temp |= gReadByte(OUT_Y_L_G);
  gy = Temp;
  
  //Get z
  Temp=0;
  Temp = gReadByte(OUT_Z_H_G);
  Temp = Temp<<8;
  Temp |= gReadByte(OUT_Z_L_G);
  gz = Temp;
}

float LSM9DS0::calcGyro(int16_t gyro)
{
    // Return the gyro raw reading times our pre-calculated DPS / (ADC tick):
    return gRes * gyro; 
}

float LSM9DS0::calcAccel(int16_t accel)
{
    // Return the accel raw reading times our pre-calculated g's / (ADC tick):
    return aRes * accel;
}

float LSM9DS0::calcMag(int16_t mag)
{
    // Return the mag raw reading times our pre-calculated Gs / (ADC tick):
    return mRes * mag;
}

void LSM9DS0::setGyroScale(gyro_scale gScl)
{
    // We need to preserve the other bytes in CTRL_REG4_G. So, first read it:
    uint8_t temp = gReadByte(CTRL_REG4_G);
    // Then mask out the gyro scale bits:
    temp &= 0xFF^(0x3 << 4);
    // Then shift in our new scale bits:
    temp |= gScl << 4;
    // And write the new register value back into CTRL_REG4_G:
    gWriteByte(CTRL_REG4_G, temp);
    
    // We've updated the sensor, but we also need to update our class variables
    // First update gScale:
    gScale = gScl;
    // Then calculate a new gRes, which relies on gScale being set correctly:
    calcgRes();
}

void LSM9DS0::setAccelScale(accel_scale aScl)
{
    // We need to preserve the other bytes in CTRL_REG2_XM. So, first read it:
    uint8_t temp = xmReadByte(CTRL_REG2_XM);
    // Then mask out the accel scale bits:
    temp &= 0xFF^(0x3 << 3);
    // Then shift in our new scale bits:
    temp |= aScl << 3;
    // And write the new register value back into CTRL_REG2_XM:
    xmWriteByte(CTRL_REG2_XM, temp);
    
    // We've updated the sensor, but we also need to update our class variables
    // First update aScale:
    aScale = aScl;
    // Then calculate a new aRes, which relies on aScale being set correctly:
    calcaRes();
}

void LSM9DS0::setMagScale(mag_scale mScl)
{
    // We need to preserve the other bytes in CTRL_REG6_XM. So, first read it:
    uint8_t temp = xmReadByte(CTRL_REG6_XM);
    // Then mask out the mag scale bits:
    temp &= 0xFF^(0x3 << 5);
    // Then shift in our new scale bits:
    temp |= mScl << 5;
    // And write the new register value back into CTRL_REG6_XM:
    xmWriteByte(CTRL_REG6_XM, temp);
    
    // We've updated the sensor, but we also need to update our class variables
    // First update mScale:
    mScale = mScl;
    // Then calculate a new mRes, which relies on mScale being set correctly:
    calcmRes();
}

void LSM9DS0::setGyroODR(gyro_odr gRate)
{
    // We need to preserve the other bytes in CTRL_REG1_G. So, first read it:
    uint8_t temp = gReadByte(CTRL_REG1_G);
    // Then mask out the gyro ODR bits:
    temp &= 0xFF^(0xF << 4);
    // Then shift in our new ODR bits:
    temp |= (gRate << 4);
    // And write the new register value back into CTRL_REG1_G:
    gWriteByte(CTRL_REG1_G, temp);
}
void LSM9DS0::setAccelODR(accel_odr aRate)
{
    // We need to preserve the other bytes in CTRL_REG1_XM. So, first read it:
    uint8_t temp = xmReadByte(CTRL_REG1_XM);
    // Then mask out the accel ODR bits:
    temp &= 0xFF^(0xF << 4);
    // Then shift in our new ODR bits:
    temp |= (aRate << 4);
    // And write the new register value back into CTRL_REG1_XM:
    xmWriteByte(CTRL_REG1_XM, temp);
}
void LSM9DS0::setMagODR(mag_odr mRate)
{
    // We need to preserve the other bytes in CTRL_REG5_XM. So, first read it:
    uint8_t temp = xmReadByte(CTRL_REG5_XM);
    // Then mask out the mag ODR bits:
    temp &= 0xFF^(0x7 << 2);
    // Then shift in our new ODR bits:
    temp |= (mRate << 2);
    // And write the new register value back into CTRL_REG5_XM:
    xmWriteByte(CTRL_REG5_XM, temp);
}

void LSM9DS0::configGyroInt(uint8_t int1Cfg, uint16_t int1ThsX, uint16_t int1ThsY, uint16_t int1ThsZ, uint8_t duration)
{
    gWriteByte(INT1_CFG_G, int1Cfg);
    gWriteByte(INT1_THS_XH_G, (int1ThsX & 0xFF00) >> 8);
    gWriteByte(INT1_THS_XL_G, (int1ThsX & 0xFF));
    gWriteByte(INT1_THS_YH_G, (int1ThsY & 0xFF00) >> 8);
    gWriteByte(INT1_THS_YL_G, (int1ThsY & 0xFF));
    gWriteByte(INT1_THS_ZH_G, (int1ThsZ & 0xFF00) >> 8);
    gWriteByte(INT1_THS_ZL_G, (int1ThsZ & 0xFF));
    if (duration)
        gWriteByte(INT1_DURATION_G, 0x80 | duration);
    else
        gWriteByte(INT1_DURATION_G, 0x00);
}

void LSM9DS0::calcgRes()
{
    // Possible gyro scales (and their register bit settings) are:
    // 245 DPS (00), 500 DPS (01), 2000 DPS (10). Here's a bit of an algorithm
    // to calculate DPS/(ADC tick) based on that 2-bit value:
    switch (gScale)
    {
    case G_SCALE_245DPS:
        gRes = 245.0 / 32768.0;
        break;
    case G_SCALE_500DPS:
        gRes = 500.0 / 32768.0;
        break;
    case G_SCALE_2000DPS:
        gRes = 2000.0 / 32768.0;
        break;
    }
}

void LSM9DS0::calcaRes()
{
    // Possible accelerometer scales (and their register bit settings) are:
    // 2 g (000), 4g (001), 6g (010) 8g (011), 16g (100). Here's a bit of an 
    // algorithm to calculate g/(ADC tick) based on that 3-bit value:
    aRes = aScale == A_SCALE_16G ? 16.0 / 32768.0 : 
           (((float) aScale + 1.0) * 2.0) / 32768.0;
}

void LSM9DS0::calcmRes()
{
    // Possible magnetometer scales (and their register bit settings) are:
    // 2 Gs (00), 4 Gs (01), 8 Gs (10) 12 Gs (11). Here's a bit of an algorithm
    // to calculate Gs/(ADC tick) based on that 2-bit value:
    mRes = mScale == M_SCALE_2GS ? 2.0 / 32768.0 : 
           (float) (mScale << 2) / 32768.0;
}
    
void LSM9DS0::gWriteByte(uint8_t subAddress, uint8_t data)
{
    // Whether we're using I2C or SPI, write a byte using the
    // gyro-specific I2C address or SPI CS pin.
    I2CwriteByte(gAddress, subAddress, data);
}

void LSM9DS0::xmWriteByte(uint8_t subAddress, uint8_t data)
{
    // Whether we're using I2C or SPI, write a byte using the
    // accelerometer-specific I2C address or SPI CS pin.
        return I2CwriteByte(xmAddress, subAddress, data);
}

uint8_t LSM9DS0::gReadByte(uint8_t subAddress)
{
        return I2CreadByte(gAddress, subAddress);
}

void LSM9DS0::gReadBytes(uint8_t subAddress, uint8_t * dest, uint8_t count)
{
    // Whether we're using I2C or SPI, read multiple bytes using the
    // gyro-specific I2C address.
        I2CreadBytes(gAddress, subAddress, dest, count);
}

uint8_t LSM9DS0::xmReadByte(uint8_t subAddress)
{
    // Whether we're using I2C or SPI, read a byte using the
    // accelerometer-specific I2C address.
        return I2CreadByte(xmAddress, subAddress);
}

void LSM9DS0::xmReadBytes(uint8_t subAddress, uint8_t * dest, uint8_t count)
{
    // read multiple bytes using the
    // accelerometer-specific I2C address.
    I2CreadBytes(xmAddress, subAddress, dest, count);
}


void LSM9DS0::I2CwriteByte(uint8_t address, uint8_t subAddress, uint8_t data)
{   
    i2c_->writeByte(address,subAddress,data);
}

uint8_t LSM9DS0::I2CreadByte(uint8_t address, uint8_t subAddress)
{
    char data[1]; // `data` will store the register data
    
    I2CreadBytes(address, subAddress,(uint8_t*)data, 1);
    return (uint8_t)data[0];

}

void LSM9DS0::I2CreadBytes(uint8_t address, uint8_t subAddress, uint8_t * dest,
                            uint8_t count)
{   
    i2c_->readBytes(address, subAddress, count, dest);
}