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Dependencies: HC_SR04_Ultrasonic_Library QEI mbed ros_lib_kinetic_weber
Fork of MPU6050IMU by
Diff: main.cpp
- Revision:
- 0:65aa78c10981
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diff -r 000000000000 -r 65aa78c10981 main.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Sun May 25 04:51:50 2014 +0000 @@ -0,0 +1,820 @@ +#include "mbed.h" + +/* MPU6050 Basic Example Code + by: Kris Winer + date: May 1, 2014 + license: Beerware - Use this code however you'd like. If you + find it useful you can buy me a beer some time. + + Demonstrate MPU-6050 basic functionality including initialization, accelerometer trimming, sleep mode functionality as well as + parameterizing the register addresses. Added display functions to allow display to on breadboard monitor. + No DMP use. We just want to get out the accelerations, temperature, and gyro readings. + + SDA and SCL should have external pull-up resistors (to 3.3V). + 10k resistors worked for me. They should be on the breakout + board. + + Hardware setup: + MPU6050 Breakout --------- Arduino + 3.3V --------------------- 3.3V + SDA ----------------------- A4 + SCL ----------------------- A5 + GND ---------------------- GND + + Note: The MPU6050 is an I2C sensor and uses the Arduino Wire library. + Because the sensor is not 5V tolerant, we are using a 3.3 V 8 MHz Pro Mini or a 3.3 V Teensy 3.1. + We have disabled the internal pull-ups used by the Wire library in the Wire.h/twi.c utility file. + We are also using the 400 kHz fast I2C mode by setting the TWI_FREQ to 400000L /twi.h utility file. + */ + +//#include <Wire.h> +//#include <Adafruit_GFX.h> +//#include <Adafruit_PCD8544.h> + +// Using NOKIA 5110 monochrome 84 x 48 pixel display +// pin 9 - Serial clock out (SCLK) +// pin 8 - Serial data out (DIN) +// pin 7 - Data/Command select (D/C) +// pin 5 - LCD chip select (CS) +// pin 6 - LCD reset (RST) +//Adafruit_PCD8544 display = Adafruit_PCD8544(9, 8, 7, 5, 6); + +// 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 // Device address when ADO = 1 +#else +#define MPU6050_ADDRESS 0x68 // Device address when ADO = 0 +#endif + +// Set up I2C +I2C i2c(PB_9, PB_8); +//i2c.frequency(400000); // use fast (400 kHz) I2C + +// Set up serial port +Serial pc(PA_2, PA_3); // PA_2, PA_3 on STM32F01 Nucleo + +Timer t; + +// 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; +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 +char blinkOn = false; + +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]; + +uint32_t delt_t = 0; // used to control display output rate +uint32_t count = 0; // used to control display output rate + +// parameters for 6 DoF sensor fusion calculations +float PI = 3.141593; +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 * (0.0f / 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 +uint32_t lastUpdate = 0, firstUpdate = 0; // used to calculate integration interval +uint32_t Now = 0; // used to calculate integration interval +float q[4] = {1.0f, 0.0f, 0.0f, 0.0f}; // vector to hold quaternion + +DigitalOut myled(LED1); + +//=================================================================================================================== +//====== Set of useful function to access acceleratio, gyroscope, and temperature data +//=================================================================================================================== + + void writeByte(uint8_t address, uint8_t subAddress, uint8_t data) +{ + i2c.write(address); + i2c.write(subAddress); + i2c.write(data); +} + + uint8_t readByte(uint8_t address, uint8_t subAddress) +{ + uint8_t data; // `data` will store the register data + i2c.write(address); + i2c.write(subAddress); + data = i2c.read(1); // read the length byte and the 7 databytes + return data; // Return data read from slave register +} + + void readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest) +{ + i2c.write(address); + i2c.write(subAddress); + for (int ii = 0; ii < count; ii++) { + dest[ii] = i2c.read(1); + } + +} +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)((rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value + destination[1] = (int16_t)((rawData[2] << 8) | rawData[3]) ; + destination[2] = (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)((rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value + destination[1] = (int16_t)((rawData[2] << 8) | rawData[3]) ; + destination[2] = (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)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 LowPowerAccelOnlyMPU6050() +{ + +// 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(0.1); // 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 initMPU6050() +{ + // Initialize MPU6050 device + // reset device + writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device + wait(0.1); + + // wake up device + writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors + wait(0.1); // 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 + uint8_t ii, fifo_count, packet_count; + int16_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(0.1); + +// 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(0.2); + +// 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(0.015); + +// 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 + wait(0.2); + + 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(0.08); // 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); // 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++) { + readBytes(MPU6050_ADDRESS, FIFO_R_W, 12, data); // read data for averaging + accel_bias[0] += (((int16_t)data[0] << 8) | data[1] ) ; // Divide sum of FIFO gyro data by number of samples + accel_bias[1] += (((int16_t)data[2] << 8) | data[3] ) ; + accel_bias[2] += (((int16_t)data[4] << 8) | data[5] ) - accelsensitivity; // Assumes device facing up! + gyro_bias[0] += (((int16_t)data[6] << 8) | data[7] ) ; + gyro_bias[1] += (((int16_t)data[8] << 8) | data[9] ) ; + gyro_bias[2] += (((int16_t)data[10] << 8) | data[11]) ; +} + + accel_bias[0] /= packet_count; // Normalize sums to get average count biases + accel_bias[1] /= packet_count; + accel_bias[2] /= packet_count; + gyro_bias[0] /= packet_count; + gyro_bias[1] /= packet_count; + gyro_bias[2] /= packet_count; + +// 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]); // might not be supported in MPU6050 +// 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. + + int16_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)data[0] << 8) | data[1]; + readBytes(MPU6050_ADDRESS, YA_OFFSET_H, 2, &data[0]); + accel_bias_reg[1] = ((int16_t)data[0] << 8) | data[1]; + readBytes(MPU6050_ADDRESS, ZA_OFFSET_H, 2, &data[0]); + accel_bias_reg[2] = ((int16_t)data[0] << 8) | data[1]; + + int16_t mask = 0x0001; // 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]); // might not be supported in MPU6050 +// 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]; + 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(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] = (4096.0*0.34)*(pow( (0.92/0.34) , ((selfTest[0] - 1.0)/30.0))); // FT[Xa] factory trim calculation + factoryTrim[1] = (4096.0*0.34)*(pow( (0.92/0.34) , ((selfTest[1] - 1.0)/30.0))); // FT[Ya] factory trim calculation + factoryTrim[2] = (4096.0*0.34)*(pow( (0.92/0.34) , ((selfTest[2] - 1.0)/30.0))); // FT[Za] factory trim calculation + factoryTrim[3] = ( 25.0*131.0)*(pow( 1.046 , (selfTest[3] - 1.0) )); // FT[Xg] factory trim calculation + factoryTrim[4] = (-25.0*131.0)*(pow( 1.046 , (selfTest[4] - 1.0) )); // FT[Yg] factory trim calculation + factoryTrim[5] = ( 25.0*131.0)*(pow( 1.046 , (selfTest[5] - 1.0) )); // 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] = 100.0 + 100.0*(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; // objetive 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; + } + + +void setup() +{ + + // Read the WHO_AM_I register, this is a good test of communication + uint8_t c = readByte(MPU6050_ADDRESS, WHO_AM_I_MPU6050); // Read WHO_AM_I register for MPU-6050 + + if (c == 0x68) // WHO_AM_I should always be 0x68 + { + pc.printf("MPU6050 is online..."); + + MPU6050SelfTest(SelfTest); // Start by performing self test and reporting values + pc.printf("x-axis self test: acceleration trim within : "); pc.printf("%f", SelfTest[0]); pc.printf("% of factory value"); + pc.printf("y-axis self test: acceleration trim within : "); pc.printf("%f", SelfTest[1]); pc.printf("% of factory value"); + pc.printf("z-axis self test: acceleration trim within : "); pc.printf("%f", SelfTest[2]); pc.printf("% of factory value"); + pc.printf("x-axis self test: gyration trim within : "); pc.printf("%f", SelfTest[3]); pc.printf("% of factory value"); + pc.printf("y-axis self test: gyration trim within : "); pc.printf("%f", SelfTest[4]); pc.printf("% of factory value"); + pc.printf("z-axis self test: gyration trim within : "); pc.printf("%f", SelfTest[5]); pc.printf("% of factory value"); + + if(SelfTest[0] < 1.0f && SelfTest[1] < 1.0f && SelfTest[2] < 1.0f && SelfTest[3] < 1.0f && SelfTest[4] < 1.0f && SelfTest[5] < 1.0f) { + + calibrateMPU6050(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers + initMPU6050(); pc.printf("MPU6050 initialized for active data mode...."); // Initialize device for active mode read of acclerometer, gyroscope, and temperature + } + else + { + pc.printf("Could not connect to MPU6050: 0x"); + pc.printf("%h", c); + while(1) ; // Loop forever if communication doesn't happen + } +} +} + + +int main() +{ + // If data ready bit set, all data registers have new data + if(readByte(MPU6050_ADDRESS, INT_STATUS) & 0x01) { // check if data ready interrupt + readAccelData(accelCount); // Read the x/y/z adc values + getAres(); + + // Now we'll calculate the accleration value into actual g's + ax = (float)accelCount[0]*aRes - accelBias[0]; // get actual g value, this depends on scale being set + ay = (float)accelCount[1]*aRes - accelBias[1]; + az = (float)accelCount[2]*aRes - accelBias[2]; + + readGyroData(gyroCount); // Read the x/y/z adc values + getGres(); + + // Calculate the gyro value into actual degrees per second + gx = (float)gyroCount[0]*gRes - gyroBias[0]; // get actual gyro value, this depends on scale being set + gy = (float)gyroCount[1]*gRes - gyroBias[1]; + gz = (float)gyroCount[2]*gRes - gyroBias[2]; + + tempCount = readTempData(); // Read the x/y/z adc values + temperature = (tempCount) / 340. + 36.53; // Temperature in degrees Centigrade + } + + Now = t.read_us(); + deltat = ((Now - lastUpdate)/1000000.0f); // set integration time by time elapsed since last filter update + lastUpdate = Now; + if(lastUpdate - firstUpdate > 10000000.0f) { + beta = 0.04; // decrease filter gain after stabilized + zeta = 0.015; // increaseyro bias drift gain after stabilized + } + // Pass gyro rate as rad/s + MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f); + + // Serial print and/or display at 0.5 s rate independent of data rates + delt_t = t.read_ms() - count; + if (delt_t > 500) { // update LCD once per half-second independent of read rate + // DigitalOut(LED1); + + pc.printf("ax = "); pc.printf("%i", 1000*ax); + pc.printf(" ay = "); pc.printf("%i", 1000*ay); + pc.printf(" az = "); pc.printf("%i", 1000*az); pc.printf(" mg"); + + pc.printf("gx = "); pc.printf("%f", gx); + pc.printf(" gy = "); pc.printf("%f", gy); + pc.printf(" gz = "); pc.printf("%f", gz); pc.printf(" deg/s"); + + pc.printf("q0 = "); pc.printf("%f", q[0]); + pc.printf(" qx = "); pc.printf("%f", q[1]); + pc.printf(" qy = "); pc.printf("%f", q[2]); + pc.printf(" qz = "); pc.printf("%f", q[3]); + + // Define output variables from updated quaternion---these are Tait-Bryan angles, commonly used in aircraft orientation. + // In this coordinate system, the positive z-axis is down toward Earth. + // Yaw is the angle between Sensor x-axis and Earth magnetic North (or true North if corrected for local declination, looking down on the sensor positive yaw is counterclockwise. + // Pitch is angle between sensor x-axis and Earth ground plane, toward the Earth is positive, up toward the sky is negative. + // Roll is angle between sensor y-axis and Earth ground plane, y-axis up is positive roll. + // These arise from the definition of the homogeneous rotation matrix constructed from quaternions. + // Tait-Bryan angles as well as Euler angles are non-commutative; that is, the get the correct orientation the rotations must be + // applied in the correct order which for this configuration is yaw, pitch, and then roll. + // For more see http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles which has additional links. + yaw = atan2(2.0f * (q[1] * q[2] + q[0] * q[3]), q[0] * q[0] + q[1] * q[1] - q[2] * q[2] - q[3] * q[3]); + pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2])); + roll = atan2(2.0f * (q[0] * q[1] + q[2] * q[3]), q[0] * q[0] - q[1] * q[1] - q[2] * q[2] + q[3] * q[3]); + pitch *= 180.0f / PI; + yaw *= 180.0f / PI; + roll *= 180.0f / PI; + + pc.printf("Yaw, Pitch, Roll: "); + pc.printf("%f", yaw); + pc.printf(", "); + pc.printf("%f", pitch); + pc.printf(", "); + pc.printf("%f", roll); + + pc.printf("average rate = "); pc.printf("%f", (1.0f/deltat)); pc.printf(" Hz"); + + + blinkOn = ~blinkOn; + count = t.read_ms(); +} + while(1) { + myled = !myled; + wait(1); + } +}