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Dependencies:   mbed

Dependents:   fluy343

IMU/Sensors/Gyro_Acc/MPU6050.cpp@7:ac2895479e34, 2014-07-12 (annotated)

Committer:
maetugr
Date:
Sat Jul 12 12:21:11 2014 +0000
Revision:
7:ac2895479e34
Parent:
5:06e978fd147a
Child:
8:e79c7939d6de
A stable working Acro-mode :); some little oscillations to be solved and then the angle-mode draft will get used

Who changed what in which revision?

UserRevisionLine numberNew contents of line
maetugr 4:b0a60b0b24a9 1 #include "MPU6050.h"
maetugr 4:b0a60b0b24a9 2
maetugr 4:b0a60b0b24a9 3 MPU6050::MPU6050(PinName sda, PinName scl) : I2C_Sensor(sda, scl, MPU6050_I2C_ADDRESS)
maetugr 4:b0a60b0b24a9 4 {
maetugr 4:b0a60b0b24a9 5 // Turns on the MPU6050's gyro and initializes it
maetugr 4:b0a60b0b24a9 6 // register datasheet: http://www.invensense.com/mems/gyro/documents/RM-MPU-6000A.pdf
maetugr 4:b0a60b0b24a9 7 writeRegister(MPU6050_RA_PWR_MGMT_1, 0x01); // wake up from sleep and chooses Gyro X-Axis as Clock source (stadard sleeping and with inacurate clock is 0x40)
maetugr 7:ac2895479e34 8 writeRegister(MPU6050_RA_CONFIG, 0x03);
maetugr 4:b0a60b0b24a9 9 writeRegister(MPU6050_RA_GYRO_CONFIG, 0x18); // scales gyros range to +-2000dps
maetugr 4:b0a60b0b24a9 10 writeRegister(MPU6050_RA_ACCEL_CONFIG, 0x00); // scales accelerometers range to +-2g
maetugr 4:b0a60b0b24a9 11 }
maetugr 4:b0a60b0b24a9 12
maetugr 4:b0a60b0b24a9 13 void MPU6050::read()
maetugr 4:b0a60b0b24a9 14 {
maetugr 4:b0a60b0b24a9 15 readraw_gyro(); // read raw measurement data
maetugr 4:b0a60b0b24a9 16 readraw_acc();
maetugr 4:b0a60b0b24a9 17
maetugr 4:b0a60b0b24a9 18 for (int i = 0; i < 3; i++)
maetugr 5:06e978fd147a 19 data_gyro[i] = (raw_gyro[i] - offset_gyro[i])*0.07; // subtract offset from calibration and multiply unit factor to get degree per second (datasheet s.10)
maetugr 4:b0a60b0b24a9 20
maetugr 4:b0a60b0b24a9 21 for (int i = 0; i < 3; i++)
maetugr 4:b0a60b0b24a9 22 data_acc[i] = raw_acc[i] - offset_acc[i]; // TODO: didn't care about units because IMU-algorithm just uses vector direction
maetugr 5:06e978fd147a 23
maetugr 5:06e978fd147a 24 // I have to swich coordinates on my board to match the ones of the other sensors (clear this part if you use the raw coordinates of the sensor)
maetugr 5:06e978fd147a 25 float tmp = 0;
maetugr 5:06e978fd147a 26 tmp = data_gyro[0];
maetugr 5:06e978fd147a 27 data_gyro[0] = data_gyro[1];
maetugr 5:06e978fd147a 28 data_gyro[1] = -tmp;
maetugr 5:06e978fd147a 29 data_gyro[2] = data_gyro[2];
maetugr 5:06e978fd147a 30 tmp = data_acc[0];
maetugr 5:06e978fd147a 31 data_acc[0] = data_acc[1];
maetugr 5:06e978fd147a 32 data_acc[1] = -tmp;
maetugr 5:06e978fd147a 33 data_acc[2] = data_acc[2];
maetugr 4:b0a60b0b24a9 34 }
maetugr 4:b0a60b0b24a9 35
maetugr 4:b0a60b0b24a9 36 int MPU6050::readTemp()
maetugr 4:b0a60b0b24a9 37 {
maetugr 4:b0a60b0b24a9 38 char buffer[2]; // 8-Bit pieces of temperature data
maetugr 4:b0a60b0b24a9 39
maetugr 4:b0a60b0b24a9 40 readMultiRegister(MPU6050_RA_TEMP_OUT_H, buffer, 2); // read the sensors register for the temperature
maetugr 4:b0a60b0b24a9 41 return (short) (buffer[0] << 8 | buffer[1]);
maetugr 4:b0a60b0b24a9 42 }
maetugr 4:b0a60b0b24a9 43
maetugr 4:b0a60b0b24a9 44 void MPU6050::readraw_gyro()
maetugr 4:b0a60b0b24a9 45 {
maetugr 4:b0a60b0b24a9 46 char buffer[6]; // 8-Bit pieces of axis data
maetugr 4:b0a60b0b24a9 47
maetugr 5:06e978fd147a 48 if(readMultiRegister(MPU6050_RA_GYRO_XOUT_H | (1 << 7), buffer, 6) != 0) return; // read axis registers using I2C // TODO: why?! | (1 << 7)
maetugr 4:b0a60b0b24a9 49
maetugr 4:b0a60b0b24a9 50 raw_gyro[0] = (short) (buffer[0] << 8 | buffer[1]); // join 8-Bit pieces to 16-bit short integers
maetugr 4:b0a60b0b24a9 51 raw_gyro[1] = (short) (buffer[2] << 8 | buffer[3]);
maetugr 4:b0a60b0b24a9 52 raw_gyro[2] = (short) (buffer[4] << 8 | buffer[5]);
maetugr 4:b0a60b0b24a9 53 }
maetugr 4:b0a60b0b24a9 54
maetugr 4:b0a60b0b24a9 55 void MPU6050::readraw_acc()
maetugr 4:b0a60b0b24a9 56 {
maetugr 4:b0a60b0b24a9 57 char buffer[6]; // 8-Bit pieces of axis data
maetugr 4:b0a60b0b24a9 58
maetugr 4:b0a60b0b24a9 59 readMultiRegister(MPU6050_RA_ACCEL_XOUT_H | (1 << 7), buffer, 6); // read axis registers using I2C // TODO: why?! | (1 << 7)
maetugr 4:b0a60b0b24a9 60
maetugr 4:b0a60b0b24a9 61 raw_acc[0] = (short) (buffer[0] << 8 | buffer[1]); // join 8-Bit pieces to 16-bit short integers
maetugr 4:b0a60b0b24a9 62 raw_acc[1] = (short) (buffer[2] << 8 | buffer[3]);
maetugr 4:b0a60b0b24a9 63 raw_acc[2] = (short) (buffer[4] << 8 | buffer[5]);
maetugr 4:b0a60b0b24a9 64 }
maetugr 4:b0a60b0b24a9 65
maetugr 4:b0a60b0b24a9 66 void MPU6050::calibrate(int times, float separation_time)
maetugr 4:b0a60b0b24a9 67 {
maetugr 4:b0a60b0b24a9 68 // calibrate sensor with an average of count samples (result of calibration stored in offset[])
maetugr 4:b0a60b0b24a9 69 // Calibrate Gyroscope ----------------------------------
maetugr 4:b0a60b0b24a9 70 float calib_gyro[3] = {0,0,0}; // temporary array for the sum of calibration measurement
maetugr 4:b0a60b0b24a9 71
maetugr 4:b0a60b0b24a9 72 for (int i = 0; i < times; i++) { // read 'times' times the data in a very short time
maetugr 4:b0a60b0b24a9 73 readraw_gyro();
maetugr 4:b0a60b0b24a9 74 for (int j = 0; j < 3; j++)
maetugr 4:b0a60b0b24a9 75 calib_gyro[j] += raw_gyro[j];
maetugr 4:b0a60b0b24a9 76 wait(separation_time);
maetugr 4:b0a60b0b24a9 77 }
maetugr 4:b0a60b0b24a9 78
maetugr 4:b0a60b0b24a9 79 for (int i = 0; i < 3; i++)
maetugr 4:b0a60b0b24a9 80 offset_gyro[i] = calib_gyro[i]/times; // take the average of the calibration measurements
maetugr 4:b0a60b0b24a9 81
maetugr 4:b0a60b0b24a9 82 // Calibrate Accelerometer -------------------------------
maetugr 4:b0a60b0b24a9 83 float calib_acc[3] = {0,0,0}; // temporary array for the sum of calibration measurement
maetugr 4:b0a60b0b24a9 84
maetugr 4:b0a60b0b24a9 85 for (int i = 0; i < times; i++) { // read 'times' times the data in a very short time
maetugr 4:b0a60b0b24a9 86 readraw_acc();
maetugr 4:b0a60b0b24a9 87 for (int j = 0; j < 3; j++)
maetugr 4:b0a60b0b24a9 88 calib_acc[j] += raw_acc[j];
maetugr 4:b0a60b0b24a9 89 wait(separation_time);
maetugr 4:b0a60b0b24a9 90 }
maetugr 4:b0a60b0b24a9 91
maetugr 4:b0a60b0b24a9 92 for (int i = 0; i < 2; i++)
maetugr 4:b0a60b0b24a9 93 offset_acc[i] = calib_acc[i]/times; // take the average of the calibration measurements
maetugr 4:b0a60b0b24a9 94 }