![](/media/cache/profiles/me.png.50x50_q85.jpg)
this program is designed for the CHITISAT's OBC, and is a prototype for the flight plan vs altitude
Dependencies: ADS1015 BMP280 SDFileSystem SENSOR mbed
MPU6050.h
- Committer:
- FannyCalle
- Date:
- 2018-08-17
- Revision:
- 5:05fd6249c21b
- Parent:
- 0:642a7818292a
File content as of revision 5:05fd6249c21b:
#ifndef MPU6050_H #define MPU6050_H #include "mbed.h" #include "math.h" // Define registers per MPU6050, Register Map and Descriptions, Rev 4.2, 08/19/2013 6 DOF Motion sensor fusion device // Invensense Inc., www.invensense.com // See also MPU-6050 Register Map and Descriptions, Revision 4.0, RM-MPU-6050A-00, 9/12/2012 for registers not listed in // above document; the MPU6050 and MPU 9150 are virtually identical but the latter has an on-board magnetic sensor // #define XGOFFS_TC 0x00 // Bit 7 PWR_MODE, bits 6:1 XG_OFFS_TC, bit 0 OTP_BNK_VLD #define YGOFFS_TC 0x01 #define ZGOFFS_TC 0x02 #define X_FINE_GAIN 0x03 // [7:0] fine gain #define Y_FINE_GAIN 0x04 #define Z_FINE_GAIN 0x05 #define XA_OFFSET_H 0x06 // User-defined trim values for accelerometer #define XA_OFFSET_L_TC 0x07 #define YA_OFFSET_H 0x08 #define YA_OFFSET_L_TC 0x09 #define ZA_OFFSET_H 0x0A #define ZA_OFFSET_L_TC 0x0B #define SELF_TEST_X 0x0D #define SELF_TEST_Y 0x0E #define SELF_TEST_Z 0x0F #define SELF_TEST_A 0x10 #define XG_OFFS_USRH 0x13 // User-defined trim values for gyroscope; supported in MPU-6050? #define XG_OFFS_USRL 0x14 #define YG_OFFS_USRH 0x15 #define YG_OFFS_USRL 0x16 #define ZG_OFFS_USRH 0x17 #define ZG_OFFS_USRL 0x18 #define SMPLRT_DIV 0x19 #define CONFIG 0x1A #define GYRO_CONFIG 0x1B #define ACCEL_CONFIG 0x1C #define FF_THR 0x1D // Free-fall #define FF_DUR 0x1E // Free-fall #define MOT_THR 0x1F // Motion detection threshold bits [7:0] #define MOT_DUR 0x20 // Duration counter threshold for motion interrupt generation, 1 kHz rate, LSB = 1 ms #define ZMOT_THR 0x21 // Zero-motion detection threshold bits [7:0] #define ZRMOT_DUR 0x22 // Duration counter threshold for zero motion interrupt generation, 16 Hz rate, LSB = 64 ms #define FIFO_EN 0x23 #define I2C_MST_CTRL 0x24 #define I2C_SLV0_ADDR 0x25 #define I2C_SLV0_REG 0x26 #define I2C_SLV0_CTRL 0x27 #define I2C_SLV1_ADDR 0x28 #define I2C_SLV1_REG 0x29 #define I2C_SLV1_CTRL 0x2A #define I2C_SLV2_ADDR 0x2B #define I2C_SLV2_REG 0x2C #define I2C_SLV2_CTRL 0x2D #define I2C_SLV3_ADDR 0x2E #define I2C_SLV3_REG 0x2F #define I2C_SLV3_CTRL 0x30 #define I2C_SLV4_ADDR 0x31 #define I2C_SLV4_REG 0x32 #define I2C_SLV4_DO 0x33 #define I2C_SLV4_CTRL 0x34 #define I2C_SLV4_DI 0x35 #define I2C_MST_STATUS 0x36 #define INT_PIN_CFG 0x37 #define INT_ENABLE 0x38 #define DMP_INT_STATUS 0x39 // Check DMP interrupt #define INT_STATUS 0x3A #define ACCEL_XOUT_H 0x3B #define ACCEL_XOUT_L 0x3C #define ACCEL_YOUT_H 0x3D #define ACCEL_YOUT_L 0x3E #define ACCEL_ZOUT_H 0x3F #define ACCEL_ZOUT_L 0x40 #define TEMP_OUT_H 0x41 #define TEMP_OUT_L 0x42 #define GYRO_XOUT_H 0x43 #define GYRO_XOUT_L 0x44 #define GYRO_YOUT_H 0x45 #define GYRO_YOUT_L 0x46 #define GYRO_ZOUT_H 0x47 #define GYRO_ZOUT_L 0x48 #define EXT_SENS_DATA_00 0x49 #define EXT_SENS_DATA_01 0x4A #define EXT_SENS_DATA_02 0x4B #define EXT_SENS_DATA_03 0x4C #define EXT_SENS_DATA_04 0x4D #define EXT_SENS_DATA_05 0x4E #define EXT_SENS_DATA_06 0x4F #define EXT_SENS_DATA_07 0x50 #define EXT_SENS_DATA_08 0x51 #define EXT_SENS_DATA_09 0x52 #define EXT_SENS_DATA_10 0x53 #define EXT_SENS_DATA_11 0x54 #define EXT_SENS_DATA_12 0x55 #define EXT_SENS_DATA_13 0x56 #define EXT_SENS_DATA_14 0x57 #define EXT_SENS_DATA_15 0x58 #define EXT_SENS_DATA_16 0x59 #define EXT_SENS_DATA_17 0x5A #define EXT_SENS_DATA_18 0x5B #define EXT_SENS_DATA_19 0x5C #define EXT_SENS_DATA_20 0x5D #define EXT_SENS_DATA_21 0x5E #define EXT_SENS_DATA_22 0x5F #define EXT_SENS_DATA_23 0x60 #define MOT_DETECT_STATUS 0x61 #define I2C_SLV0_DO 0x63 #define I2C_SLV1_DO 0x64 #define I2C_SLV2_DO 0x65 #define I2C_SLV3_DO 0x66 #define I2C_MST_DELAY_CTRL 0x67 #define SIGNAL_PATH_RESET 0x68 #define MOT_DETECT_CTRL 0x69 #define USER_CTRL 0x6A // Bit 7 enable DMP, bit 3 reset DMP #define PWR_MGMT_1 0x6B // Device defaults to the SLEEP mode #define PWR_MGMT_2 0x6C #define DMP_BANK 0x6D // Activates a specific bank in the DMP #define DMP_RW_PNT 0x6E // Set read/write pointer to a specific start address in specified DMP bank #define DMP_REG 0x6F // Register in DMP from which to read or to which to write #define DMP_REG_1 0x70 #define DMP_REG_2 0x71 #define FIFO_COUNTH 0x72 #define FIFO_COUNTL 0x73 #define FIFO_R_W 0x74 #define WHO_AM_I_MPU6050 0x75 // Should return 0x68 // Using the GY-521 breakout board, I set ADO to 0 by grounding through a 4k7 resistor // Seven-bit device address is 110100 for ADO = 0 and 110101 for ADO = 1 #define ADO 0 #if ADO #define MPU6050_ADDRESS 0x69<<1 // Device address when ADO = 1 #else #define MPU6050_ADDRESS 0x68<<1 // Device address when ADO = 0 #endif // Set initial input parameters enum Ascale { AFS_2G = 0, AFS_4G, AFS_8G, AFS_16G }; enum Gscale { GFS_250DPS = 0, GFS_500DPS, GFS_1000DPS, GFS_2000DPS }; // Specify sensor full scale int Gscale = GFS_250DPS; int Ascale = AFS_2G; //Set up I2C, (SDA,SCL) I2C i2c(PB_4,PA_7); DigitalOut myled(LED1); float aRes, gRes; // scale resolutions per LSB for the sensors // Pin definitions int intPin = 12; // These can be changed, 2 and 3 are the Arduinos ext int pins int16_t accelCount[3]; // Stores the 16-bit signed accelerometer sensor output float ax, ay, az; // Stores the real accel value in g's int16_t gyroCount[3]; // Stores the 16-bit signed gyro sensor output float gx, gy, gz; // Stores the real gyro value in degrees per seconds float gyroBias[3] = {0, 0, 0}, accelBias[3] = {0, 0, 0}; // Bias corrections for gyro and accelerometer int16_t tempCount; // Stores the real internal chip temperature in degrees Celsius float temperature; float SelfTest[6]; int delt_t = 0; // used to control display output rate int count = 0; // used to control display output rate // parameters for 6 DoF sensor fusion calculations float PI = 3.14159265358979323846f; float GyroMeasError = PI * (60.0f / 180.0f); // gyroscope measurement error in rads/s (start at 60 deg/s), then reduce after ~10 s to 3 float beta = sqrt(3.0f / 4.0f) * GyroMeasError; // compute beta float GyroMeasDrift = PI * (1.0f / 180.0f); // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s) float zeta = sqrt(3.0f / 4.0f) * GyroMeasDrift; // compute zeta, the other free parameter in the Madgwick scheme usually set to a small or zero value float pitch, yaw, roll; float deltat = 0.0f; // integration interval for both filter schemes int lastUpdate = 0, firstUpdate = 0, Now = 0; // used to calculate integration interval // used to calculate integration interval float q[4] = {1.0f, 0.0f, 0.0f, 0.0f}; // vector to hold quaternion class MPU6050 { protected: public: //=================================================================================================================== //====== Set of useful function to access acceleratio, gyroscope, and temperature data //=================================================================================================================== void writeByte(uint8_t address, uint8_t subAddress, uint8_t data) { char data_write[2]; data_write[0] = subAddress; data_write[1] = data; i2c.write(address, data_write, 2, 0); } char readByte(uint8_t address, uint8_t subAddress) { char data[1]; // `data` will store the register data char data_write[1]; data_write[0] = subAddress; i2c.write(address, data_write, 1, 1); // no stop i2c.read(address, data, 1, 0); return data[0]; } void readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest) { char data[14]; char data_write[1]; data_write[0] = subAddress; i2c.write(address, data_write, 1, 1); // no stop i2c.read(address, data, count, 0); for(int ii = 0; ii < count; ii++) { dest[ii] = data[ii]; } } void getGres() { switch (Gscale) { // Possible gyro scales (and their register bit settings) are: // 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS (11). // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value: case GFS_250DPS: gRes = 250.0/32768.0; break; case GFS_500DPS: gRes = 500.0/32768.0; break; case GFS_1000DPS: gRes = 1000.0/32768.0; break; case GFS_2000DPS: gRes = 2000.0/32768.0; break; } } void getAres() { switch (Ascale) { // Possible accelerometer scales (and their register bit settings) are: // 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs (11). // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value: case AFS_2G: aRes = 2.0/32768.0; break; case AFS_4G: aRes = 4.0/32768.0; break; case AFS_8G: aRes = 8.0/32768.0; break; case AFS_16G: aRes = 16.0/32768.0; break; } } void readAccelData(int16_t * destination) { uint8_t rawData[6]; // x/y/z accel register data stored here readBytes(MPU6050_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; } void readGyroData(int16_t * destination) { uint8_t rawData[6]; // x/y/z gyro register data stored here readBytes(MPU6050_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; } int16_t readTempData() { uint8_t rawData[2]; // x/y/z gyro register data stored here readBytes(MPU6050_ADDRESS, TEMP_OUT_H, 2, &rawData[0]); // Read the two raw data registers sequentially into data array return (int16_t)(((int16_t)rawData[0]) << 8 | rawData[1]) ; // Turn the MSB and LSB into a 16-bit value } // Configure the motion detection control for low power accelerometer mode void LowPowerAccelOnly() { // The sensor has a high-pass filter necessary to invoke to allow the sensor motion detection algorithms work properly // Motion detection occurs on free-fall (acceleration below a threshold for some time for all axes), motion (acceleration // above a threshold for some time on at least one axis), and zero-motion toggle (acceleration on each axis less than a // threshold for some time sets this flag, motion above the threshold turns it off). The high-pass filter takes gravity out // consideration for these threshold evaluations; otherwise, the flags would be set all the time! uint8_t c = readByte(MPU6050_ADDRESS, PWR_MGMT_1); writeByte(MPU6050_ADDRESS, PWR_MGMT_1, c & ~0x30); // Clear sleep and cycle bits [5:6] writeByte(MPU6050_ADDRESS, PWR_MGMT_1, c | 0x30); // Set sleep and cycle bits [5:6] to zero to make sure accelerometer is running c = readByte(MPU6050_ADDRESS, PWR_MGMT_2); writeByte(MPU6050_ADDRESS, PWR_MGMT_2, c & ~0x38); // Clear standby XA, YA, and ZA bits [3:5] writeByte(MPU6050_ADDRESS, PWR_MGMT_2, c | 0x00); // Set XA, YA, and ZA bits [3:5] to zero to make sure accelerometer is running c = readByte(MPU6050_ADDRESS, ACCEL_CONFIG); writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c & ~0x07); // Clear high-pass filter bits [2:0] // Set high-pass filter to 0) reset (disable), 1) 5 Hz, 2) 2.5 Hz, 3) 1.25 Hz, 4) 0.63 Hz, or 7) Hold writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c | 0x00); // Set ACCEL_HPF to 0; reset mode disbaling high-pass filter c = readByte(MPU6050_ADDRESS, CONFIG); writeByte(MPU6050_ADDRESS, CONFIG, c & ~0x07); // Clear low-pass filter bits [2:0] writeByte(MPU6050_ADDRESS, CONFIG, c | 0x00); // Set DLPD_CFG to 0; 260 Hz bandwidth, 1 kHz rate c = readByte(MPU6050_ADDRESS, INT_ENABLE); writeByte(MPU6050_ADDRESS, INT_ENABLE, c & ~0xFF); // Clear all interrupts writeByte(MPU6050_ADDRESS, INT_ENABLE, 0x40); // Enable motion threshold (bits 5) interrupt only // Motion detection interrupt requires the absolute value of any axis to lie above the detection threshold // for at least the counter duration writeByte(MPU6050_ADDRESS, MOT_THR, 0x80); // Set motion detection to 0.256 g; LSB = 2 mg writeByte(MPU6050_ADDRESS, MOT_DUR, 0x01); // Set motion detect duration to 1 ms; LSB is 1 ms @ 1 kHz rate wait_ms(10); // Add delay for accumulation of samples c = readByte(MPU6050_ADDRESS, ACCEL_CONFIG); writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c & ~0x07); // Clear high-pass filter bits [2:0] writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c | 0x07); // Set ACCEL_HPF to 7; hold the initial accleration value as a referance c = readByte(MPU6050_ADDRESS, PWR_MGMT_2); writeByte(MPU6050_ADDRESS, PWR_MGMT_2, c & ~0xC7); // Clear standby XA, YA, and ZA bits [3:5] and LP_WAKE_CTRL bits [6:7] writeByte(MPU6050_ADDRESS, PWR_MGMT_2, c | 0x47); // Set wakeup frequency to 5 Hz, and disable XG, YG, and ZG gyros (bits [0:2]) c = readByte(MPU6050_ADDRESS, PWR_MGMT_1); writeByte(MPU6050_ADDRESS, PWR_MGMT_1, c & ~0x20); // Clear sleep and cycle bit 5 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, c | 0x20); // Set cycle bit 5 to begin low power accelerometer motion interrupts } void resetMPU6050() { // reset device writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device wait_ms(10); } void initMPU6050() { // Initialize MPU6050 device // wake up device writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors wait_ms(10); // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt // get stable time source writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x01); // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001 // Configure Gyro and Accelerometer // Disable FSYNC and set accelerometer and gyro bandwidth to 44 and 42 Hz, respectively; // DLPF_CFG = bits 2:0 = 010; this sets the sample rate at 1 kHz for both // Maximum delay is 4.9 ms which is just over a 200 Hz maximum rate writeByte(MPU6050_ADDRESS, CONFIG, 0x03); // Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV) writeByte(MPU6050_ADDRESS, SMPLRT_DIV, 0x04); // Use a 200 Hz rate; the same rate set in CONFIG above // Set gyroscope full scale range // Range selects FS_SEL and AFS_SEL are 0 - 3, so 2-bit values are left-shifted into positions 4:3 uint8_t c = readByte(MPU6050_ADDRESS, GYRO_CONFIG); writeByte(MPU6050_ADDRESS, GYRO_CONFIG, c & ~0xE0); // Clear self-test bits [7:5] writeByte(MPU6050_ADDRESS, GYRO_CONFIG, c & ~0x18); // Clear AFS bits [4:3] writeByte(MPU6050_ADDRESS, GYRO_CONFIG, c | Gscale << 3); // Set full scale range for the gyro // Set accelerometer configuration c = readByte(MPU6050_ADDRESS, ACCEL_CONFIG); writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c & ~0xE0); // Clear self-test bits [7:5] writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c & ~0x18); // Clear AFS bits [4:3] writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c | Ascale << 3); // Set full scale range for the accelerometer // Configure Interrupts and Bypass Enable // Set interrupt pin active high, push-pull, and clear on read of INT_STATUS, enable I2C_BYPASS_EN so additional chips // can join the I2C bus and all can be controlled by the Arduino as master writeByte(MPU6050_ADDRESS, INT_PIN_CFG, 0x22); writeByte(MPU6050_ADDRESS, INT_ENABLE, 0x01); // Enable data ready (bit 0) interrupt } // Function which accumulates gyro and accelerometer data after device initialization. It calculates the average // of the at-rest readings and then loads the resulting offsets into accelerometer and gyro bias registers. void calibrateMPU6050(float * dest1, float * dest2) { uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data uint16_t ii, packet_count, fifo_count; int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0}; // reset device, reset all registers, clear gyro and accelerometer bias registers writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device wait_ms(10); // get stable time source // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001 writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x01); writeByte(MPU6050_ADDRESS, PWR_MGMT_2, 0x00); wait_ms(20); // Configure device for bias calculation writeByte(MPU6050_ADDRESS, INT_ENABLE, 0x00); // Disable all interrupts writeByte(MPU6050_ADDRESS, FIFO_EN, 0x00); // Disable FIFO writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x00); // Turn on internal clock source writeByte(MPU6050_ADDRESS, I2C_MST_CTRL, 0x00); // Disable I2C master writeByte(MPU6050_ADDRESS, USER_CTRL, 0x00); // Disable FIFO and I2C master modes writeByte(MPU6050_ADDRESS, USER_CTRL, 0x0C); // Reset FIFO and DMP wait_ms(1.5); // Configure MPU6050 gyro and accelerometer for bias calculation writeByte(MPU6050_ADDRESS, CONFIG, 0x01); // Set low-pass filter to 188 Hz writeByte(MPU6050_ADDRESS, SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz writeByte(MPU6050_ADDRESS, GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity uint16_t gyrosensitivity = 131; // = 131 LSB/degrees/sec uint16_t accelsensitivity = 16384; // = 16384 LSB/g // Configure FIFO to capture accelerometer and gyro data for bias calculation writeByte(MPU6050_ADDRESS, USER_CTRL, 0x40); // Enable FIFO writeByte(MPU6050_ADDRESS, FIFO_EN, 0x78); // Enable gyro and accelerometer sensors for FIFO (max size 1024 bytes in MPU-6050) wait_ms(8); // accumulate 80 samples in 80 milliseconds = 960 bytes // At end of sample accumulation, turn off FIFO sensor read writeByte(MPU6050_ADDRESS, FIFO_EN, 0x00); // Disable gyro and accelerometer sensors for FIFO readBytes(MPU6050_ADDRESS, FIFO_COUNTH, 2, &data[0]); // read FIFO sample count fifo_count = ((uint16_t)data[0] << 8) | data[1]; packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging for (ii = 0; ii < packet_count; ii++) { int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0}; readBytes(MPU6050_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1] ) ; // Form signed 16-bit integer for each sample in FIFO accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3] ) ; accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5] ) ; gyro_temp[0] = (int16_t) (((int16_t)data[6] << 8) | data[7] ) ; gyro_temp[1] = (int16_t) (((int16_t)data[8] << 8) | data[9] ) ; gyro_temp[2] = (int16_t) (((int16_t)data[10] << 8) | data[11]) ; accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases accel_bias[1] += (int32_t) accel_temp[1]; accel_bias[2] += (int32_t) accel_temp[2]; gyro_bias[0] += (int32_t) gyro_temp[0]; gyro_bias[1] += (int32_t) gyro_temp[1]; gyro_bias[2] += (int32_t) gyro_temp[2]; } accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases accel_bias[1] /= (int32_t) packet_count; accel_bias[2] /= (int32_t) packet_count; gyro_bias[0] /= (int32_t) packet_count; gyro_bias[1] /= (int32_t) packet_count; gyro_bias[2] /= (int32_t) packet_count; if(accel_bias[2] > 0L) {accel_bias[2] -= (int32_t) accelsensitivity;} // Remove gravity from the z-axis accelerometer bias calculation else {accel_bias[2] += (int32_t) accelsensitivity;} // Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup data[0] = (-gyro_bias[0]/4 >> 8) & 0xFF; // Divide by 4 to get 32.9 LSB per deg/s to conform to expected bias input format data[1] = (-gyro_bias[0]/4) & 0xFF; // Biases are additive, so change sign on calculated average gyro biases data[2] = (-gyro_bias[1]/4 >> 8) & 0xFF; data[3] = (-gyro_bias[1]/4) & 0xFF; data[4] = (-gyro_bias[2]/4 >> 8) & 0xFF; data[5] = (-gyro_bias[2]/4) & 0xFF; // Push gyro biases to hardware registers writeByte(MPU6050_ADDRESS, XG_OFFS_USRH, data[0]); writeByte(MPU6050_ADDRESS, XG_OFFS_USRL, data[1]); writeByte(MPU6050_ADDRESS, YG_OFFS_USRH, data[2]); writeByte(MPU6050_ADDRESS, YG_OFFS_USRL, data[3]); writeByte(MPU6050_ADDRESS, ZG_OFFS_USRH, data[4]); writeByte(MPU6050_ADDRESS, ZG_OFFS_USRL, data[5]); dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity; dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity; // Construct the accelerometer biases for push to the hardware accelerometer bias registers. These registers contain // factory trim values which must be added to the calculated accelerometer biases; on boot up these registers will hold // non-zero values. In addition, bit 0 of the lower byte must be preserved since it is used for temperature // compensation calculations. Accelerometer bias registers expect bias input as 2048 LSB per g, so that // the accelerometer biases calculated above must be divided by 8. int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases readBytes(MPU6050_ADDRESS, XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values accel_bias_reg[0] = (int16_t) ((int16_t)data[0] << 8) | data[1]; readBytes(MPU6050_ADDRESS, YA_OFFSET_H, 2, &data[0]); accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1]; readBytes(MPU6050_ADDRESS, ZA_OFFSET_H, 2, &data[0]); accel_bias_reg[2] = (int16_t) ((int16_t)data[0] << 8) | data[1]; uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis for(ii = 0; ii < 3; ii++) { if(accel_bias_reg[ii] & mask) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit } // Construct total accelerometer bias, including calculated average accelerometer bias from above accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale) accel_bias_reg[1] -= (accel_bias[1]/8); accel_bias_reg[2] -= (accel_bias[2]/8); data[0] = (accel_bias_reg[0] >> 8) & 0xFF; data[1] = (accel_bias_reg[0]) & 0xFF; data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers data[2] = (accel_bias_reg[1] >> 8) & 0xFF; data[3] = (accel_bias_reg[1]) & 0xFF; data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers data[4] = (accel_bias_reg[2] >> 8) & 0xFF; data[5] = (accel_bias_reg[2]) & 0xFF; data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers // Push accelerometer biases to hardware registers // writeByte(MPU6050_ADDRESS, XA_OFFSET_H, data[0]); // writeByte(MPU6050_ADDRESS, XA_OFFSET_L_TC, data[1]); // writeByte(MPU6050_ADDRESS, YA_OFFSET_H, data[2]); // writeByte(MPU6050_ADDRESS, YA_OFFSET_L_TC, data[3]); // writeByte(MPU6050_ADDRESS, ZA_OFFSET_H, data[4]); // writeByte(MPU6050_ADDRESS, ZA_OFFSET_L_TC, data[5]); // Output scaled accelerometer biases for manual subtraction in the main program dest2[0] = (float)accel_bias[0]/(float)accelsensitivity; dest2[1] = (float)accel_bias[1]/(float)accelsensitivity; dest2[2] = (float)accel_bias[2]/(float)accelsensitivity; } // Accelerometer and gyroscope self test; check calibration wrt factory settings void MPU6050SelfTest(float * destination) // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass { uint8_t rawData[4] = {0, 0, 0, 0}; uint8_t selfTest[6]; float factoryTrim[6]; // Configure the accelerometer for self-test writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, 0xF0); // Enable self test on all three axes and set accelerometer range to +/- 8 g writeByte(MPU6050_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s wait_ms(0.25); // Delay a while to let the device execute the self-test rawData[0] = readByte(MPU6050_ADDRESS, SELF_TEST_X); // X-axis self-test results rawData[1] = readByte(MPU6050_ADDRESS, SELF_TEST_Y); // Y-axis self-test results rawData[2] = readByte(MPU6050_ADDRESS, SELF_TEST_Z); // Z-axis self-test results rawData[3] = readByte(MPU6050_ADDRESS, SELF_TEST_A); // Mixed-axis self-test results // Extract the acceleration test results first selfTest[0] = (rawData[0] >> 3) | (rawData[3] & 0x30) >> 4 ; // XA_TEST result is a five-bit unsigned integer selfTest[1] = (rawData[1] >> 3) | (rawData[3] & 0x0C) >> 4 ; // YA_TEST result is a five-bit unsigned integer selfTest[2] = (rawData[2] >> 3) | (rawData[3] & 0x03) >> 4 ; // ZA_TEST result is a five-bit unsigned integer // Extract the gyration test results first selfTest[3] = rawData[0] & 0x1F ; // XG_TEST result is a five-bit unsigned integer selfTest[4] = rawData[1] & 0x1F ; // YG_TEST result is a five-bit unsigned integer selfTest[5] = rawData[2] & 0x1F ; // ZG_TEST result is a five-bit unsigned integer // Process results to allow final comparison with factory set values factoryTrim[0] = (4096.0f*0.34f)*(pow( (0.92f/0.34f) , ((selfTest[0] - 1.0f)/30.0f))); // FT[Xa] factory trim calculation factoryTrim[1] = (4096.0f*0.34f)*(pow( (0.92f/0.34f) , ((selfTest[1] - 1.0f)/30.0f))); // FT[Ya] factory trim calculation factoryTrim[2] = (4096.0f*0.34f)*(pow( (0.92f/0.34f) , ((selfTest[2] - 1.0f)/30.0f))); // FT[Za] factory trim calculation factoryTrim[3] = ( 25.0f*131.0f)*(pow( 1.046f , (selfTest[3] - 1.0f) )); // FT[Xg] factory trim calculation factoryTrim[4] = (-25.0f*131.0f)*(pow( 1.046f , (selfTest[4] - 1.0f) )); // FT[Yg] factory trim calculation factoryTrim[5] = ( 25.0f*131.0f)*(pow( 1.046f , (selfTest[5] - 1.0f) )); // FT[Zg] factory trim calculation // Output self-test results and factory trim calculation if desired // Serial.println(selfTest[0]); Serial.println(selfTest[1]); Serial.println(selfTest[2]); // Serial.println(selfTest[3]); Serial.println(selfTest[4]); Serial.println(selfTest[5]); // Serial.println(factoryTrim[0]); Serial.println(factoryTrim[1]); Serial.println(factoryTrim[2]); // Serial.println(factoryTrim[3]); Serial.println(factoryTrim[4]); Serial.println(factoryTrim[5]); // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response // To get to percent, must multiply by 100 and subtract result from 100 for (int i = 0; i < 6; i++) { destination[i] = 100.0f + 100.0f*(selfTest[i] - factoryTrim[i])/factoryTrim[i]; // Report percent differences } } // Implementation of Sebastian Madgwick's "...efficient orientation filter for... inertial/magnetic sensor arrays" // (see http://www.x-io.co.uk/category/open-source/ for examples and more details) // which fuses acceleration and rotation rate to produce a quaternion-based estimate of relative // device orientation -- which can be converted to yaw, pitch, and roll. Useful for stabilizing quadcopters, etc. // The performance of the orientation filter is at least as good as conventional Kalman-based filtering algorithms // but is much less computationally intensive---it can be performed on a 3.3 V Pro Mini operating at 8 MHz! void MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz) { float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability float norm; // vector norm float f1, f2, f3; // objective funcyion elements float J_11or24, J_12or23, J_13or22, J_14or21, J_32, J_33; // objective function Jacobian elements float qDot1, qDot2, qDot3, qDot4; float hatDot1, hatDot2, hatDot3, hatDot4; float gerrx, gerry, gerrz, gbiasx, gbiasy, gbiasz; // gyro bias error // Auxiliary variables to avoid repeated arithmetic float _halfq1 = 0.5f * q1; float _halfq2 = 0.5f * q2; float _halfq3 = 0.5f * q3; float _halfq4 = 0.5f * q4; float _2q1 = 2.0f * q1; float _2q2 = 2.0f * q2; float _2q3 = 2.0f * q3; float _2q4 = 2.0f * q4; // float _2q1q3 = 2.0f * q1 * q3; // float _2q3q4 = 2.0f * q3 * q4; // Normalise accelerometer measurement norm = sqrt(ax * ax + ay * ay + az * az); if (norm == 0.0f) return; // handle NaN norm = 1.0f/norm; ax *= norm; ay *= norm; az *= norm; // Compute the objective function and Jacobian f1 = _2q2 * q4 - _2q1 * q3 - ax; f2 = _2q1 * q2 + _2q3 * q4 - ay; f3 = 1.0f - _2q2 * q2 - _2q3 * q3 - az; J_11or24 = _2q3; J_12or23 = _2q4; J_13or22 = _2q1; J_14or21 = _2q2; J_32 = 2.0f * J_14or21; J_33 = 2.0f * J_11or24; // Compute the gradient (matrix multiplication) hatDot1 = J_14or21 * f2 - J_11or24 * f1; hatDot2 = J_12or23 * f1 + J_13or22 * f2 - J_32 * f3; hatDot3 = J_12or23 * f2 - J_33 *f3 - J_13or22 * f1; hatDot4 = J_14or21 * f1 + J_11or24 * f2; // Normalize the gradient norm = sqrt(hatDot1 * hatDot1 + hatDot2 * hatDot2 + hatDot3 * hatDot3 + hatDot4 * hatDot4); hatDot1 /= norm; hatDot2 /= norm; hatDot3 /= norm; hatDot4 /= norm; // Compute estimated gyroscope biases gerrx = _2q1 * hatDot2 - _2q2 * hatDot1 - _2q3 * hatDot4 + _2q4 * hatDot3; gerry = _2q1 * hatDot3 + _2q2 * hatDot4 - _2q3 * hatDot1 - _2q4 * hatDot2; gerrz = _2q1 * hatDot4 - _2q2 * hatDot3 + _2q3 * hatDot2 - _2q4 * hatDot1; // Compute and remove gyroscope biases gbiasx += gerrx * deltat * zeta; gbiasy += gerry * deltat * zeta; gbiasz += gerrz * deltat * zeta; // gx -= gbiasx; // gy -= gbiasy; // gz -= gbiasz; // Compute the quaternion derivative qDot1 = -_halfq2 * gx - _halfq3 * gy - _halfq4 * gz; qDot2 = _halfq1 * gx + _halfq3 * gz - _halfq4 * gy; qDot3 = _halfq1 * gy - _halfq2 * gz + _halfq4 * gx; qDot4 = _halfq1 * gz + _halfq2 * gy - _halfq3 * gx; // Compute then integrate estimated quaternion derivative q1 += (qDot1 -(beta * hatDot1)) * deltat; q2 += (qDot2 -(beta * hatDot2)) * deltat; q3 += (qDot3 -(beta * hatDot3)) * deltat; q4 += (qDot4 -(beta * hatDot4)) * deltat; // Normalize the quaternion norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); // normalise quaternion norm = 1.0f/norm; q[0] = q1 * norm; q[1] = q2 * norm; q[2] = q3 * norm; q[3] = q4 * norm; } }; #endif