Revision 0:3a1dce39106c, committed 2015-01-26

Comitter:

aswild

Date:

Mon Jan 26 06:34:53 2015 +0000

Child:

1:7c1e26d377ed

Commit message:

make LSM9DS0 a library

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LSM9DS0.cpp	Mon Jan 26 06:34:53 2015 +0000
@@ -0,0 +1,450 @@
+#include "LSM9DS0.h"
+#include "math.h"
+
+LSM9DS0::LSM9DS0(PinName sda, PinName scl, uint8_t gAddr, uint8_t xmAddr) : i2c(sda, scl)
+{
+	// xmAddress and gAddress will store the 7-bit I2C address, if using I2C.
+	xmAddress = xmAddr;
+	gAddress = gAddr;
+}
+
+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::readAccel()
+{
+	uint16_t data = 0;
+
+	//Get x
+	data = xmReadByte(OUT_X_H_A);
+	data <<= 8;
+	data |= xmReadByte(OUT_X_L_A);
+	ax_raw = data;
+	ax = ax_raw * aRes;
+
+	//Get y
+	data=0;
+	data = xmReadByte(OUT_Y_H_A);
+	data <<= 8;
+	data |= xmReadByte(OUT_Y_L_A);
+	ay_raw = data;
+	ay = ay_raw * aRes;
+
+	//Get z
+	data=0;
+	data = xmReadByte(OUT_Z_H_A);
+	data <<= 8;
+	data |= xmReadByte(OUT_Z_L_A);
+	az_raw = data;
+	az = az_raw * aRes;
+}
+
+void LSM9DS0::readMag()
+{
+	uint16_t data = 0;  
+
+	//Get x
+	data = xmReadByte(OUT_X_H_M);
+	data <<= 8;
+	data |= xmReadByte(OUT_X_L_M);
+	mx_raw = data;
+	mx = mx_raw * mRes;
+
+	//Get y
+	data = xmReadByte(OUT_Y_H_M);
+	data <<= 8;
+	data |= xmReadByte(OUT_Y_L_M);
+	my_raw = data;
+	my = my_raw * mRes;
+
+	//Get z
+	data = xmReadByte(OUT_Z_H_M);
+	data <<= 8;
+	data |= xmReadByte(OUT_Z_L_M);
+	mz_raw = data;
+	mz = mz_raw * mRes;
+}
+
+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 is a 12-bit signed integer	
+	temperature_raw = (((int16_t) temp[1] << 12) | temp[0] << 4 ) >> 4;
+
+	temperature_c = (float)temperature_raw / 8.0;
+	temperature_f = temperature_c * 1.8 + 32;
+}
+
+
+void LSM9DS0::readGyro()
+{	
+	uint16_t data = 0;
+
+	//Get x
+	data = gReadByte(OUT_X_H_G);
+	data <<= 8;
+	data |= gReadByte(OUT_X_L_G);
+	gx_raw = data;
+	gx = gx_raw * gRes;
+
+	//Get y
+	data = gReadByte(OUT_Y_H_G);
+	data <<= 8;
+	data |= gReadByte(OUT_Y_L_G);
+	gy_raw = data;
+	gy = gy_raw * gRes;
+
+	//Get z
+	data = gReadByte(OUT_Z_H_G);
+	data <<= 8;
+	data |= gReadByte(OUT_Z_L_G);
+	gz_raw = data;
+	gz = gz_raw * gRes;
+}
+
+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;
+}
+
+#define R2D 57.295779513F
+// calculate compass heading, assuming readMag() has been called already
+float LSM9DS0::calcHeading()
+{
+	if (my > 0)
+		return 90.0 - atan(mx / my)*R2D;
+	else if (my < 0)
+		return 270.0 - atan(mx / my)*R2D;
+	else if (mx < 0)
+		return 180.0;
+	else
+		return 0.0;
+}
+	
+void LSM9DS0::calcBias()
+{  
+	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::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);
+}
+
+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::I2CwriteByte(char address, char subAddress, char data)
+{	
+	char cmd[2] = {subAddress, data};
+	i2c.write(address<<1, cmd, 2);
+
+}
+
+uint8_t LSM9DS0::I2CreadByte(char address, char subAddress)
+{
+	char data; // store the register data
+	i2c.write(address<<1, &subAddress, 1, true);
+	i2c.read(address<<1, &data, 1);
+	
+	return data;
+
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LSM9DS0.h	Mon Jan 26 06:34:53 2015 +0000
@@ -0,0 +1,462 @@
+// Most of the Credit goes to jimblom
+// Modifications by Allen Wild
+#ifndef _LSM9DS0_H__
+#define _LSM9DS0_H__
+
+#include "mbed.h"
+
+////////////////////////////
+// LSM9DS0 Gyro Registers //
+////////////////////////////
+#define WHO_AM_I_G          0x0F
+#define CTRL_REG1_G         0x20
+#define CTRL_REG2_G         0x21
+#define CTRL_REG3_G         0x22
+#define CTRL_REG4_G         0x23
+#define CTRL_REG5_G         0x24
+#define REFERENCE_G         0x25
+#define STATUS_REG_G        0x27
+#define OUT_X_L_G           0x28
+#define OUT_X_H_G           0x29
+#define OUT_Y_L_G           0x2A
+#define OUT_Y_H_G           0x2B
+#define OUT_Z_L_G           0x2C
+#define OUT_Z_H_G           0x2D
+#define FIFO_CTRL_REG_G     0x2E
+#define FIFO_SRC_REG_G      0x2F
+#define INT1_CFG_G          0x30
+#define INT1_SRC_G          0x31
+#define INT1_THS_XH_G       0x32
+#define INT1_THS_XL_G       0x33
+#define INT1_THS_YH_G       0x34
+#define INT1_THS_YL_G       0x35
+#define INT1_THS_ZH_G       0x36
+#define INT1_THS_ZL_G       0x37
+#define INT1_DURATION_G     0x38
+
+//////////////////////////////////////////
+// LSM9DS0 Accel/Magneto (XM) Registers //
+//////////////////////////////////////////
+#define OUT_TEMP_L_XM       0x05
+#define OUT_TEMP_H_XM       0x06
+#define STATUS_REG_M        0x07
+#define OUT_X_L_M           0x08
+#define OUT_X_H_M           0x09
+#define OUT_Y_L_M           0x0A
+#define OUT_Y_H_M           0x0B
+#define OUT_Z_L_M           0x0C
+#define OUT_Z_H_M           0x0D
+#define WHO_AM_I_XM         0x0F
+#define INT_CTRL_REG_M      0x12
+#define INT_SRC_REG_M       0x13
+#define INT_THS_L_M         0x14
+#define INT_THS_H_M         0x15
+#define OFFSET_X_L_M        0x16
+#define OFFSET_X_H_M        0x17
+#define OFFSET_Y_L_M        0x18
+#define OFFSET_Y_H_M        0x19
+#define OFFSET_Z_L_M        0x1A
+#define OFFSET_Z_H_M        0x1B
+#define REFERENCE_X         0x1C
+#define REFERENCE_Y         0x1D
+#define REFERENCE_Z         0x1E
+#define CTRL_REG0_XM        0x1F
+#define CTRL_REG1_XM        0x20
+#define CTRL_REG2_XM        0x21
+#define CTRL_REG3_XM        0x22
+#define CTRL_REG4_XM        0x23
+#define CTRL_REG5_XM        0x24
+#define CTRL_REG6_XM        0x25
+#define CTRL_REG7_XM        0x26
+#define STATUS_REG_A        0x27
+#define OUT_X_L_A           0x28
+#define OUT_X_H_A           0x29
+#define OUT_Y_L_A           0x2A
+#define OUT_Y_H_A           0x2B
+#define OUT_Z_L_A           0x2C
+#define OUT_Z_H_A           0x2D
+#define FIFO_CTRL_REG       0x2E
+#define FIFO_SRC_REG        0x2F
+#define INT_GEN_1_REG       0x30
+#define INT_GEN_1_SRC       0x31
+#define INT_GEN_1_THS       0x32
+#define INT_GEN_1_DURATION  0x33
+#define INT_GEN_2_REG       0x34
+#define INT_GEN_2_SRC       0x35
+#define INT_GEN_2_THS       0x36
+#define INT_GEN_2_DURATION  0x37
+#define CLICK_CFG           0x38
+#define CLICK_SRC           0x39
+#define CLICK_THS           0x3A
+#define TIME_LIMIT          0x3B
+#define TIME_LATENCY        0x3C
+#define TIME_WINDOW         0x3D
+#define ACT_THS             0x3E
+#define ACT_DUR             0x3F
+
+
+class LSM9DS0
+{
+public:
+
+    /// gyro_scale defines the possible full-scale ranges of the gyroscope:
+    enum gyro_scale
+    {
+        G_SCALE_245DPS,     // 00: +/- 245 degrees per second
+        G_SCALE_500DPS,     // 01: +/- 500 dps
+        G_SCALE_2000DPS,    // 10: +/- 2000 dps
+    };
+
+    /// accel_scale defines all possible FSR's of the accelerometer:
+    enum accel_scale
+    {
+        A_SCALE_2G, // 000: +/- 2g
+        A_SCALE_4G, // 001: +/- 4g
+        A_SCALE_6G, // 010: +/- 6g
+        A_SCALE_8G, // 011: +/- 8g
+        A_SCALE_16G // 100: +/- 16g
+    };
+
+    /// mag_scale defines all possible FSR's of the magnetometer:
+    enum mag_scale
+    {
+        M_SCALE_2GS,    // 00: +/- 2Gs
+        M_SCALE_4GS,    // 01: +/- 4Gs
+        M_SCALE_8GS,    // 10: +/- 8Gs
+        M_SCALE_12GS,   // 11: +/- 12Gs
+    };
+
+    /// gyro_odr defines all possible data rate/bandwidth combos of the gyro:
+    enum gyro_odr
+    {                           // ODR (Hz) --- Cutoff
+        G_ODR_95_BW_125  = 0x0, //   95         12.5
+        G_ODR_95_BW_25   = 0x1, //   95          25
+        // 0x2 and 0x3 define the same data rate and bandwidth
+        G_ODR_190_BW_125 = 0x4, //   190        12.5
+        G_ODR_190_BW_25  = 0x5, //   190         25
+        G_ODR_190_BW_50  = 0x6, //   190         50
+        G_ODR_190_BW_70  = 0x7, //   190         70
+        G_ODR_380_BW_20  = 0x8, //   380         20
+        G_ODR_380_BW_25  = 0x9, //   380         25
+        G_ODR_380_BW_50  = 0xA, //   380         50
+        G_ODR_380_BW_100 = 0xB, //   380         100
+        G_ODR_760_BW_30  = 0xC, //   760         30
+        G_ODR_760_BW_35  = 0xD, //   760         35
+        G_ODR_760_BW_50  = 0xE, //   760         50
+        G_ODR_760_BW_100 = 0xF, //   760         100
+    };
+
+    /// accel_oder defines all possible output data rates of the accelerometer:
+    enum accel_odr
+    {
+        A_POWER_DOWN,   // Power-down mode (0x0)
+        A_ODR_3125,     // 3.125 Hz (0x1)
+        A_ODR_625,      // 6.25 Hz (0x2)
+        A_ODR_125,      // 12.5 Hz (0x3)
+        A_ODR_25,       // 25 Hz (0x4)
+        A_ODR_50,       // 50 Hz (0x5)
+        A_ODR_100,      // 100 Hz (0x6)
+        A_ODR_200,      // 200 Hz (0x7)
+        A_ODR_400,      // 400 Hz (0x8)
+        A_ODR_800,      // 800 Hz (9)
+        A_ODR_1600      // 1600 Hz (0xA)
+    };
+    /// accel_oder defines all possible output data rates of the magnetometer:
+    enum mag_odr
+    {
+        M_ODR_3125, // 3.125 Hz (0x00)
+        M_ODR_625,  // 6.25 Hz (0x01)
+        M_ODR_125,  // 12.5 Hz (0x02)
+        M_ODR_25,   // 25 Hz (0x03)
+        M_ODR_50,   // 50 (0x04)
+        M_ODR_100,  // 100 Hz (0x05)
+    };
+
+    // We'll store the gyro, accel, and magnetometer readings in a series of
+    // public class variables. Each sensor gets three variables -- one for each
+    // axis. Call readGyro(), readAccel(), and readMag() first, before using
+    // these variables!
+    // These values are the RAW signed 16-bit readings from the sensors.
+    int16_t gx_raw, gy_raw, gz_raw; // x, y, and z axis readings of the gyroscope
+    int16_t ax_raw, ay_raw, az_raw; // x, y, and z axis readings of the accelerometer
+    int16_t mx_raw, my_raw, mz_raw; // x, y, and z axis readings of the magnetometer
+    int16_t temperature_raw;
+
+	// floating-point values of scaled data in real-world units
+	float gx, gy, gz;
+	float ax, ay, az;
+	float mx, my, mz;
+	float temperature_c, temperature_f; // temperature in celcius and fahrenheit
+
+    float abias[3];
+    float gbias[3];
+
+    
+    /**  LSM9DS0 -- LSM9DS0 class constructor
+    *  The constructor will set up a handful of private variables, and set the
+    *  communication mode as well.
+    *  Input:
+    *   - interface = Either MODE_SPI or MODE_I2C, whichever you're using
+    *               to talk to the IC.
+    *   - gAddr = If MODE_I2C, this is the I2C address of the gyroscope.
+    *               If MODE_SPI, this is the chip select pin of the gyro (CSG)
+    *   - xmAddr = If MODE_I2C, this is the I2C address of the accel/mag.
+    *               If MODE_SPI, this is the cs pin of the accel/mag (CSXM)
+	*/
+    LSM9DS0(PinName sda, PinName scl, uint8_t gAddr, uint8_t xmAddr);
+    
+    /**  begin() -- Initialize the gyro, accelerometer, and magnetometer.
+    *  This will set up the scale and output rate of each sensor. It'll also
+    *  "turn on" every sensor and every axis of every sensor.
+    *  Input:
+    *   - gScl = The scale of the gyroscope. This should be a gyro_scale value.
+    *   - aScl = The scale of the accelerometer. Should be a accel_scale value.
+    *   - mScl = The scale of the magnetometer. Should be a mag_scale value.
+    *   - gODR = Output data rate of the gyroscope. gyro_odr value.
+    *   - aODR = Output data rate of the accelerometer. accel_odr value.
+    *   - mODR = Output data rate of the magnetometer. mag_odr value.
+    *  Output: The function will return an unsigned 16-bit value. The most-sig
+    *       bytes of the output are the WHO_AM_I reading of the accel. The
+    *       least significant two bytes are the WHO_AM_I reading of the gyro.
+    *  All parameters have a defaulted value, so you can call just "begin()".
+    *  Default values are FSR's of: +/- 245DPS, 2g, 2Gs; ODRs of 95 Hz for 
+    *  gyro, 100 Hz for accelerometer, 100 Hz for magnetometer.
+    *  Use the return value of this function to verify communication.
+	*/
+    uint16_t begin(gyro_scale gScl = G_SCALE_245DPS, 
+                accel_scale aScl = A_SCALE_2G, mag_scale mScl = M_SCALE_2GS,
+                gyro_odr gODR = G_ODR_95_BW_125, accel_odr aODR = A_ODR_50, 
+                mag_odr mODR = M_ODR_50);
+    
+    /**  readGyro() -- Read the gyroscope output registers.
+    *  This function will read all six gyroscope output registers.
+    *  The readings are stored in the class' gx_raw, gy_raw, and gz_raw variables. Read
+    *  those _after_ calling readGyro().
+	*/
+    void readGyro();
+    
+    /**  readAccel() -- Read the accelerometer output registers.
+    *  This function will read all six accelerometer output registers.
+    *  The readings are stored in the class' ax_raw, ay_raw, and az_raw variables. Read
+    *  those _after_ calling readAccel().
+	*/
+    void readAccel();
+    
+    /**  readMag() -- Read the magnetometer output registers.
+    *  This function will read all six magnetometer output registers.
+    *  The readings are stored in the class' mx_raw, my_raw, and mz_raw variables. Read
+    *  those _after_ calling readMag().
+	*/
+    void readMag();
+    
+    /**  readTemp() -- Read the temperature output register.
+    *  This function will read two temperature output registers.
+    *  The combined readings are stored in the class' temperature variables. Read
+    *  those _after_ calling readTemp().
+	*/
+    void readTemp();
+    
+    /**  setGyroScale() -- Set the full-scale range of the gyroscope.
+    *  This function can be called to set the scale of the gyroscope to 
+    *  245, 500, or 200 degrees per second.
+    *  Input:
+    *   - gScl = The desired gyroscope scale. Must be one of three possible
+    *       values from the gyro_scale enum.
+	*/
+    void setGyroScale(gyro_scale gScl);
+    
+    /**  setAccelScale() -- Set the full-scale range of the accelerometer.
+    *  This function can be called to set the scale of the accelerometer to
+    *  2, 4, 6, 8, or 16 g's.
+    *  Input:
+    *   - aScl = The desired accelerometer scale. Must be one of five possible
+    *       values from the accel_scale enum.
+	*/
+    void setAccelScale(accel_scale aScl);
+    
+    /**  setMagScale() -- Set the full-scale range of the magnetometer.
+    *  This function can be called to set the scale of the magnetometer to
+    *  2, 4, 8, or 12 Gs.
+    *  Input:
+    *   - mScl = The desired magnetometer scale. Must be one of four possible
+    *       values from the mag_scale enum.
+	*/
+    void setMagScale(mag_scale mScl);
+    
+    /**  setGyroODR() -- Set the output data rate and bandwidth of the gyroscope
+    *  Input:
+    *   - gRate = The desired output rate and cutoff frequency of the gyro.
+    *       Must be a value from the gyro_odr enum (check above, there're 14).
+	*/
+    void setGyroODR(gyro_odr gRate);
+    
+    /**  setAccelODR() -- Set the output data rate of the accelerometer
+    *  Input:
+    *   - aRate = The desired output rate of the accel.
+    *       Must be a value from the accel_odr enum (check above, there're 11).
+	*/
+    void setAccelODR(accel_odr aRate);
+    
+    /**  setMagODR() -- Set the output data rate of the magnetometer
+    *  Input:
+    *   - mRate = The desired output rate of the mag.
+    *       Must be a value from the mag_odr enum (check above, there're 6).
+	*/
+    void setMagODR(mag_odr mRate);
+    
+    /**  configGyroInt() -- Configure the gyro interrupt output.
+    *  Triggers can be set to either rising above or falling below a specified
+    *  threshold. This function helps setup the interrupt configuration and 
+    *  threshold values for all axes.
+    *  Input:
+    *   - int1Cfg = A 8-bit value that is sent directly to the INT1_CFG_G
+    *       register. This sets AND/OR and high/low interrupt gen for each axis
+    *   - int1ThsX = 16-bit interrupt threshold value for x-axis
+    *   - int1ThsY = 16-bit interrupt threshold value for y-axis
+    *   - int1ThsZ = 16-bit interrupt threshold value for z-axis
+    *   - duration = Duration an interrupt holds after triggered. This value
+    *       is copied directly into the INT1_DURATION_G register.
+    *  Before using this function, read about the INT1_CFG_G register and
+    *  the related INT1* registers in the LMS9DS0 datasheet.
+	*/
+    void configGyroInt(uint8_t int1Cfg, uint16_t int1ThsX = 0,
+                          uint16_t int1ThsY = 0, uint16_t int1ThsZ = 0, 
+                          uint8_t duration = 0);
+                          
+    void calcBias();
+
+	*  return a comass heading (in degrees) using X/Y magnetometer data
+	float calcHeading();
+
+
+private:    
+    /**  xmAddress and gAddress store the I2C address
+    *  for each sensor.
+	*/
+    uint8_t xmAddress, gAddress;
+    
+    /**  gScale, aScale, and mScale store the current scale range for each 
+    *  sensor. Should be updated whenever that value changes.
+	*/
+    gyro_scale gScale;
+    accel_scale aScale;
+    mag_scale mScale;
+    
+    /**  gRes, aRes, and mRes store the current resolution for each sensor. 
+    *  Units of these values would be DPS (or g's or Gs's) per ADC tick.
+    *  This value is calculated as (sensor scale) / (2^15).
+	*/
+    float gRes, aRes, mRes;
+    
+    /**  initGyro() -- Sets up the gyroscope to begin reading.
+    *  This function steps through all five gyroscope control registers.
+    *  Upon exit, the following parameters will be set:
+    *   - CTRL_REG1_G = 0x0F: Normal operation mode, all axes enabled. 
+    *       95 Hz ODR, 12.5 Hz cutoff frequency.
+    *   - CTRL_REG2_G = 0x00: HPF set to normal mode, cutoff frequency
+    *       set to 7.2 Hz (depends on ODR).
+    *   - CTRL_REG3_G = 0x88: Interrupt enabled on INT_G (set to push-pull and
+    *       active high). Data-ready output enabled on DRDY_G.
+    *   - CTRL_REG4_G = 0x00: Continuous update mode. Data LSB stored in lower
+    *       address. Scale set to 245 DPS. SPI mode set to 4-wire.
+    *   - CTRL_REG5_G = 0x00: FIFO disabled. HPF disabled.
+	*/
+    void initGyro();
+    
+    /**  initAccel() -- Sets up the accelerometer to begin reading.
+    *  This function steps through all accelerometer related control registers.
+    *  Upon exit these registers will be set as:
+    *   - CTRL_REG0_XM = 0x00: FIFO disabled. HPF bypassed. Normal mode.
+    *   - CTRL_REG1_XM = 0x57: 100 Hz data rate. Continuous update.
+    *       all axes enabled.
+    *   - CTRL_REG2_XM = 0x00: +/- 2g scale. 773 Hz anti-alias filter BW.
+    *   - CTRL_REG3_XM = 0x04: Accel data ready signal on INT1_XM pin.
+	*/
+    void initAccel();
+    
+    /**  initMag() -- Sets up the magnetometer to begin reading.
+    *  This function steps through all magnetometer-related control registers.
+    *  Upon exit these registers will be set as:
+    *   - CTRL_REG4_XM = 0x04: Mag data ready signal on INT2_XM pin.
+    *   - CTRL_REG5_XM = 0x14: 100 Hz update rate. Low resolution. Interrupt
+    *       requests don't latch. Temperature sensor disabled.
+    *   - CTRL_REG6_XM = 0x00: +/- 2 Gs scale.
+    *   - CTRL_REG7_XM = 0x00: Continuous conversion mode. Normal HPF mode.
+    *   - INT_CTRL_REG_M = 0x09: Interrupt active-high. Enable interrupts.
+	*/
+    void initMag();
+    
+    /**  gReadByte() -- Reads a byte from a specified gyroscope register.
+    *  Input:
+    *   - subAddress = Register to be read from.
+    *  Output:
+    *   - An 8-bit value read from the requested address.
+	*/
+    uint8_t gReadByte(uint8_t subAddress);
+    
+    /**  gWriteByte() -- Write a byte to a register in the gyroscope.
+    *  Input:
+    *   - subAddress = Register to be written to.
+    *   - data = data to be written to the register.
+	*/
+    void gWriteByte(uint8_t subAddress, uint8_t data);
+    
+    /**  xmReadByte() -- Read a byte from a register in the accel/mag sensor
+    *  Input:
+    *   - subAddress = Register to be read from.
+    *  Output:
+    *   - An 8-bit value read from the requested register.
+	*/
+    uint8_t xmReadByte(uint8_t subAddress);
+    
+    /**  xmWriteByte() -- Write a byte to a register in the accel/mag sensor.
+    *  Input:
+    *   - subAddress = Register to be written to.
+    *   - data = data to be written to the register.
+	*/
+    void xmWriteByte(uint8_t subAddress, uint8_t data);
+    
+    /**  calcgRes() -- Calculate the resolution of the gyroscope.
+    *  This function will set the value of the gRes variable. gScale must
+    *  be set prior to calling this function.
+	*/
+    void calcgRes();
+    
+    /**  calcmRes() -- Calculate the resolution of the magnetometer.
+    *  This function will set the value of the mRes variable. mScale must
+    *  be set prior to calling this function.
+	*/
+    void calcmRes();
+    
+    /**  calcaRes() -- Calculate the resolution of the accelerometer.
+    *  This function will set the value of the aRes variable. aScale must
+    *  be set prior to calling this function.
+	*/
+    void calcaRes();
+    
+    
+    ///////////////////
+    // I2C Functions //
+    ///////////////////
+	I2C i2c;
+
+    
+    /**  I2CwriteByte() -- Write a byte out of I2C to a register in the device
+    *  Input:
+    *   - address = The 7-bit I2C address of the slave device.
+    *   - subAddress = The register to be written to.
+    *   - data = Byte to be written to the register.
+	*/
+    void I2CwriteByte(char address, char subAddress, char data);
+    
+    /**  I2CreadByte() -- Read a single byte from a register over I2C.
+    *  Input:
+    *   - address = The 7-bit I2C address of the slave device.
+    *   - subAddress = The register to be read from.
+    *  Output:
+    *   - The byte read from the requested address.
+	*/
+    uint8_t I2CreadByte(char address, char subAddress);
+};
+
+#endif // _LSM9DS0_H //