This is a port from the library for Arduino provided by Sparkfun with their breakout board of the LSM9DS0. The original library can be found here: https://github.com/sparkfun/SparkFun_LSM9DS0_Arduino_Library/tree/V_1.0.1 It is also provided an AHRS example based on Madgwick, also a port from an Arduino example. All of this was tested on a Nucleo F411RE and a Sparkfun breakout board.
LSM9DS0_mbed.cpp
- Committer:
- olimexsmart
- Date:
- 2015-12-05
- Revision:
- 0:32b177f0030e
File content as of revision 0:32b177f0030e:
/* Code by @OlimexSmart - Luca Olivieri This is a port from the Sparkfun library provided with the breakout board of the LSM9DS0. Visit their github for full comments: https://github.com/sparkfun/SparkFun_LSM9DS0_Arduino_Library/tree/V_1.0.1 */ #include "LSM9DS0_mbed.h" LSM9DS0::LSM9DS0(PinName sdaP, PinName sclP, uint8_t gAddr, uint8_t xmAddr) { // xmAddress and gAddress will store the 7-bit I2C address. xmAddress = xmAddr; gAddress = gAddr; i2c_ = new I2C(sdaP, sclP); //This is initI2C(); in the original library i2c_->frequency(400000); } 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 } // This is a function that uses the FIFO to accumulate sample of accelerometer and gyro data, average // them, scales them to gs and deg/s, respectively, and then passes the biases to the main sketch // for subtraction from all subsequent data. There are no gyro and accelerometer bias registers to store // the data as there are in the ADXL345, a precursor to the LSM9DS0, or the MPU-9150, so we have to // subtract the biases ourselves. This results in a more accurate measurement in general and can // remove errors due to imprecise or varying initial placement. Calibration of sensor data in this manner // is good practice. 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 gReadBytes(OUT_X_L_G, &data[0], 6); 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 xmReadBytes(OUT_X_L_A, &data[0], 6); 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() { uint8_t temp[6]; // We'll read six bytes from the accelerometer into temp xmReadBytes(OUT_X_L_A, temp, 6); // Read 6 bytes, beginning at OUT_X_L_A ax = (temp[1] << 8) | temp[0]; // Store x-axis values into ax ay = (temp[3] << 8) | temp[2]; // Store y-axis values into ay az = (temp[5] << 8) | temp[4]; // Store z-axis values into az } void LSM9DS0::readMag() { uint8_t temp[6]; // We'll read six bytes from the mag into temp xmReadBytes(OUT_X_L_M, temp, 6); // Read 6 bytes, beginning at OUT_X_L_M mx = (temp[1] << 8) | temp[0]; // Store x-axis values into mx my = (temp[3] << 8) | temp[2]; // Store y-axis values into my mz = (temp[5] << 8) | temp[4]; // Store z-axis values into mz } void LSM9DS0::readTemp() { uint8_t temp[2]; // We'll read two bytes from the temperature sensor into temp xmReadBytes(OUT_TEMP_L_XM, temp, 2); // Read 2 bytes, beginning at OUT_TEMP_L_XM //temperature = (((int16_t) temp[1] << 12) | temp[0] << 4 ) >> 4; // Temperature is a 12-bit signed integer uint8_t xlo = temp[0]; int16_t xhi = temp[1]; xhi <<= 8; xhi |= xlo; temperature = xhi; } void LSM9DS0::readGyro() { uint8_t temp[6]; // We'll read six bytes from the gyro into temp gReadBytes(OUT_X_L_G, temp, 6); // Read 6 bytes, beginning at OUT_X_L_G gx = (temp[1] << 8) | temp[0]; // Store x-axis values into gx gy = (temp[3] << 8) | temp[2]; // Store y-axis values into gy gz = (temp[5] << 8) | temp[4]; // Store z-axis values into gz } 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::setAccelABW(accel_abw abwRate) { // 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 ABW bits: temp &= 0xFF^(0x3 << 7); // Then shift in our new ODR bits: temp |= (abwRate << 7); // And write the new register value back into CTRL_REG2_XM: xmWriteByte(CTRL_REG2_XM, temp); } 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); } //I2C rewritten to accomodate i2cdev instead of Wire (Arduino) void LSM9DS0::I2CwriteByte(uint8_t address, uint8_t subAddress, uint8_t data) { char dt[2]; // Initialize the Tx buffer dt[0] = subAddress; // Put slave register address in Tx buffer dt[1] = data; // Put data in Tx buffer i2c_->write(address << 1, dt, 2); // Send the Tx buffer } uint8_t LSM9DS0::I2CreadByte(uint8_t address, uint8_t subAddress) { i2c_->write(address << 1, (char*)&subAddress, 1, true); // Send request, but keep connection alive char dt = 0; i2c_->read(address << 1, &dt, 1); // Fill Rx buffer with result return dt; // Return data read from slave register } void LSM9DS0::I2CreadBytes(uint8_t address, uint8_t subAddress, uint8_t * dest, uint8_t count) { char sA = subAddress | 0x80; // Send the register to be read. OR with 0x80 to indicate multi-read. i2c_->write(address << 1, &sA, 1, true); // Send the Tx buffer, but keep connection alive i2c_->read(address << 1, (char*)dest, count); // Read bytes from slave register address }