Akira Heya
Comparison with attitude estimation filter IMU : MPU9250
Revision 3:dc4292a7c440, committed 2019-01-14
- Comitter:
- AkiraHeya
- Date:
- Mon Jan 14 18:58:46 2019 +0000
- Parent:
- 2:4e59a37182df
- Commit message:
- Comparison with the attitude estimation filter
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/EKF.h Mon Jan 14 18:58:46 2019 +0000
@@ -0,0 +1,115 @@
+//------------------------------------------------------------------------------
+// Extended Kalman Filter for a sensor fusion (Gyroscope and accelataion sensor)
+//------------------------------------------------------------------------------
+#ifndef EKF_H
+#define EKF_H
+
+#include "mbed.h"
+#include "math.h"
+#include "Eigen/Core.h"
+#include "Eigen/Geometry.h"
+using namespace Eigen;
+
+//----Variables
+float wx, wy, wz;
+float s_pre_a, s_pre_b, c_pre_a, c_pre_b;
+float preEst_a, preEst_b;
+float s2_pre_a, c2_pre_a;
+float af1_a, af1_b, af2_a, af2_b;
+float pre_a = 0.0;
+float pre_b = 0.0;
+float estAlpha, estBeta;
+float b = 1.0f;
+//--For check
+float xhat0, xhat1;
+float af00, af01, af10, af11;
+float P00, P01, P10, P11;
+float KG00, KG01, KG10, KG11;
+float eye00, eye01, eye10, eye11;
+
+//----Vector
+Vector2f y;
+Vector2f h;
+Vector2f xhat;
+Vector2f xhat_new;
+
+//----Matrix
+Matrix2f eye = Matrix2f::Identity();
+Matrix2f af;
+Matrix2f ah = eye;
+Matrix2f P = 1*eye;
+Matrix2f pre_P = 1*eye;
+Matrix2f P_new;
+Matrix2f KG_den; // denominator of kalman gain
+Matrix2f KalmanGain;
+Matrix2f Q = 0.001*eye; // Covariance matrix
+Matrix2f R = 0.001*eye;
+
+class EKF
+{
+ protected:
+
+ public:
+ void ExtendedKalmanFilterUpdate(float th_ax, float th_ay, float pre_wx, float pre_wy, float pre_wz)
+ {
+ //----Prediction step
+ //--Previous estimated state
+ s_pre_a = sin(pre_a);
+ c_pre_a = cos(pre_a);
+ s_pre_b = sin(pre_b);
+ c_pre_b = cos(pre_b);
+
+ // PreEst alpha, beta
+ xhat(0) = pre_a + delt_t*(pre_wx*(c_pre_a*c_pre_a*c_pre_b + s_pre_a*s_pre_a*s_pre_b) + pre_wy*(s_pre_a*s_pre_b) - pre_wz*(c_pre_a*c_pre_b));
+ xhat0 = xhat(0);
+ xhat(1) = pre_b + delt_t*(pre_wy*c_pre_a*c_pre_b + pre_wz*s_pre_a*s_pre_b);
+ xhat1 = xhat(1);
+
+ //--Linearized system
+ s2_pre_a = sin(2.0f*pre_a);
+ c2_pre_a = cos(2.0f*pre_a);
+ // af1_a, af1_b, af2_a, af2_b
+ af(0,0) = 1.0f + delt_t*(pre_wx*(-s2_pre_a*c_pre_b + s2_pre_a*s_pre_b) + pre_wy*c_pre_a*s_pre_b);
+ af(0,1) = delt_t*(-pre_wx*(c_pre_a*c_pre_a*s_pre_b + s_pre_b*s_pre_a*c_pre_b) + pre_wy*s_pre_a*c_pre_b);
+ af(1,0) = delt_t*(-pre_wy*s_pre_a*c_pre_b + pre_wz*c_pre_a*s_pre_b);
+ af(1,1) = 1.0f + delt_t*(-pre_wy*(c_pre_a*s_pre_b) + pre_wz*(s_pre_a*c_pre_b));
+
+ //--Previous error covariance matrix
+ P = af*pre_P*af.transpose() + b*Q*b;
+
+ //----Filtering step
+ //--Kalman gain calulation
+ KG_den = ah.transpose()*P*ah + R;
+ KalmanGain = (P*ah)*KG_den.inverse();
+
+ /*
+ KG00 = KalmanGain(0,0);
+ KG01 = KalmanGain(0,1);
+ KG10 = KalmanGain(1,0);
+ KG11 = KalmanGain(1,1);
+ */
+
+ //--New Estimated state
+ h(0) = xhat0;
+ h(1) = xhat1;
+ y(0) = th_ax;
+ y(1) = th_ay;
+ xhat_new = xhat + KalmanGain*(y - h);
+ estAlpha = xhat_new(0);
+ estBeta = xhat_new(1);
+
+ //--New covariance matrix
+ P_new = (eye - KalmanGain*ah.transpose())*P;
+
+ //--Set the current value as previous value
+ pre_wx = wx;
+ pre_wy = wy;
+ pre_wz = wz;
+ pre_th_ax = th_ax;
+ pre_th_ay = th_ay;
+ pre_P = P_new;
+ pre_a = estAlpha;
+ pre_b = estBeta;
+ }
+};
+#endif
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Eigen.lib Mon Jan 14 18:58:46 2019 +0000 @@ -0,0 +1,1 @@ +https://os.mbed.com/users/ykuroda/code/Eigen/#13a5d365ba16
--- a/MPU9250.h Tue Aug 05 01:37:23 2014 +0000
+++ b/MPU9250.h Mon Jan 14 18:58:46 2019 +0000
@@ -1,12 +1,12 @@
+//------------------------------------------------------------------------------
+// Attitude measurement using IMU(MPU-9250)
+//------------------------------------------------------------------------------
#ifndef MPU9250_H
#define MPU9250_H
-
+
#include "mbed.h"
#include "math.h"
-
-// See also MPU-9250 Register Map and Descriptions, Revision 4.0, RM-MPU-9250A-00, Rev. 1.4, 9/9/2013 for registers not listed in
-// above document; the MPU9250 and MPU9150 are virtually identical but the latter has a different register map
-//
+
//Magnetometer Registers
#define AK8963_ADDRESS 0x0C<<1
#define WHO_AM_I_AK8963 0x00 // should return 0x48
@@ -26,11 +26,12 @@
#define AK8963_ASAY 0x11 // Fuse ROM y-axis sensitivity adjustment value
#define AK8963_ASAZ 0x12 // Fuse ROM z-axis sensitivity adjustment value
-#define SELF_TEST_X_GYRO 0x00
-#define SELF_TEST_Y_GYRO 0x01
+#define SELF_TEST_X_GYRO 0x00
+#define SELF_TEST_Y_GYRO 0x01
#define SELF_TEST_Z_GYRO 0x02
-/*#define X_FINE_GAIN 0x03 // [7:0] fine gain
+/*
+#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
@@ -38,10 +39,11 @@
#define YA_OFFSET_H 0x08
#define YA_OFFSET_L_TC 0x09
#define ZA_OFFSET_H 0x0A
-#define ZA_OFFSET_L_TC 0x0B */
+#define ZA_OFFSET_L_TC 0x0B
+*/
#define SELF_TEST_X_ACCEL 0x0D
-#define SELF_TEST_Y_ACCEL 0x0E
+#define SELF_TEST_Y_ACCEL 0x0E
#define SELF_TEST_Z_ACCEL 0x0F
#define SELF_TEST_A 0x10
@@ -57,15 +59,15 @@
#define GYRO_CONFIG 0x1B
#define ACCEL_CONFIG 0x1C
#define ACCEL_CONFIG2 0x1D
-#define LP_ACCEL_ODR 0x1E
-#define WOM_THR 0x1F
+#define LP_ACCEL_ODR 0x1E
+#define WOM_THR 0x1F
#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_MST_CTRL 0x24
#define I2C_SLV0_ADDR 0x25
#define I2C_SLV0_REG 0x26
#define I2C_SLV0_CTRL 0x27
@@ -141,7 +143,7 @@
#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 DMP_REG_2 0x71
#define FIFO_COUNTH 0x72
#define FIFO_COUNTL 0x73
#define FIFO_R_W 0x74
@@ -153,7 +155,6 @@
#define ZA_OFFSET_H 0x7D
#define ZA_OFFSET_L 0x7E
-// Using the MSENSR-9250 breakout board, ADO is set to 0
// Seven-bit device address is 110100 for ADO = 0 and 110101 for ADO = 1
//mbed uses the eight-bit device address, so shift seven-bit addresses left by one!
#define ADO 0
@@ -161,7 +162,7 @@
#define MPU9250_ADDRESS 0x69<<1 // Device address when ADO = 1
#else
#define MPU9250_ADDRESS 0x68<<1 // Device address when ADO = 0
-#endif
+#endif
// Set initial input parameters
enum Ascale {
@@ -186,29 +187,32 @@
uint8_t Ascale = AFS_2G; // AFS_2G, AFS_4G, AFS_8G, AFS_16G
uint8_t Gscale = GFS_250DPS; // GFS_250DPS, GFS_500DPS, GFS_1000DPS, GFS_2000DPS
uint8_t Mscale = MFS_16BITS; // MFS_14BITS or MFS_16BITS, 14-bit or 16-bit magnetometer resolution
-uint8_t Mmode = 0x06; // Either 8 Hz 0x02) or 100 Hz (0x06) magnetometer data ODR
+uint8_t Mmode = 0x06; // Either 8 Hz 0x02) or 100 Hz (0x06) magnetometer data ODR
float aRes, gRes, mRes; // scale resolutions per LSB for the sensors
//Set up I2C, (SDA,SCL)
-I2C i2c(I2C_SDA, I2C_SCL);
+I2C i2c(p9, p10);
-DigitalOut myled(LED1);
-
// 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
int16_t gyroCount[3]; // Stores the 16-bit signed gyro sensor output
int16_t magCount[3]; // Stores the 16-bit signed magnetometer sensor output
float magCalibration[3] = {0, 0, 0}, magbias[3] = {0, 0, 0}; // Factory mag calibration and mag bias
float gyroBias[3] = {0, 0, 0}, accelBias[3] = {0, 0, 0}; // Bias corrections for gyro and accelerometer
-float ax, ay, az, gx, gy, gz, mx, my, mz; // variables to hold latest sensor data values
+float ax, ay, az, gx, gy, gz, mx, my, mz; // variables to hold latest sensor data values
+float th_ax, th_ay, th_az;
+float th_ax_LPF, th_ay_LPF, th_az_LPF;
+float pre_th_ax, pre_th_ay, pre_th_az;
+float th_gx, th_gy, th_gz;
+float pre_gx, pre_gy, pre_gz;
+float th_x, th_y, th_z, th_x_d, th_y_d, th_z_d;
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
+float delt_t = 0.0f; // used to display output rate
+float sum_dt = 0.0f; //
+float dt0_ekf, dt1_ekf, dt0_mwf, dt1_mwf;
// parameters for 6 DoF sensor fusion calculations
float PI = 3.14159265358979323846f;
@@ -220,15 +224,19 @@
#define Ki 0.0f
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 pre_pitch, pre_roll;
+float lastUpdate = 0.0f, firstUpdate = 0.0f, Now = 0.0f; // 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
+float q1 = 1.0f;
+float q2 = 0.0f;
+float q3 = 0.0f;
+float q4 = 0.0f;
float eInt[3] = {0.0f, 0.0f, 0.0f}; // vector to hold integral error for Mahony method
class MPU9250 {
-
+
protected:
-
+
public:
//===================================================================================================================
//====== Set of useful function to access acceleratio, gyroscope, and temperature data
@@ -244,26 +252,25 @@
char readByte(uint8_t address, uint8_t subAddress)
{
- char data[1]; // `data` will store the register data
+ 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];
+ 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);
+ i2c.read(address, data, count, 0);
for(int ii = 0; ii < count; ii++) {
dest[ii] = data[ii];
}
-}
-
+}
void getMres() {
switch (Mscale)
@@ -279,12 +286,11 @@
}
}
-
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).
+ // 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;
@@ -301,12 +307,11 @@
}
}
-
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).
+ // 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;
@@ -329,8 +334,8 @@
uint8_t rawData[6]; // x/y/z accel register data stored here
readBytes(MPU9250_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]) ;
+ 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)
@@ -338,8 +343,8 @@
uint8_t rawData[6]; // x/y/z gyro register data stored here
readBytes(MPU9250_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]) ;
+ destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
+ destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
}
void readMagData(int16_t * destination)
@@ -348,41 +353,43 @@
if(readByte(AK8963_ADDRESS, AK8963_ST1) & 0x01) { // wait for magnetometer data ready bit to be set
readBytes(AK8963_ADDRESS, AK8963_XOUT_L, 7, &rawData[0]); // Read the six raw data and ST2 registers sequentially into data array
uint8_t c = rawData[6]; // End data read by reading ST2 register
- if(!(c & 0x08)) { // Check if magnetic sensor overflow set, if not then report data
+ if(!(c & 0x08))
+ { // Check if magnetic sensor overflow set, if not then report data
destination[0] = (int16_t)(((int16_t)rawData[1] << 8) | rawData[0]); // Turn the MSB and LSB into a signed 16-bit value
destination[1] = (int16_t)(((int16_t)rawData[3] << 8) | rawData[2]) ; // Data stored as little Endian
- destination[2] = (int16_t)(((int16_t)rawData[5] << 8) | rawData[4]) ;
- }
+ destination[2] = (int16_t)(((int16_t)rawData[5] << 8) | rawData[4]) ;
+ }
}
}
int16_t readTempData()
{
uint8_t rawData[2]; // x/y/z gyro register data stored here
- readBytes(MPU9250_ADDRESS, TEMP_OUT_H, 2, &rawData[0]); // Read the two raw data registers sequentially into data array
+ readBytes(MPU9250_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
}
-void resetMPU9250() {
+void resetMPU9250()
+{
// reset device
writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
wait(0.1);
- }
-
+}
+
void initAK8963(float * destination)
{
// First extract the factory calibration for each magnetometer axis
uint8_t rawData[3]; // x/y/z gyro calibration data stored here
- writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
+ writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
wait(0.01);
writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x0F); // Enter Fuse ROM access mode
wait(0.01);
readBytes(AK8963_ADDRESS, AK8963_ASAX, 3, &rawData[0]); // Read the x-, y-, and z-axis calibration values
destination[0] = (float)(rawData[0] - 128)/256.0f + 1.0f; // Return x-axis sensitivity adjustment values, etc.
- destination[1] = (float)(rawData[1] - 128)/256.0f + 1.0f;
- destination[2] = (float)(rawData[2] - 128)/256.0f + 1.0f;
- writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
+ destination[1] = (float)(rawData[1] - 128)/256.0f + 1.0f;
+ destination[2] = (float)(rawData[2] - 128)/256.0f + 1.0f;
+ writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
wait(0.01);
// Configure the magnetometer for continuous read and highest resolution
// set Mscale bit 4 to 1 (0) to enable 16 (14) bit resolution in CNTL register,
@@ -393,72 +400,72 @@
void initMPU9250()
-{
+{
// Initialize MPU9250 device
// wake up device
- writeByte(MPU9250_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
+ writeByte(MPU9250_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(MPU9250_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;
+ // 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(MPU9250_ADDRESS, CONFIG, 0x03);
-
+ writeByte(MPU9250_ADDRESS, CONFIG, 0x03);
+
// Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV)
writeByte(MPU9250_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(MPU9250_ADDRESS, GYRO_CONFIG);
- writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
+ writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c | Gscale << 3); // Set full scale range for the gyro
-
+
// Set accelerometer configuration
c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG);
- writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
+ writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
- writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c | Ascale << 3); // Set full scale range for the accelerometer
+ writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c | Ascale << 3); // Set full scale range for the accelerometer
// Set accelerometer sample rate configuration
// It is possible to get a 4 kHz sample rate from the accelerometer by choosing 1 for
// accel_fchoice_b bit [3]; in this case the bandwidth is 1.13 kHz
c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG2);
- writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c & ~0x0F); // Clear accel_fchoice_b (bit 3) and A_DLPFG (bits [2:0])
+ writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c & ~0x0F); // Clear accel_fchoice_b (bit 3) and A_DLPFG (bits [2:0])
writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c | 0x03); // Set accelerometer rate to 1 kHz and bandwidth to 41 Hz
- // The accelerometer, gyro, and thermometer are set to 1 kHz sample rates,
+ // The accelerometer, gyro, and thermometer are set to 1 kHz sample rates,
// but all these rates are further reduced by a factor of 5 to 200 Hz because of the SMPLRT_DIV setting
// 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
+ // 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(MPU9250_ADDRESS, INT_PIN_CFG, 0x22);
+ writeByte(MPU9250_ADDRESS, INT_PIN_CFG, 0x22);
writeByte(MPU9250_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 calibrateMPU9250(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(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
- wait(0.1);
-
+ wait(0.1);
+
// get stable time source
// Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
- writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01);
- writeByte(MPU9250_ADDRESS, PWR_MGMT_2, 0x00);
+ writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01);
+ writeByte(MPU9250_ADDRESS, PWR_MGMT_2, 0x00);
wait(0.2);
-
+
// Configure device for bias calculation
writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x00); // Disable all interrupts
writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable FIFO
@@ -467,18 +474,18 @@
writeByte(MPU9250_ADDRESS, USER_CTRL, 0x00); // Disable FIFO and I2C master modes
writeByte(MPU9250_ADDRESS, USER_CTRL, 0x0C); // Reset FIFO and DMP
wait(0.015);
-
+
// Configure MPU9250 gyro and accelerometer for bias calculation
writeByte(MPU9250_ADDRESS, CONFIG, 0x01); // Set low-pass filter to 188 Hz
writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz
writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity
writeByte(MPU9250_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(MPU9250_ADDRESS, USER_CTRL, 0x40); // Enable FIFO
+ writeByte(MPU9250_ADDRESS, USER_CTRL, 0x40); // Enable FIFO
writeByte(MPU9250_ADDRESS, FIFO_EN, 0x78); // Enable gyro and accelerometer sensors for FIFO (max size 512 bytes in MPU-9250)
wait(0.04); // accumulate 40 samples in 80 milliseconds = 480 bytes
@@ -488,41 +495,42 @@
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++) {
+ for (ii = 0; ii < packet_count; ii++)
+ {
int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0};
readBytes(MPU9250_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] ) ;
+ 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;
+
+ 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(MPU9250_ADDRESS, XG_OFFSET_H, data[0]);
@@ -532,9 +540,9 @@
writeByte(MPU9250_ADDRESS, ZG_OFFSET_H, data[4]);
writeByte(MPU9250_ADDRESS, ZG_OFFSET_L, 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;
+ 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
@@ -542,35 +550,36 @@
// 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(MPU9250_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(MPU9250_ADDRESS, YA_OFFSET_H, 2, &data[0]);
- accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1];
- readBytes(MPU9250_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
- }
+ int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases
+ readBytes(MPU9250_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(MPU9250_ADDRESS, YA_OFFSET_H, 2, &data[0]);
+ accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1];
+ readBytes(MPU9250_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
- // 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
+ 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
// Apparently this is not working for the acceleration biases in the MPU-9250
// Are we handling the temperature correction bit properly?
@@ -582,204 +591,180 @@
writeByte(MPU9250_ADDRESS, ZA_OFFSET_H, data[4]);
writeByte(MPU9250_ADDRESS, ZA_OFFSET_L, 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;
-}
+ // 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 MPU9250SelfTest(float * destination) // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass
-{
- uint8_t rawData[6] = {0, 0, 0, 0, 0, 0};
- uint8_t selfTest[6];
- int16_t gAvg[3], aAvg[3], aSTAvg[3], gSTAvg[3];
- float factoryTrim[6];
- uint8_t FS = 0;
-
- writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set gyro sample rate to 1 kHz
- writeByte(MPU9250_ADDRESS, CONFIG, 0x02); // Set gyro sample rate to 1 kHz and DLPF to 92 Hz
- writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 1<<FS); // Set full scale range for the gyro to 250 dps
- writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, 0x02); // Set accelerometer rate to 1 kHz and bandwidth to 92 Hz
- writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 1<<FS); // Set full scale range for the accelerometer to 2 g
+ // Accelerometer and gyroscope self test; check calibration wrt factory settings
+ void MPU9250SelfTest(float * destination) // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass
+ {
+ uint8_t rawData[6] = {0, 0, 0, 0, 0, 0};
+ uint8_t selfTest[6];
+ int16_t gAvg[3], aAvg[3], aSTAvg[3], gSTAvg[3];
+ float factoryTrim[6];
+ uint8_t FS = 0;
+
+ writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set gyro sample rate to 1 kHz
+ writeByte(MPU9250_ADDRESS, CONFIG, 0x02); // Set gyro sample rate to 1 kHz and DLPF to 92 Hz
+ writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 1<<FS); // Set full scale range for the gyro to 250 dps
+ writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, 0x02); // Set accelerometer rate to 1 kHz and bandwidth to 92 Hz
+ writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 1<<FS); // Set full scale range for the accelerometer to 2 g
+
+ for( int ii = 0; ii < 200; ii++) { // get average current values of gyro and acclerometer
+
+ readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
+ aAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
+ aAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
+ aAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
+
+ readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
+ gAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
+ gAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
+ gAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
+ }
+
+ for (int ii =0; ii < 3; ii++)
+ {
+ // Get average of 200 values and store as average current readings
+ aAvg[ii] /= 200;
+ gAvg[ii] /= 200;
+ }
- for( int ii = 0; ii < 200; ii++) { // get average current values of gyro and acclerometer
-
- readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
- aAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
- aAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
- aAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
-
+ // Configure the accelerometer for self-test
+ writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g
+ writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s
+ //delay(25); // Delay a while to let the device stabilize
+
+ for( int ii = 0; ii < 200; ii++)
+ {
+ // get average self-test values of gyro and acclerometer
+ readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
+ aSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
+ aSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
+ aSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
+
readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
- gAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
- gAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
- gAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
- }
-
- for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average current readings
- aAvg[ii] /= 200;
- gAvg[ii] /= 200;
- }
-
-// Configure the accelerometer for self-test
- writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g
- writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s
- delay(25); // Delay a while to let the device stabilize
+ gSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
+ gSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
+ gSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
+ }
+
+ for (int ii =0; ii < 3; ii++)
+ {
+ // Get average of 200 values and store as average self-test readings
+ aSTAvg[ii] /= 200;
+ gSTAvg[ii] /= 200;
+ }
+
+ // Configure the gyro and accelerometer for normal operation
+ writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00);
+ writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00);
+ //delay(25); // Delay a while to let the device stabilize
+
+ // Retrieve accelerometer and gyro factory Self-Test Code from USR_Reg
+ selfTest[0] = readByte(MPU9250_ADDRESS, SELF_TEST_X_ACCEL); // X-axis accel self-test results
+ selfTest[1] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_ACCEL); // Y-axis accel self-test results
+ selfTest[2] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_ACCEL); // Z-axis accel self-test results
+ selfTest[3] = readByte(MPU9250_ADDRESS, SELF_TEST_X_GYRO); // X-axis gyro self-test results
+ selfTest[4] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_GYRO); // Y-axis gyro self-test results
+ selfTest[5] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_GYRO); // Z-axis gyro self-test results
- for( int ii = 0; ii < 200; ii++) { // get average self-test values of gyro and acclerometer
-
- readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
- aSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
- aSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
- aSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
-
- readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
- gSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
- gSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
- gSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
- }
-
- for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average self-test readings
- aSTAvg[ii] /= 200;
- gSTAvg[ii] /= 200;
+ // Retrieve factory self-test value from self-test code reads
+ factoryTrim[0] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[0] - 1.0) )); // FT[Xa] factory trim calculation
+ factoryTrim[1] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[1] - 1.0) )); // FT[Ya] factory trim calculation
+ factoryTrim[2] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[2] - 1.0) )); // FT[Za] factory trim calculation
+ factoryTrim[3] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[3] - 1.0) )); // FT[Xg] factory trim calculation
+ factoryTrim[4] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[4] - 1.0) )); // FT[Yg] factory trim calculation
+ factoryTrim[5] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[5] - 1.0) )); // FT[Zg] factory trim calculation
+
+ // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response
+ // To get percent, must multiply by 100
+ for (int i = 0; i < 3; i++)
+ {
+ destination[i] = 100.0*((float)(aSTAvg[i] - aAvg[i]))/factoryTrim[i]; // Report percent differences
+ destination[i+3] = 100.0*((float)(gSTAvg[i] - gAvg[i]))/factoryTrim[i+3]; // Report percent differences
+ }
+
}
-
- // Configure the gyro and accelerometer for normal operation
- writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00);
- writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00);
- delay(25); // Delay a while to let the device stabilize
-
- // Retrieve accelerometer and gyro factory Self-Test Code from USR_Reg
- selfTest[0] = readByte(MPU9250_ADDRESS, SELF_TEST_X_ACCEL); // X-axis accel self-test results
- selfTest[1] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_ACCEL); // Y-axis accel self-test results
- selfTest[2] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_ACCEL); // Z-axis accel self-test results
- selfTest[3] = readByte(MPU9250_ADDRESS, SELF_TEST_X_GYRO); // X-axis gyro self-test results
- selfTest[4] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_GYRO); // Y-axis gyro self-test results
- selfTest[5] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_GYRO); // Z-axis gyro self-test results
+
+ void MadgwickFilterUpdate_6axis(float ax, float ay, float az, float wx, float wy, float wz)
+ {
+ // Local system variables
+ float norm; // vector norm
+ float SEqDot_omega_1, SEqDot_omega_2, SEqDot_omega_3, SEqDot_omega_4; // quaternion derrivative from gyroscopes elements
+ float f_1, f_2, f_3; // objective function elements
+ float J_11or24, J_12or23, J_13or22, J_14or21, J_32, J_33; // objective function Jacobian elements
+ float SEqHatDot_1, SEqHatDot_2, SEqHatDot_3, SEqHatDot_4; // estimated direction of the gyroscope error
+
+ // Axulirary variables to avoid reapeated calcualtions
+ float halfSEq_1 = 0.5f * q1;
+ float halfSEq_2 = 0.5f * q2;
+ float halfSEq_3 = 0.5f * q3;
+ float halfSEq_4 = 0.5f * q4;
+ float twoSEq_1 = 2.0f * q1;
+ float twoSEq_2 = 2.0f * q2;
+ float twoSEq_3 = 2.0f * q3;
+
+ // Normalise the accelerometer measurement
+ norm = sqrt(ax * ax + ay * ay + az * az);
+ ax /= norm;
+ ay /= norm;
+ az /= norm;
- // Retrieve factory self-test value from self-test code reads
- factoryTrim[0] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[0] - 1.0) )); // FT[Xa] factory trim calculation
- factoryTrim[1] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[1] - 1.0) )); // FT[Ya] factory trim calculation
- factoryTrim[2] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[2] - 1.0) )); // FT[Za] factory trim calculation
- factoryTrim[3] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[3] - 1.0) )); // FT[Xg] factory trim calculation
- factoryTrim[4] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[4] - 1.0) )); // FT[Yg] factory trim calculation
- factoryTrim[5] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[5] - 1.0) )); // FT[Zg] factory trim calculation
-
- // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response
- // To get percent, must multiply by 100
- for (int i = 0; i < 3; i++) {
- destination[i] = 100.0*((float)(aSTAvg[i] - aAvg[i]))/factoryTrim[i]; // Report percent differences
- destination[i+3] = 100.0*((float)(gSTAvg[i] - gAvg[i]))/factoryTrim[i+3]; // Report percent differences
- }
-
-}
+ // Compute the objective function and Jacobian
+ f_1 = twoSEq_2 * q4 - twoSEq_1 * q3 - ax;
+ f_2 = twoSEq_1 * q2 + twoSEq_3 * q4 - ay;
+ f_3 = 1.0f - twoSEq_2 * q2 - twoSEq_3 * q3 - az;
+ J_11or24 = twoSEq_3; // J_11 negated in matrix multiplication
+ J_12or23 = 2.0f * q4;
+ J_13or22 = twoSEq_1; // J_12 negated in matrix multiplication
+ J_14or21 = twoSEq_2;
+ J_32 = 2.0f * J_14or21; // negated in matrix multiplication
+ J_33 = 2.0f * J_11or24; // negated in matrix multiplication
+
+ // Compute the gradient (matrix multiplication)
+ SEqHatDot_1 = J_14or21 * f_2 - J_11or24 * f_1;
+ SEqHatDot_2 = J_12or23 * f_1 + J_13or22 * f_2 - J_32 * f_3;
+ SEqHatDot_3 = J_12or23 * f_2 - J_33 * f_3 - J_13or22 * f_1;
+ SEqHatDot_4 = J_14or21 * f_1 + J_11or24 * f_2;
+
+ // Normalise the gradient
+ norm = sqrt(SEqHatDot_1 * SEqHatDot_1 + SEqHatDot_2 * SEqHatDot_2 + SEqHatDot_3 * SEqHatDot_3 + SEqHatDot_4 * SEqHatDot_4);
+ SEqHatDot_1 /= norm;
+ SEqHatDot_2 /= norm;
+ SEqHatDot_3 /= norm;
+ SEqHatDot_4 /= norm;
+
+ // Compute the quaternion derrivative measured by gyroscopes
+ SEqDot_omega_1 = -halfSEq_2 * wx - halfSEq_3 * wy - halfSEq_4 * wz;
+ SEqDot_omega_2 = halfSEq_1 * wx + halfSEq_3 * wz - halfSEq_4 * wy;
+ SEqDot_omega_3 = halfSEq_1 * wy - halfSEq_2 * wz + halfSEq_4 * wx;
+ SEqDot_omega_4 = halfSEq_1 * wz + halfSEq_2 * wy - halfSEq_3 * wx;
+
+ // Compute then integrate the estimated quaternion derrivative
+ q1 += (SEqDot_omega_1 - (beta * SEqHatDot_1)) * delt_t;
+ q2 += (SEqDot_omega_2 - (beta * SEqHatDot_2)) * delt_t;
+ q3 += (SEqDot_omega_3 - (beta * SEqHatDot_3)) * delt_t;
+ q4 += (SEqDot_omega_4 - (beta * SEqHatDot_4)) * delt_t;
+
+ // Normalise quaternion
+ norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4);
+ q1 /= norm;
+ q2 /= norm;
+ q3 /= norm;
+ q4 /= norm;
+
+ }
-// 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, rotation rate, and magnetic moments to produce a quaternion-based estimate of absolute
-// 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 mx, float my, float mz)
- {
- float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
- float norm;
- float hx, hy, _2bx, _2bz;
- float s1, s2, s3, s4;
- float qDot1, qDot2, qDot3, qDot4;
-
- // Auxiliary variables to avoid repeated arithmetic
- float _2q1mx;
- float _2q1my;
- float _2q1mz;
- float _2q2mx;
- float _4bx;
- float _4bz;
- 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;
- float q1q1 = q1 * q1;
- float q1q2 = q1 * q2;
- float q1q3 = q1 * q3;
- float q1q4 = q1 * q4;
- float q2q2 = q2 * q2;
- float q2q3 = q2 * q3;
- float q2q4 = q2 * q4;
- float q3q3 = q3 * q3;
- float q3q4 = q3 * q4;
- float q4q4 = q4 * 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;
-
- // Normalise magnetometer measurement
- norm = sqrt(mx * mx + my * my + mz * mz);
- if (norm == 0.0f) return; // handle NaN
- norm = 1.0f/norm;
- mx *= norm;
- my *= norm;
- mz *= norm;
-
- // Reference direction of Earth's magnetic field
- _2q1mx = 2.0f * q1 * mx;
- _2q1my = 2.0f * q1 * my;
- _2q1mz = 2.0f * q1 * mz;
- _2q2mx = 2.0f * q2 * mx;
- hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4;
- hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4;
- _2bx = sqrt(hx * hx + hy * hy);
- _2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4;
- _4bx = 2.0f * _2bx;
- _4bz = 2.0f * _2bz;
-
- // Gradient decent algorithm corrective step
- s1 = -_2q3 * (2.0f * q2q4 - _2q1q3 - ax) + _2q2 * (2.0f * q1q2 + _2q3q4 - ay) - _2bz * q3 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q4 + _2bz * q2) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q3 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
- s2 = _2q4 * (2.0f * q2q4 - _2q1q3 - ax) + _2q1 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q2 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + _2bz * q4 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q3 + _2bz * q1) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q4 - _4bz * q2) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
- s3 = -_2q1 * (2.0f * q2q4 - _2q1q3 - ax) + _2q4 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q3 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + (-_4bx * q3 - _2bz * q1) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q2 + _2bz * q4) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q1 - _4bz * q3) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
- s4 = _2q2 * (2.0f * q2q4 - _2q1q3 - ax) + _2q3 * (2.0f * q1q2 + _2q3q4 - ay) + (-_4bx * q4 + _2bz * q2) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q1 + _2bz * q3) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q2 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
- norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4); // normalise step magnitude
- norm = 1.0f/norm;
- s1 *= norm;
- s2 *= norm;
- s3 *= norm;
- s4 *= norm;
-
- // Compute rate of change of quaternion
- qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1;
- qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2;
- qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3;
- qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4;
-
- // Integrate to yield quaternion
- q1 += qDot1 * deltat;
- q2 += qDot2 * deltat;
- q3 += qDot3 * deltat;
- q4 += qDot4 * deltat;
- 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;
-
- }
-
-
-
// Similar to Madgwick scheme but uses proportional and integral filtering on the error between estimated reference vectors and
- // measured ones.
- void MahonyQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz)
+ // measured ones.
+ /*
+ void MahonyQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz)
{
float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
float norm;
@@ -798,7 +783,7 @@
float q2q4 = q2 * q4;
float q3q3 = q3 * q3;
float q3q4 = q3 * q4;
- float q4q4 = q4 * q4;
+ float q4q4 = q4 * q4;
// Normalise accelerometer measurement
norm = sqrt(ax * ax + ay * ay + az * az);
@@ -828,7 +813,7 @@
vz = q1q1 - q2q2 - q3q3 + q4q4;
wx = 2.0f * bx * (0.5f - q3q3 - q4q4) + 2.0f * bz * (q2q4 - q1q3);
wy = 2.0f * bx * (q2q3 - q1q4) + 2.0f * bz * (q1q2 + q3q4);
- wz = 2.0f * bx * (q1q3 + q2q4) + 2.0f * bz * (0.5f - q2q2 - q3q3);
+ wz = 2.0f * bx * (q1q3 + q2q4) + 2.0f * bz * (0.5f - q2q2 - q3q3);
// Error is cross product between estimated direction and measured direction of gravity
ex = (ay * vz - az * vy) + (my * wz - mz * wy);
@@ -856,10 +841,10 @@
pa = q2;
pb = q3;
pc = q4;
- q1 = q1 + (-q2 * gx - q3 * gy - q4 * gz) * (0.5f * deltat);
- q2 = pa + (q1 * gx + pb * gz - pc * gy) * (0.5f * deltat);
- q3 = pb + (q1 * gy - pa * gz + pc * gx) * (0.5f * deltat);
- q4 = pc + (q1 * gz + pa * gy - pb * gx) * (0.5f * deltat);
+ q1 = q1 + (-q2 * gx - q3 * gy - q4 * gz) * (0.5f * delt_t);
+ q2 = pa + (q1 * gx + pb * gz - pc * gy) * (0.5f * delt_t);
+ q3 = pb + (q1 * gy - pa * gz + pc * gx) * (0.5f * delt_t);
+ q4 = pc + (q1 * gz + pa * gy - pb * gx) * (0.5f * delt_t);
// Normalise quaternion
norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4);
@@ -868,7 +853,8 @@
q[1] = q2 * norm;
q[2] = q3 * norm;
q[3] = q4 * norm;
-
+
}
+ */
};
-#endif
\ No newline at end of file
+#endif
--- a/N5110.lib Tue Aug 05 01:37:23 2014 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,1 +0,0 @@ -http://mbed.org/users/onehorse/code/Adfs/#28c629d0b0d0
--- a/ST_401_84MHZ.lib Tue Aug 05 01:37:23 2014 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,1 +0,0 @@ -http://mbed.org/users/dreschpe/code/ST_401_84MHZ/#b9343c8b85ec
--- a/main.cpp Tue Aug 05 01:37:23 2014 +0000
+++ b/main.cpp Mon Jan 14 18:58:46 2019 +0000
@@ -1,254 +1,148 @@
-/* MPU9250 Basic Example Code
- by: Kris Winer
- date: April 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 basic MPU-9250 functionality including parameterizing the register addresses, initializing the sensor,
- getting properly scaled accelerometer, gyroscope, and magnetometer data out. Added display functions to
- allow display to on breadboard monitor. Addition of 9 DoF sensor fusion using open source Madgwick and
- Mahony filter algorithms. Sketch runs on the 3.3 V 8 MHz Pro Mini and the Teensy 3.1.
-
- SDA and SCL should have external pull-up resistors (to 3.3V).
- 10k resistors are on the EMSENSR-9250 breakout board.
-
- Hardware setup:
- MPU9250 Breakout --------- Arduino
- VDD ---------------------- 3.3V
- VDDI --------------------- 3.3V
- SDA ----------------------- A4
- SCL ----------------------- A5
- GND ---------------------- GND
-
- Note: The MPU9250 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 "ST_F401_84MHZ.h"
-//F401_init84 myinit(0);
+//---------------------------------------------------------------------------
+// Attitude measurement using some attitude estimation filter
+// Filter : Complementary filter / Extended Kalman filter / Madgewick filter
+// IMU : MPU-9250
+// Written by Akira Heya
+// DATE : 2018/12/05
+//---------------------------------------------------------------------------
+
+//----include
#include "mbed.h"
#include "MPU9250.h"
-#include "N5110.h"
+#include "EKF.h"
+#include "math.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);
-
-float sum = 0;
-uint32_t sumCount = 0;
+//----variable
char buffer[14];
-
- MPU9250 mpu9250;
-
- Timer t;
+//----Instance
+MPU9250 mpu9250;
+EKF ekf;
+Timer t;
+Serial pc(USBTX, USBRX);
- Serial pc(USBTX, USBRX); // tx, rx
-
- // VCC, SCE, RST, D/C, MOSI,S CLK, LED
- N5110 lcd(PA_8, PB_10, PA_9, PA_6, PA_7, PA_5, PC_7);
-
-
-
+//****MAIN****
int main()
{
- pc.baud(9600);
-
- //Set up I2C
- i2c.frequency(400000); // use fast (400 kHz) I2C
-
- pc.printf("CPU SystemCoreClock is %d Hz\r\n", SystemCoreClock);
-
- t.start();
-
- lcd.init();
-// lcd.setBrightness(0.05);
-
-
+ //----Serial baud rate
+ pc.baud(921600);
+ //----I2C clock rate
+ i2c.frequency(400000);
+ //----System clock
+ //pc.printf("CPU SystemCoreClock is %d Hz\r\n", SystemCoreClock);
+ //----Timer start
+ t.start();
// Read the WHO_AM_I register, this is a good test of communication
- uint8_t whoami = mpu9250.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250); // Read WHO_AM_I register for MPU-9250
- pc.printf("I AM 0x%x\n\r", whoami); pc.printf("I SHOULD BE 0x71\n\r");
-
- if (whoami == 0x71) // WHO_AM_I should always be 0x68
- {
- pc.printf("MPU9250 WHO_AM_I is 0x%x\n\r", whoami);
- pc.printf("MPU9250 is online...\n\r");
- lcd.clear();
- lcd.printString("MPU9250 is", 0, 0);
- sprintf(buffer, "0x%x", whoami);
- lcd.printString(buffer, 0, 1);
- lcd.printString("shoud be 0x71", 0, 2);
- wait(1);
-
- mpu9250.resetMPU9250(); // Reset registers to default in preparation for device calibration
- mpu9250.MPU9250SelfTest(SelfTest); // Start by performing self test and reporting values
- pc.printf("x-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[0]);
- pc.printf("y-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[1]);
- pc.printf("z-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[2]);
- pc.printf("x-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[3]);
- pc.printf("y-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[4]);
- pc.printf("z-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[5]);
- mpu9250.calibrateMPU9250(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers
- pc.printf("x gyro bias = %f\n\r", gyroBias[0]);
- pc.printf("y gyro bias = %f\n\r", gyroBias[1]);
- pc.printf("z gyro bias = %f\n\r", gyroBias[2]);
- pc.printf("x accel bias = %f\n\r", accelBias[0]);
- pc.printf("y accel bias = %f\n\r", accelBias[1]);
- pc.printf("z accel bias = %f\n\r", accelBias[2]);
- wait(2);
- mpu9250.initMPU9250();
- pc.printf("MPU9250 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature
- mpu9250.initAK8963(magCalibration);
- pc.printf("AK8963 initialized for active data mode....\n\r"); // Initialize device for active mode read of magnetometer
- pc.printf("Accelerometer full-scale range = %f g\n\r", 2.0f*(float)(1<<Ascale));
- pc.printf("Gyroscope full-scale range = %f deg/s\n\r", 250.0f*(float)(1<<Gscale));
- if(Mscale == 0) pc.printf("Magnetometer resolution = 14 bits\n\r");
- if(Mscale == 1) pc.printf("Magnetometer resolution = 16 bits\n\r");
- if(Mmode == 2) pc.printf("Magnetometer ODR = 8 Hz\n\r");
- if(Mmode == 6) pc.printf("Magnetometer ODR = 100 Hz\n\r");
- wait(1);
- }
- else
- {
- pc.printf("Could not connect to MPU9250: \n\r");
- pc.printf("%#x \n", whoami);
-
- lcd.clear();
- lcd.printString("MPU9250", 0, 0);
- lcd.printString("no connection", 0, 1);
- sprintf(buffer, "WHO_AM_I 0x%x", whoami);
- lcd.printString(buffer, 0, 2);
-
- while(1) ; // Loop forever if communication doesn't happen
+ uint8_t whoami = mpu9250.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250);
+ pc.printf("I2C check : 0x%x\n\r", whoami);
+ //----Self check
+ if (whoami == 0x71)
+ {
+ pc.printf("MPU9250 is online\n\r");
+ sprintf(buffer, "0x%x", whoami);
+ wait(1);
+ //----Reset registers to default in preparation for device calibration
+ mpu9250.resetMPU9250();
+ //----Start by performing self test and reporting values
+ mpu9250.MPU9250SelfTest(SelfTest);
+ pc.printf("x-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[0]);
+ pc.printf("y-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[1]);
+ pc.printf("z-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[2]);
+ pc.printf("x-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[3]);
+ pc.printf("y-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[4]);
+ pc.printf("z-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[5]);
+ // Calibrate gyro and accelerometers, load biases in bias registers
+ mpu9250.calibrateMPU9250(gyroBias, accelBias);
+ pc.printf("x gyro bias = %f\n\r", gyroBias[0]);
+ pc.printf("y gyro bias = %f\n\r", gyroBias[1]);
+ pc.printf("z gyro bias = %f\n\r", gyroBias[2]);
+ pc.printf("x accel bias = %f\n\r", accelBias[0]);
+ pc.printf("y accel bias = %f\n\r", accelBias[1]);
+ pc.printf("z accel bias = %f\n\r", accelBias[2]);
+ wait(1);
+ //----Initialize device for active mode read of acclerometer, gyroscope, and temperature
+ mpu9250.initMPU9250();
+ pc.printf("MPU9250 initialized for active data mode....\n\r");
+ pc.printf("Accelerometer full-scale range = %f g\n\r", 2.0f*(float)(1<<Ascale));
+ pc.printf("Gyroscope full-scale range = %f deg/s\n\r", 250.0f*(float)(1<<Gscale));
+ wait(1);
}
-
- mpu9250.getAres(); // Get accelerometer sensitivity
- mpu9250.getGres(); // Get gyro sensitivity
- mpu9250.getMres(); // Get magnetometer sensitivity
+ else
+ {
+ pc.printf("Could not connect to MPU9250: \n\r");
+ pc.printf("%#x \n", whoami);
+ sprintf(buffer, "WHO_AM_I 0x%x", whoami);
+ //----Loop forever if communication doesn't happen
+ while(1) ;
+ }
+ //----Get accelerometer sensitivity
+ mpu9250.getAres();
+ //----Get gyro sensitivity
+ mpu9250.getGres();
pc.printf("Accelerometer sensitivity is %f LSB/g \n\r", 1.0f/aRes);
pc.printf("Gyroscope sensitivity is %f LSB/deg/s \n\r", 1.0f/gRes);
- pc.printf("Magnetometer sensitivity is %f LSB/G \n\r", 1.0f/mRes);
- magbias[0] = +470.; // User environmental x-axis correction in milliGauss, should be automatically calculated
- magbias[1] = +120.; // User environmental x-axis correction in milliGauss
- magbias[2] = +125.; // User environmental x-axis correction in milliGauss
-
- while(1) {
-
- // If intPin goes high, all data registers have new data
- if(mpu9250.readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01) { // On interrupt, check if data ready interrupt
+ wait(1);
+ //****LOOP****
+ while(1)
+ {
+ //----Time interval
+ Now = t.read_us();
+ delt_t = (Now - lastUpdate)/1000000.0f;
+ lastUpdate = Now;
+
+ //----Acceleration sensor
+ mpu9250.readAccelData(accelCount);
+ // 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];
+ th_ax = atan2(ay,sqrt(ax*ax+az*az))*(180.0f/PI);
+ th_ay = -1*atan2(ax,az)*(180.0f/PI);
- mpu9250.readAccelData(accelCount); // Read the x/y/z adc values
- // 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];
-
- mpu9250.readGyroData(gyroCount); // Read the x/y/z adc values
- // 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];
-
- mpu9250.readMagData(magCount); // Read the x/y/z adc values
- // Calculate the magnetometer values in milliGauss
- // Include factory calibration per data sheet and user environmental corrections
- mx = (float)magCount[0]*mRes*magCalibration[0] - magbias[0]; // get actual magnetometer value, this depends on scale being set
- my = (float)magCount[1]*mRes*magCalibration[1] - magbias[1];
- mz = (float)magCount[2]*mRes*magCalibration[2] - magbias[2];
- }
-
- Now = t.read_us();
- deltat = (float)((Now - lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update
- lastUpdate = Now;
-
- sum += deltat;
- sumCount++;
-
-// if(lastUpdate - firstUpdate > 10000000.0f) {
-// beta = 0.04; // decrease filter gain after stabilized
-// zeta = 0.015; // increasey bias drift gain after stabilized
- // }
-
- // Pass gyro rate as rad/s
-// mpu9250.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz);
- mpu9250.MahonyQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz);
+ //----Gyroscope
+ mpu9250.readGyroData(gyroCount);
+ // 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];
- // 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
-
- pc.printf("ax = %f", 1000*ax);
- pc.printf(" ay = %f", 1000*ay);
- pc.printf(" az = %f mg\n\r", 1000*az);
+ th_gx += (pre_gx + gx) * delt_t/2.0f;
+ th_gy += (pre_gy + gy) * delt_t/2.0f;
+ th_gz += (pre_gz + gz) * delt_t/2.0f;
+ pre_gx = gx;
+ pre_gy = gy;
+ pre_gz = gz;
- pc.printf("gx = %f", gx);
- pc.printf(" gy = %f", gy);
- pc.printf(" gz = %f deg/s\n\r", gz);
-
- pc.printf("gx = %f", mx);
- pc.printf(" gy = %f", my);
- pc.printf(" gz = %f mG\n\r", mz);
-
- tempCount = mpu9250.readTempData(); // Read the adc values
- temperature = ((float) tempCount) / 333.87f + 21.0f; // Temperature in degrees Centigrade
- pc.printf(" temperature = %f C\n\r", temperature);
-
- pc.printf("q0 = %f\n\r", q[0]);
- pc.printf("q1 = %f\n\r", q[1]);
- pc.printf("q2 = %f\n\r", q[2]);
- pc.printf("q3 = %f\n\r", q[3]);
-
-/* lcd.clear();
- lcd.printString("MPU9250", 0, 0);
- lcd.printString("x y z", 0, 1);
- sprintf(buffer, "%d %d %d mg", (int)(1000.0f*ax), (int)(1000.0f*ay), (int)(1000.0f*az));
- lcd.printString(buffer, 0, 2);
- sprintf(buffer, "%d %d %d deg/s", (int)gx, (int)gy, (int)gz);
- lcd.printString(buffer, 0, 3);
- sprintf(buffer, "%d %d %d mG", (int)mx, (int)my, (int)mz);
- lcd.printString(buffer, 0, 4);
- */
- // 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;
- yaw -= 13.8f; // Declination at Danville, California is 13 degrees 48 minutes and 47 seconds on 2014-04-04
- roll *= 180.0f / PI;
-
- pc.printf("Yaw, Pitch, Roll: %f %f %f\n\r", yaw, pitch, roll);
- pc.printf("average rate = %f\n\r", (float) sumCount/sum);
-// sprintf(buffer, "YPR: %f %f %f", yaw, pitch, roll);
-// lcd.printString(buffer, 0, 4);
-// sprintf(buffer, "rate = %f", (float) sumCount/sum);
-// lcd.printString(buffer, 0, 5);
-
- myled= !myled;
- count = t.read_ms();
-
- if(count > 1<<21) {
- t.start(); // start the timer over again if ~30 minutes has passed
- count = 0;
- deltat= 0;
- lastUpdate = t.read_us();
+ //----Complementary filter
+ th_x = 0.95*(th_x + (pre_gx + gx) * delt_t/2.0f) + 0.05*th_ax;
+ th_y = 0.95*(th_y + (pre_gy + gy) * delt_t/2.0f) + 0.05*th_ay;
+
+ //----Extended Kalman filter
+ dt0_ekf = t.read_us();
+ ekf.ExtendedKalmanFilterUpdate(th_ax, th_ay, pre_gx, pre_gy, pre_gz);
+ dt1_ekf = t.read_us() - dt0_ekf;
+
+ //----Madgwick filter
+ dt0_mwf = t.read_us();
+ mpu9250.MadgwickFilterUpdate_6axis(ax, ay, az, gx, gy, gz);
+ roll = atan2(2.0f * (q1 * q2 + q3 * q4), q1 * q1 - q2 * q2 - q3 * q3 + q4 * q4);
+ roll *= 180.0f / PI;
+ //roll = 0.995f*pre_roll + 0.005f*roll;
+
+ pitch = -asin(2.0f * (q2 * q4 - q1 * q3));
+ pitch *= 180.0f / PI;
+ //pitch = 0.995f*pre_pitch + 0.005f*pitch;
+ dt1_mwf = t.read_us() - dt0_mwf;
+
+ pre_roll = roll;
+ pre_pitch = pitch;
+
+ //----Serial print
+ sum_dt += delt_t;
+ if (sum_dt > 0.0050f)
+ {
+ //pc.printf("%f, %f\n", dt1_ekf, dt1_mwf);
+ pc.printf("%8.3f , %8.3f , %8.3f ,%8.3f\n", t.read(), th_x, th_y, estAlpha, estBeta);
+ sum_dt = 0.0f;
+ }
}
- sum = 0;
- sumCount = 0;
}
-}
-
- }
\ No newline at end of file