MPU6050 Pedometer

Dependencies:   mbed

Pedometer using the MPU6050

Files at this revision

API Documentation at this revision

Comitter:
kohlerba
Date:
Tue Nov 21 20:37:39 2017 +0000
Commit message:
A pedometer using the MAX30100 6DOF module

Changed in this revision

.gitignore Show annotated file Show diff for this revision Revisions of this file
MPU6050.h Show annotated file Show diff for this revision Revisions of this file
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diff -r 000000000000 -r 93289d2d6bce .gitignore
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/.gitignore	Tue Nov 21 20:37:39 2017 +0000
@@ -0,0 +1,4 @@
+.build
+.mbed
+projectfiles
+*.py*
diff -r 000000000000 -r 93289d2d6bce MPU6050.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MPU6050.h	Tue Nov 21 20:37:39 2017 +0000
@@ -0,0 +1,686 @@
+#ifndef MPU6050_H
+#define MPU6050_H
+ 
+#include "mbed.h"
+#include "math.h"
+ 
+ // Define registers per MPU6050, Register Map and Descriptions, Rev 4.2, 08/19/2013 6 DOF Motion sensor fusion device
+// Invensense Inc., www.invensense.com
+// See also MPU-6050 Register Map and Descriptions, Revision 4.0, RM-MPU-6050A-00, 9/12/2012 for registers not listed in 
+// above document; the MPU6050 and MPU 9150 are virtually identical but the latter has an on-board magnetic sensor
+//
+#define XGOFFS_TC        0x00 // Bit 7 PWR_MODE, bits 6:1 XG_OFFS_TC, bit 0 OTP_BNK_VLD                 
+#define YGOFFS_TC        0x01                                                                          
+#define ZGOFFS_TC        0x02
+#define X_FINE_GAIN      0x03 // [7:0] fine gain
+#define Y_FINE_GAIN      0x04
+#define Z_FINE_GAIN      0x05
+#define XA_OFFSET_H      0x06 // User-defined trim values for accelerometer
+#define XA_OFFSET_L_TC   0x07
+#define YA_OFFSET_H      0x08
+#define YA_OFFSET_L_TC   0x09
+#define ZA_OFFSET_H      0x0A
+#define ZA_OFFSET_L_TC   0x0B
+#define SELF_TEST_X      0x0D
+#define SELF_TEST_Y      0x0E    
+#define SELF_TEST_Z      0x0F
+#define SELF_TEST_A      0x10
+#define XG_OFFS_USRH     0x13  // User-defined trim values for gyroscope; supported in MPU-6050?
+#define XG_OFFS_USRL     0x14
+#define YG_OFFS_USRH     0x15
+#define YG_OFFS_USRL     0x16
+#define ZG_OFFS_USRH     0x17
+#define ZG_OFFS_USRL     0x18
+#define SMPLRT_DIV       0x19
+#define CONFIG           0x1A
+#define GYRO_CONFIG      0x1B
+#define ACCEL_CONFIG     0x1C
+#define FF_THR           0x1D  // Free-fall
+#define FF_DUR           0x1E  // Free-fall
+#define MOT_THR          0x1F  // Motion detection threshold bits [7:0]
+#define MOT_DUR          0x20  // Duration counter threshold for motion interrupt generation, 1 kHz rate, LSB = 1 ms
+#define ZMOT_THR         0x21  // Zero-motion detection threshold bits [7:0]
+#define ZRMOT_DUR        0x22  // Duration counter threshold for zero motion interrupt generation, 16 Hz rate, LSB = 64 ms
+#define FIFO_EN          0x23
+#define I2C_MST_CTRL     0x24   
+#define I2C_SLV0_ADDR    0x25
+#define I2C_SLV0_REG     0x26
+#define I2C_SLV0_CTRL    0x27
+#define I2C_SLV1_ADDR    0x28
+#define I2C_SLV1_REG     0x29
+#define I2C_SLV1_CTRL    0x2A
+#define I2C_SLV2_ADDR    0x2B
+#define I2C_SLV2_REG     0x2C
+#define I2C_SLV2_CTRL    0x2D
+#define I2C_SLV3_ADDR    0x2E
+#define I2C_SLV3_REG     0x2F
+#define I2C_SLV3_CTRL    0x30
+#define I2C_SLV4_ADDR    0x31
+#define I2C_SLV4_REG     0x32
+#define I2C_SLV4_DO      0x33
+#define I2C_SLV4_CTRL    0x34
+#define I2C_SLV4_DI      0x35
+#define I2C_MST_STATUS   0x36
+#define INT_PIN_CFG      0x37
+#define INT_ENABLE       0x38
+#define DMP_INT_STATUS   0x39  // Check DMP interrupt
+#define INT_STATUS       0x3A
+#define ACCEL_XOUT_H     0x3B
+#define ACCEL_XOUT_L     0x3C
+#define ACCEL_YOUT_H     0x3D
+#define ACCEL_YOUT_L     0x3E
+#define ACCEL_ZOUT_H     0x3F
+#define ACCEL_ZOUT_L     0x40
+#define TEMP_OUT_H       0x41
+#define TEMP_OUT_L       0x42
+#define GYRO_XOUT_H      0x43
+#define GYRO_XOUT_L      0x44
+#define GYRO_YOUT_H      0x45
+#define GYRO_YOUT_L      0x46
+#define GYRO_ZOUT_H      0x47
+#define GYRO_ZOUT_L      0x48
+#define EXT_SENS_DATA_00 0x49
+#define EXT_SENS_DATA_01 0x4A
+#define EXT_SENS_DATA_02 0x4B
+#define EXT_SENS_DATA_03 0x4C
+#define EXT_SENS_DATA_04 0x4D
+#define EXT_SENS_DATA_05 0x4E
+#define EXT_SENS_DATA_06 0x4F
+#define EXT_SENS_DATA_07 0x50
+#define EXT_SENS_DATA_08 0x51
+#define EXT_SENS_DATA_09 0x52
+#define EXT_SENS_DATA_10 0x53
+#define EXT_SENS_DATA_11 0x54
+#define EXT_SENS_DATA_12 0x55
+#define EXT_SENS_DATA_13 0x56
+#define EXT_SENS_DATA_14 0x57
+#define EXT_SENS_DATA_15 0x58
+#define EXT_SENS_DATA_16 0x59
+#define EXT_SENS_DATA_17 0x5A
+#define EXT_SENS_DATA_18 0x5B
+#define EXT_SENS_DATA_19 0x5C
+#define EXT_SENS_DATA_20 0x5D
+#define EXT_SENS_DATA_21 0x5E
+#define EXT_SENS_DATA_22 0x5F
+#define EXT_SENS_DATA_23 0x60
+#define MOT_DETECT_STATUS 0x61
+#define I2C_SLV0_DO      0x63
+#define I2C_SLV1_DO      0x64
+#define I2C_SLV2_DO      0x65
+#define I2C_SLV3_DO      0x66
+#define I2C_MST_DELAY_CTRL 0x67
+#define SIGNAL_PATH_RESET  0x68
+#define MOT_DETECT_CTRL   0x69
+#define USER_CTRL        0x6A  // Bit 7 enable DMP, bit 3 reset DMP
+#define PWR_MGMT_1       0x6B // Device defaults to the SLEEP mode
+#define PWR_MGMT_2       0x6C
+#define DMP_BANK         0x6D  // Activates a specific bank in the DMP
+#define DMP_RW_PNT       0x6E  // Set read/write pointer to a specific start address in specified DMP bank
+#define DMP_REG          0x6F  // Register in DMP from which to read or to which to write
+#define DMP_REG_1        0x70
+#define DMP_REG_2        0x71
+#define FIFO_COUNTH      0x72
+#define FIFO_COUNTL      0x73
+#define FIFO_R_W         0x74
+#define WHO_AM_I_MPU6050 0x75 // Should return 0x68
+
+// Using the GY-521 breakout board, I set ADO to 0 by grounding through a 4k7 resistor
+// Seven-bit device address is 110100 for ADO = 0 and 110101 for ADO = 1
+#define ADO 0
+#if ADO
+#define MPU6050_ADDRESS 0x69<<1  // Device address when ADO = 1
+#else
+#define MPU6050_ADDRESS 0x68<<1  // Device address when ADO = 0
+#endif
+
+// Set initial input parameters
+enum Ascale {
+  AFS_2G = 0,
+  AFS_4G,
+  AFS_8G,
+  AFS_16G
+};
+
+enum Gscale {
+  GFS_250DPS = 0,
+  GFS_500DPS,
+  GFS_1000DPS,
+  GFS_2000DPS
+};
+
+// Specify sensor full scale
+int Gscale = GFS_250DPS;
+int Ascale = AFS_2G;
+
+//Set up I2C, (SDA,SCL)
+I2C i2c(I2C_SDA, I2C_SCL);
+
+DigitalOut myled(LED1);
+   
+float aRes, gRes; // scale resolutions per LSB for the sensors
+  
+// Pin definitions
+int intPin = 12;  // These can be changed, 2 and 3 are the Arduinos ext int pins
+
+int16_t accelCount[3];  // Stores the 16-bit signed accelerometer sensor output
+float ax, ay, az;       // Stores the real accel value in g's
+int16_t gyroCount[3];   // Stores the 16-bit signed gyro sensor output
+float gx, gy, gz;       // Stores the real gyro value in degrees per seconds
+float gyroBias[3] = {0, 0, 0}, accelBias[3] = {0, 0, 0}; // Bias corrections for gyro and accelerometer
+int16_t tempCount;   // Stores the real internal chip temperature in degrees Celsius
+float temperature;
+float SelfTest[6];
+
+int delt_t = 0; // used to control display output rate
+int count = 0;  // used to control display output rate
+
+// parameters for 6 DoF sensor fusion calculations
+float PI = 3.14159265358979323846f;
+float GyroMeasError = PI * (60.0f / 180.0f);     // gyroscope measurement error in rads/s (start at 60 deg/s), then reduce after ~10 s to 3
+float beta = sqrt(3.0f / 4.0f) * GyroMeasError;  // compute beta
+float GyroMeasDrift = PI * (1.0f / 180.0f);      // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s)
+float zeta = sqrt(3.0f / 4.0f) * GyroMeasDrift;  // compute zeta, the other free parameter in the Madgwick scheme usually set to a small or zero value
+float pitch, yaw, roll;
+float deltat = 0.0f;                              // integration interval for both filter schemes
+int lastUpdate = 0, firstUpdate = 0, Now = 0;     // used to calculate integration interval                               // used to calculate integration interval
+float q[4] = {1.0f, 0.0f, 0.0f, 0.0f};            // vector to hold quaternion
+
+class MPU6050 {
+ 
+    protected:
+ 
+    public:
+  //===================================================================================================================
+//====== Set of useful function to access acceleratio, gyroscope, and temperature data
+//===================================================================================================================
+
+    void writeByte(uint8_t address, uint8_t subAddress, uint8_t data)
+{
+   char data_write[2];
+   data_write[0] = subAddress;
+   data_write[1] = data;
+   i2c.write(address, data_write, 2, 0);
+}
+
+    char readByte(uint8_t address, uint8_t subAddress)
+{
+    char data[1]; // `data` will store the register data     
+    char data_write[1];
+    data_write[0] = subAddress;
+    i2c.write(address, data_write, 1, 1); // no stop
+    i2c.read(address, data, 1, 0); 
+    return data[0]; 
+}
+ 
+    void readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest)
+{     
+    char data[14];
+    char data_write[1];
+    data_write[0] = subAddress;
+    i2c.write(address, data_write, 1, 1); // no stop
+    i2c.read(address, data, count, 0); 
+    for(int ii = 0; ii < count; ii++) {
+     dest[ii] = data[ii];
+    }
+} 
+ 
+
+void getGres() {
+  switch (Gscale)
+  {
+    // Possible gyro scales (and their register bit settings) are:
+    // 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS  (11). 
+        // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
+    case GFS_250DPS:
+          gRes = 250.0/32768.0;
+          break;
+    case GFS_500DPS:
+          gRes = 500.0/32768.0;
+          break;
+    case GFS_1000DPS:
+          gRes = 1000.0/32768.0;
+          break;
+    case GFS_2000DPS:
+          gRes = 2000.0/32768.0;
+          break;
+  }
+}
+
+void getAres() {
+  switch (Ascale)
+  {
+    // Possible accelerometer scales (and their register bit settings) are:
+    // 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs  (11). 
+        // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
+    case AFS_2G:
+          aRes = 2.0/32768.0;
+          break;
+    case AFS_4G:
+          aRes = 4.0/32768.0;
+          break;
+    case AFS_8G:
+          aRes = 8.0/32768.0;
+          break;
+    case AFS_16G:
+          aRes = 16.0/32768.0;
+          break;
+  }
+}
+
+
+void readAccelData(int16_t * destination)
+{
+  uint8_t rawData[6];  // x/y/z accel register data stored here
+  readBytes(MPU6050_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]);  // Read the six raw data registers into data array
+  destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ;  // Turn the MSB and LSB into a signed 16-bit value
+  destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;  
+  destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; 
+}
+
+void readGyroData(int16_t * destination)
+{
+  uint8_t rawData[6];  // x/y/z gyro register data stored here
+  readBytes(MPU6050_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]);  // Read the six raw data registers sequentially into data array
+  destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ;  // Turn the MSB and LSB into a signed 16-bit value
+  destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;  
+  destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; 
+}
+
+int16_t readTempData()
+{
+  uint8_t rawData[2];  // x/y/z gyro register data stored here
+  readBytes(MPU6050_ADDRESS, TEMP_OUT_H, 2, &rawData[0]);  // Read the two raw data registers sequentially into data array 
+  return (int16_t)(((int16_t)rawData[0]) << 8 | rawData[1]) ;  // Turn the MSB and LSB into a 16-bit value
+}
+
+
+
+// Configure the motion detection control for low power accelerometer mode
+void LowPowerAccelOnly()
+{
+
+// The sensor has a high-pass filter necessary to invoke to allow the sensor motion detection algorithms work properly
+// Motion detection occurs on free-fall (acceleration below a threshold for some time for all axes), motion (acceleration
+// above a threshold for some time on at least one axis), and zero-motion toggle (acceleration on each axis less than a 
+// threshold for some time sets this flag, motion above the threshold turns it off). The high-pass filter takes gravity out
+// consideration for these threshold evaluations; otherwise, the flags would be set all the time!
+  
+  uint8_t c = readByte(MPU6050_ADDRESS, PWR_MGMT_1);
+  writeByte(MPU6050_ADDRESS, PWR_MGMT_1, c & ~0x30); // Clear sleep and cycle bits [5:6]
+  writeByte(MPU6050_ADDRESS, PWR_MGMT_1, c |  0x30); // Set sleep and cycle bits [5:6] to zero to make sure accelerometer is running
+
+  c = readByte(MPU6050_ADDRESS, PWR_MGMT_2);
+  writeByte(MPU6050_ADDRESS, PWR_MGMT_2, c & ~0x38); // Clear standby XA, YA, and ZA bits [3:5]
+  writeByte(MPU6050_ADDRESS, PWR_MGMT_2, c |  0x00); // Set XA, YA, and ZA bits [3:5] to zero to make sure accelerometer is running
+    
+  c = readByte(MPU6050_ADDRESS, ACCEL_CONFIG);
+  writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, c & ~0x07); // Clear high-pass filter bits [2:0]
+// Set high-pass filter to 0) reset (disable), 1) 5 Hz, 2) 2.5 Hz, 3) 1.25 Hz, 4) 0.63 Hz, or 7) Hold
+  writeByte(MPU6050_ADDRESS, ACCEL_CONFIG,  c | 0x00);  // Set ACCEL_HPF to 0; reset mode disbaling high-pass filter
+
+  c = readByte(MPU6050_ADDRESS, CONFIG);
+  writeByte(MPU6050_ADDRESS, CONFIG, c & ~0x07); // Clear low-pass filter bits [2:0]
+  writeByte(MPU6050_ADDRESS, CONFIG, c |  0x00);  // Set DLPD_CFG to 0; 260 Hz bandwidth, 1 kHz rate
+    
+  c = readByte(MPU6050_ADDRESS, INT_ENABLE);
+  writeByte(MPU6050_ADDRESS, INT_ENABLE, c & ~0xFF);  // Clear all interrupts
+  writeByte(MPU6050_ADDRESS, INT_ENABLE, 0x40);  // Enable motion threshold (bits 5) interrupt only
+  
+// Motion detection interrupt requires the absolute value of any axis to lie above the detection threshold
+// for at least the counter duration
+  writeByte(MPU6050_ADDRESS, MOT_THR, 0x80); // Set motion detection to 0.256 g; LSB = 2 mg
+  writeByte(MPU6050_ADDRESS, MOT_DUR, 0x01); // Set motion detect duration to 1  ms; LSB is 1 ms @ 1 kHz rate
+  
+  wait(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 resetMPU6050() {
+  // reset device
+  writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
+  wait(0.1);
+  }
+  
+  
+void initMPU6050()
+{  
+ // Initialize MPU6050 device
+ // 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
+  uint16_t ii, packet_count, fifo_count;
+  int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0};
+  
+// reset device, reset all registers, clear gyro and accelerometer bias registers
+  writeByte(MPU6050_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
+  wait(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
+ 
+  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[0]); // read FIFO sample count
+  fifo_count = ((uint16_t)data[0] << 8) | data[1];
+  packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging
+
+  for (ii = 0; ii < packet_count; ii++) {
+    int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0};
+    readBytes(MPU6050_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging
+    accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1]  ) ;  // Form signed 16-bit integer for each sample in FIFO
+    accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3]  ) ;
+    accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5]  ) ;    
+    gyro_temp[0]  = (int16_t) (((int16_t)data[6] << 8) | data[7]  ) ;
+    gyro_temp[1]  = (int16_t) (((int16_t)data[8] << 8) | data[9]  ) ;
+    gyro_temp[2]  = (int16_t) (((int16_t)data[10] << 8) | data[11]) ;
+    
+    accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases
+    accel_bias[1] += (int32_t) accel_temp[1];
+    accel_bias[2] += (int32_t) accel_temp[2];
+    gyro_bias[0]  += (int32_t) gyro_temp[0];
+    gyro_bias[1]  += (int32_t) gyro_temp[1];
+    gyro_bias[2]  += (int32_t) gyro_temp[2];
+            
+}
+    accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases
+    accel_bias[1] /= (int32_t) packet_count;
+    accel_bias[2] /= (int32_t) packet_count;
+    gyro_bias[0]  /= (int32_t) packet_count;
+    gyro_bias[1]  /= (int32_t) packet_count;
+    gyro_bias[2]  /= (int32_t) packet_count;
+    
+  if(accel_bias[2] > 0L) {accel_bias[2] -= (int32_t) accelsensitivity;}  // Remove gravity from the z-axis accelerometer bias calculation
+  else {accel_bias[2] += (int32_t) accelsensitivity;}
+ 
+// Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup
+  data[0] = (-gyro_bias[0]/4  >> 8) & 0xFF; // Divide by 4 to get 32.9 LSB per deg/s to conform to expected bias input format
+  data[1] = (-gyro_bias[0]/4)       & 0xFF; // Biases are additive, so change sign on calculated average gyro biases
+  data[2] = (-gyro_bias[1]/4  >> 8) & 0xFF;
+  data[3] = (-gyro_bias[1]/4)       & 0xFF;
+  data[4] = (-gyro_bias[2]/4  >> 8) & 0xFF;
+  data[5] = (-gyro_bias[2]/4)       & 0xFF;
+
+// Push gyro biases to hardware registers
+  writeByte(MPU6050_ADDRESS, XG_OFFS_USRH, data[0]); 
+  writeByte(MPU6050_ADDRESS, XG_OFFS_USRL, data[1]);
+  writeByte(MPU6050_ADDRESS, YG_OFFS_USRH, data[2]);
+  writeByte(MPU6050_ADDRESS, YG_OFFS_USRL, data[3]);
+  writeByte(MPU6050_ADDRESS, ZG_OFFS_USRH, data[4]);
+  writeByte(MPU6050_ADDRESS, ZG_OFFS_USRL, data[5]);
+
+  dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction
+  dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity;
+  dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity;
+
+// Construct the accelerometer biases for push to the hardware accelerometer bias registers. These registers contain
+// factory trim values which must be added to the calculated accelerometer biases; on boot up these registers will hold
+// non-zero values. In addition, bit 0 of the lower byte must be preserved since it is used for temperature
+// compensation calculations. Accelerometer bias registers expect bias input as 2048 LSB per g, so that
+// the accelerometer biases calculated above must be divided by 8.
+
+  int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases
+  readBytes(MPU6050_ADDRESS, XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values
+  accel_bias_reg[0] = (int16_t) ((int16_t)data[0] << 8) | data[1];
+  readBytes(MPU6050_ADDRESS, YA_OFFSET_H, 2, &data[0]);
+  accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1];
+  readBytes(MPU6050_ADDRESS, ZA_OFFSET_H, 2, &data[0]);
+  accel_bias_reg[2] = (int16_t) ((int16_t)data[0] << 8) | data[1];
+  
+  uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers
+  uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis
+  
+  for(ii = 0; ii < 3; ii++) {
+    if(accel_bias_reg[ii] & mask) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit
+  }
+
+  // Construct total accelerometer bias, including calculated average accelerometer bias from above
+  accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale)
+  accel_bias_reg[1] -= (accel_bias[1]/8);
+  accel_bias_reg[2] -= (accel_bias[2]/8);
+ 
+  data[0] = (accel_bias_reg[0] >> 8) & 0xFF;
+  data[1] = (accel_bias_reg[0])      & 0xFF;
+  data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers
+  data[2] = (accel_bias_reg[1] >> 8) & 0xFF;
+  data[3] = (accel_bias_reg[1])      & 0xFF;
+  data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers
+  data[4] = (accel_bias_reg[2] >> 8) & 0xFF;
+  data[5] = (accel_bias_reg[2])      & 0xFF;
+  data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers
+
+  // Push accelerometer biases to hardware registers
+//  writeByte(MPU6050_ADDRESS, XA_OFFSET_H, data[0]);  
+//  writeByte(MPU6050_ADDRESS, XA_OFFSET_L_TC, data[1]);
+//  writeByte(MPU6050_ADDRESS, YA_OFFSET_H, data[2]);
+//  writeByte(MPU6050_ADDRESS, YA_OFFSET_L_TC, data[3]);  
+//  writeByte(MPU6050_ADDRESS, ZA_OFFSET_H, data[4]);
+//  writeByte(MPU6050_ADDRESS, ZA_OFFSET_L_TC, data[5]);
+
+// Output scaled accelerometer biases for manual subtraction in the main program
+   dest2[0] = (float)accel_bias[0]/(float)accelsensitivity; 
+   dest2[1] = (float)accel_bias[1]/(float)accelsensitivity;
+   dest2[2] = (float)accel_bias[2]/(float)accelsensitivity;
+}
+
+
+// Accelerometer and gyroscope self test; check calibration wrt factory settings
+void MPU6050SelfTest(float * destination) // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass
+{
+   uint8_t rawData[4] = {0, 0, 0, 0};
+   uint8_t selfTest[6];
+   float factoryTrim[6];
+   
+   // Configure the accelerometer for self-test
+   writeByte(MPU6050_ADDRESS, ACCEL_CONFIG, 0xF0); // Enable self test on all three axes and set accelerometer range to +/- 8 g
+   writeByte(MPU6050_ADDRESS, GYRO_CONFIG,  0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s
+   wait(0.25);  // Delay a while to let the device execute the self-test
+   rawData[0] = readByte(MPU6050_ADDRESS, SELF_TEST_X); // X-axis self-test results
+   rawData[1] = readByte(MPU6050_ADDRESS, SELF_TEST_Y); // Y-axis self-test results
+   rawData[2] = readByte(MPU6050_ADDRESS, SELF_TEST_Z); // Z-axis self-test results
+   rawData[3] = readByte(MPU6050_ADDRESS, SELF_TEST_A); // Mixed-axis self-test results
+   // Extract the acceleration test results first
+   selfTest[0] = (rawData[0] >> 3) | (rawData[3] & 0x30) >> 4 ; // XA_TEST result is a five-bit unsigned integer
+   selfTest[1] = (rawData[1] >> 3) | (rawData[3] & 0x0C) >> 4 ; // YA_TEST result is a five-bit unsigned integer
+   selfTest[2] = (rawData[2] >> 3) | (rawData[3] & 0x03) >> 4 ; // ZA_TEST result is a five-bit unsigned integer
+   // Extract the gyration test results first
+   selfTest[3] = rawData[0]  & 0x1F ; // XG_TEST result is a five-bit unsigned integer
+   selfTest[4] = rawData[1]  & 0x1F ; // YG_TEST result is a five-bit unsigned integer
+   selfTest[5] = rawData[2]  & 0x1F ; // ZG_TEST result is a five-bit unsigned integer   
+   // Process results to allow final comparison with factory set values
+   factoryTrim[0] = (4096.0f*0.34f)*(pow( (0.92f/0.34f) , ((selfTest[0] - 1.0f)/30.0f))); // FT[Xa] factory trim calculation
+   factoryTrim[1] = (4096.0f*0.34f)*(pow( (0.92f/0.34f) , ((selfTest[1] - 1.0f)/30.0f))); // FT[Ya] factory trim calculation
+   factoryTrim[2] = (4096.0f*0.34f)*(pow( (0.92f/0.34f) , ((selfTest[2] - 1.0f)/30.0f))); // FT[Za] factory trim calculation
+   factoryTrim[3] =  ( 25.0f*131.0f)*(pow( 1.046f , (selfTest[3] - 1.0f) ));             // FT[Xg] factory trim calculation
+   factoryTrim[4] =  (-25.0f*131.0f)*(pow( 1.046f , (selfTest[4] - 1.0f) ));             // FT[Yg] factory trim calculation
+   factoryTrim[5] =  ( 25.0f*131.0f)*(pow( 1.046f , (selfTest[5] - 1.0f) ));             // FT[Zg] factory trim calculation
+   
+ //  Output self-test results and factory trim calculation if desired
+ //  Serial.println(selfTest[0]); Serial.println(selfTest[1]); Serial.println(selfTest[2]);
+ //  Serial.println(selfTest[3]); Serial.println(selfTest[4]); Serial.println(selfTest[5]);
+ //  Serial.println(factoryTrim[0]); Serial.println(factoryTrim[1]); Serial.println(factoryTrim[2]);
+ //  Serial.println(factoryTrim[3]); Serial.println(factoryTrim[4]); Serial.println(factoryTrim[5]);
+
+ // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response
+ // To get to percent, must multiply by 100 and subtract result from 100
+   for (int i = 0; i < 6; i++) {
+     destination[i] = 100.0f + 100.0f*(selfTest[i] - factoryTrim[i])/factoryTrim[i]; // Report percent differences
+   }
+   
+}
+
+
+// Implementation of Sebastian Madgwick's "...efficient orientation filter for... inertial/magnetic sensor arrays"
+// (see http://www.x-io.co.uk/category/open-source/ for examples and more details)
+// which fuses acceleration and rotation rate to produce a quaternion-based estimate of relative
+// device orientation -- which can be converted to yaw, pitch, and roll. Useful for stabilizing quadcopters, etc.
+// The performance of the orientation filter is at least as good as conventional Kalman-based filtering algorithms
+// but is much less computationally intensive---it can be performed on a 3.3 V Pro Mini operating at 8 MHz!
+        void MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz)
+        {
+            float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3];         // short name local variable for readability
+            float norm;                                               // vector norm
+            float f1, f2, f3;                                         // objective funcyion elements
+            float J_11or24, J_12or23, J_13or22, J_14or21, J_32, J_33; // objective function Jacobian elements
+            float qDot1, qDot2, qDot3, qDot4;
+            float hatDot1, hatDot2, hatDot3, hatDot4;
+            float gerrx, gerry, gerrz, gbiasx, gbiasy, gbiasz;  // gyro bias error
+
+            // Auxiliary variables to avoid repeated arithmetic
+            float _halfq1 = 0.5f * q1;
+            float _halfq2 = 0.5f * q2;
+            float _halfq3 = 0.5f * q3;
+            float _halfq4 = 0.5f * q4;
+            float _2q1 = 2.0f * q1;
+            float _2q2 = 2.0f * q2;
+            float _2q3 = 2.0f * q3;
+            float _2q4 = 2.0f * q4;
+//            float _2q1q3 = 2.0f * q1 * q3;
+//            float _2q3q4 = 2.0f * q3 * q4;
+
+            // Normalise accelerometer measurement
+            norm = sqrt(ax * ax + ay * ay + az * az);
+            if (norm == 0.0f) return; // handle NaN
+            norm = 1.0f/norm;
+            ax *= norm;
+            ay *= norm;
+            az *= norm;
+            
+            // Compute the objective function and Jacobian
+            f1 = _2q2 * q4 - _2q1 * q3 - ax;
+            f2 = _2q1 * q2 + _2q3 * q4 - ay;
+            f3 = 1.0f - _2q2 * q2 - _2q3 * q3 - az;
+            J_11or24 = _2q3;
+            J_12or23 = _2q4;
+            J_13or22 = _2q1;
+            J_14or21 = _2q2;
+            J_32 = 2.0f * J_14or21;
+            J_33 = 2.0f * J_11or24;
+          
+            // Compute the gradient (matrix multiplication)
+            hatDot1 = J_14or21 * f2 - J_11or24 * f1;
+            hatDot2 = J_12or23 * f1 + J_13or22 * f2 - J_32 * f3;
+            hatDot3 = J_12or23 * f2 - J_33 *f3 - J_13or22 * f1;
+            hatDot4 = J_14or21 * f1 + J_11or24 * f2;
+            
+            // Normalize the gradient
+            norm = sqrt(hatDot1 * hatDot1 + hatDot2 * hatDot2 + hatDot3 * hatDot3 + hatDot4 * hatDot4);
+            hatDot1 /= norm;
+            hatDot2 /= norm;
+            hatDot3 /= norm;
+            hatDot4 /= norm;
+            
+            // Compute estimated gyroscope biases
+            gerrx = _2q1 * hatDot2 - _2q2 * hatDot1 - _2q3 * hatDot4 + _2q4 * hatDot3;
+            gerry = _2q1 * hatDot3 + _2q2 * hatDot4 - _2q3 * hatDot1 - _2q4 * hatDot2;
+            gerrz = _2q1 * hatDot4 - _2q2 * hatDot3 + _2q3 * hatDot2 - _2q4 * hatDot1;
+            
+            // Compute and remove gyroscope biases
+            gbiasx += gerrx * deltat * zeta;
+            gbiasy += gerry * deltat * zeta;
+            gbiasz += gerrz * deltat * zeta;
+ //           gx -= gbiasx;
+ //           gy -= gbiasy;
+ //           gz -= gbiasz;
+            
+            // Compute the quaternion derivative
+            qDot1 = -_halfq2 * gx - _halfq3 * gy - _halfq4 * gz;
+            qDot2 =  _halfq1 * gx + _halfq3 * gz - _halfq4 * gy;
+            qDot3 =  _halfq1 * gy - _halfq2 * gz + _halfq4 * gx;
+            qDot4 =  _halfq1 * gz + _halfq2 * gy - _halfq3 * gx;
+
+            // Compute then integrate estimated quaternion derivative
+            q1 += (qDot1 -(beta * hatDot1)) * deltat;
+            q2 += (qDot2 -(beta * hatDot2)) * deltat;
+            q3 += (qDot3 -(beta * hatDot3)) * deltat;
+            q4 += (qDot4 -(beta * hatDot4)) * deltat;
+
+            // Normalize the quaternion
+            norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4);    // normalise quaternion
+            norm = 1.0f/norm;
+            q[0] = q1 * norm;
+            q[1] = q2 * norm;
+            q[2] = q3 * norm;
+            q[3] = q4 * norm;
+            
+        }
+        
+  
+  };
+#endif
\ No newline at end of file
diff -r 000000000000 -r 93289d2d6bce main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Tue Nov 21 20:37:39 2017 +0000
@@ -0,0 +1,390 @@
+#include "mbed.h"
+#include "MPU6050.h"
+
+InterruptIn button(USER_BUTTON);
+DigitalOut led(LED1);
+
+Serial pc(USBTX, USBRX); // tx, rx
+
+MPU6050 mpu6050;
+
+Timer t;
+Timer step_timer;
+
+#define AVERAGE_BUFF_SIZE 20
+
+float ax_fl;
+float ay_fl;
+float az_fl;
+
+int ax_int;
+int ay_int;
+int az_int;
+
+int ax_avg_buff[AVERAGE_BUFF_SIZE];
+int ax_avg_buff_count = 0;
+int ax_avg;
+int ay_avg_buff[AVERAGE_BUFF_SIZE];
+int ay_avg_buff_count = 0;
+int ay_avg;
+int az_avg_buff[AVERAGE_BUFF_SIZE];
+int az_avg_buff_count = 0;
+int az_avg;
+
+int now;
+int step_timer_now;
+int min_reg_ax;
+int min_current_ax;
+int min_reg_ay;
+int min_current_ay;
+int min_reg_az;
+int min_current_az;
+int max_reg_ax;
+int max_current_ax;
+int max_reg_ay;
+int max_current_ay;
+int max_reg_az;
+int max_current_az;
+int dy_thres_ax;
+int dy_thres_ay;
+int dy_thres_az;
+int dy_chan_ax;
+int dy_chan_ay;
+int dy_chan_az;
+
+int active_axis;
+
+int sample_new;
+int sample_old;
+int sample_result;
+
+int step_size = 200;
+
+int step_count = 0;
+
+//sampling variables
+#define SAMPLE_SIZE 2000
+
+int test_ax[SAMPLE_SIZE];
+int test_ay[SAMPLE_SIZE];
+int test_az[SAMPLE_SIZE];
+int time_ms[SAMPLE_SIZE];
+int count_a = 0;
+int step_times[SAMPLE_SIZE];
+int step_sample_count = 0;
+
+int return_samples = 0;
+//
+
+void pressed(){
+    if(count_a == SAMPLE_SIZE){
+        return_samples = 1;
+    }
+    else{
+        step_times[step_sample_count] = us_ticker_read() / 1000;;
+        step_sample_count++;
+    }
+}
+
+int main() {
+    
+    //----------Setup----------//
+    
+    pc.baud(115200);
+    
+    //Set up I2C
+    i2c.frequency(400000);  // use fast (400 kHz) I2C  
+    
+    t.start(); 
+    
+    // Read the WHO_AM_I register, this is a good test of communication
+    uint8_t whoami = mpu6050.readByte(MPU6050_ADDRESS, WHO_AM_I_MPU6050);
+    
+    if (whoami == 0x68){  
+        pc.printf("MPU6050 is online...\n\r");
+        wait(1);
+    }
+    
+    else{
+        pc.printf("MPU6050 is offline...\n\r");
+        pc.printf("Value is %d\n\r",whoami);
+        pc.printf("Should be %d\n\r",0x68);
+        while(1){
+            wait(1);
+        }
+    }
+    
+    mpu6050.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(" percent of factory value \n\r");
+    pc.printf("y-axis self test: acceleration trim within : "); pc.printf("%f", SelfTest[1]); pc.printf(" percent of factory value \n\r");
+    pc.printf("z-axis self test: acceleration trim within : "); pc.printf("%f", SelfTest[2]); pc.printf(" percent of factory value \n\r");
+    pc.printf("x-axis self test: gyration trim within : "); pc.printf("%f", SelfTest[3]); pc.printf(" percent of factory value \n\r");
+    pc.printf("y-axis self test: gyration trim within : "); pc.printf("%f", SelfTest[4]); pc.printf(" percent of factory value \n\r");
+    pc.printf("z-axis self test: gyration trim within : "); pc.printf("%f", SelfTest[5]); pc.printf(" percent of factory value \n\r");
+    wait(1);
+    
+    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) 
+    {
+        mpu6050.resetMPU6050(); // Reset registers to default in preparation for device calibration
+        mpu6050.calibrateMPU6050(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers  
+        mpu6050.initMPU6050(); pc.printf("MPU6050 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature
+    }
+    
+    else
+    {
+        pc.printf("Device did not the pass self-test!\n\r");    
+    }
+    wait(1);
+    
+    //----------Loop----------//
+    
+    while(1){
+        // If data ready bit set, all data registers have new data
+        if(mpu6050.readByte(MPU6050_ADDRESS, INT_STATUS) & 0x01) {  // check if data ready interrupt
+            mpu6050.readAccelData(accelCount);  // Read the x/y/z adc values
+            mpu6050.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];
+            
+            if(ax<0){
+            ax = ax*-1;
+            }
+            if(ay<0){
+            ay = ay*-1;
+            }
+            if(az<0){
+            az = az*-1;
+            }
+            
+            mpu6050.readGyroData(gyroCount);  // Read the x/y/z adc values
+            mpu6050.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 = mpu6050.readTempData();  // Read the x/y/z adc values
+            temperature = (tempCount) / 340. + 36.53; // Temperature in degrees Centigrade
+            
+            // Pass gyro rate as rad/s
+            mpu6050.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f);
+            
+            //accelerometer readings
+            ax_fl = 1000 * ax;
+            ay_fl = 1000 * ay;
+            az_fl = 1000 * az;
+            
+            ax_int = ax_fl;
+            ay_int = ay_fl;
+            az_int = az_fl;
+            //end
+            
+            //average values
+            //ax
+            ax_avg_buff[ax_avg_buff_count] = ax_int;
+            ax_avg_buff_count++;
+            ax_avg_buff_count = ax_avg_buff_count % AVERAGE_BUFF_SIZE;
+            
+            ax_avg = 0;
+            
+            int i;
+            for(i = 0; i < AVERAGE_BUFF_SIZE;i++){
+                ax_avg = ax_avg + ax_avg_buff[i];
+            }
+            
+            ax_avg = ax_avg/AVERAGE_BUFF_SIZE;
+            
+            //ay
+            ay_avg_buff[ay_avg_buff_count] = ay_int;
+            ay_avg_buff_count++;
+            ay_avg_buff_count = ay_avg_buff_count % AVERAGE_BUFF_SIZE;
+            
+            ay_avg = 0;
+            
+            for(i = 0; i < AVERAGE_BUFF_SIZE;i++){
+                ay_avg = ay_avg + ay_avg_buff[i];
+            }
+            
+            ay_avg = ay_avg/AVERAGE_BUFF_SIZE;
+            
+            //az
+            az_avg_buff[az_avg_buff_count] = az_int;
+            az_avg_buff_count++;
+            az_avg_buff_count = az_avg_buff_count % AVERAGE_BUFF_SIZE;
+            
+            az_avg = 0;
+            
+            for(i = 0; i < AVERAGE_BUFF_SIZE;i++){
+                az_avg = az_avg + az_avg_buff[i];
+            }
+            
+            az_avg = az_avg/AVERAGE_BUFF_SIZE;
+            //end
+            
+            //algorithum readings
+            now = t.read_ms();
+            if(now>=500){
+                t.stop();
+                t.reset();
+                min_current_ax = min_reg_ax;
+                max_current_ax = max_reg_ax;
+                dy_thres_ax = (min_current_ax+max_current_ax)/2;
+                dy_chan_ax = (max_current_ax-min_current_ax);
+                min_reg_ax = ax_avg;
+                max_reg_ax = ax_avg;
+                min_current_ay = min_reg_ay;
+                max_current_ay = max_reg_ay;
+                dy_thres_ay = (min_current_ay+max_current_ay)/2;
+                dy_chan_ay = (max_current_ay-min_current_ay);
+                min_reg_ay = ay_avg;
+                max_reg_ay = ay_avg;
+                min_current_az = min_reg_az;
+                max_current_az = max_reg_az;
+                dy_thres_az = (min_current_az+max_current_az)/2;
+                dy_chan_az = (max_current_az-min_current_az);
+                min_reg_az = az_avg;
+                max_reg_az = az_avg;
+                
+                //active axis switching
+                if(dy_chan_ax>=dy_chan_ay && dy_chan_ax>= dy_chan_az){
+                    if(active_axis!=0){
+                        sample_old = 0;
+                        sample_new = ax_avg;
+                    }
+                    active_axis = 0;
+                }
+                else if(dy_chan_ay>=dy_chan_ax && dy_chan_ay>=dy_chan_az){
+                    if(active_axis!=1){
+                        sample_old = 0;
+                        sample_new = ay_avg;
+                    }
+                    active_axis = 1;
+                }
+                else{
+                    if(active_axis!=2){
+                        sample_old = 0;
+                        sample_new = az_avg;
+                    }
+                    active_axis = 2;
+                }
+                //end
+                
+                t.start();
+            }
+            else if(now<500){
+                if(min_reg_ax>ax_avg){
+                    min_reg_ax = ax_avg;
+                }
+                if(max_reg_ax<ax_avg){
+                    max_reg_ax = ax_avg;
+                }
+                if(min_reg_ay>ay_avg){
+                    min_reg_ay = ay_avg;
+                }
+                if(max_reg_ay<ay_avg){
+                    max_reg_ay = ay_avg;
+                }
+                if(min_reg_az>az_avg){
+                    min_reg_az = az_avg;
+                }
+                if(max_reg_az<az_avg){
+                    max_reg_az = az_avg;
+                }
+            }
+            //end
+            
+            //sample
+            sample_old = sample_new;
+            switch(active_axis){
+            case(0): 
+                if(ax_avg-sample_old>step_size || ax_avg-sample_old<-step_size){
+                    sample_new = ax_avg;
+                    if(sample_old>dy_thres_ax && sample_new<dy_thres_ax){
+                        step_count++;
+                    }
+                }
+                break;
+            case(1):
+                if(ay_avg-sample_old>step_size || ay_avg-sample_old<-step_size){
+                    sample_new = ay_avg;
+                    if(sample_old>dy_thres_ay && sample_new<dy_thres_ay){
+                        step_count++;
+                    }
+                }
+                break;
+            case(2):
+                if(az_avg-sample_old>step_size || az_avg-sample_old<-step_size){
+                    sample_new = az_avg;
+                    if(sample_old>dy_thres_az && sample_new<dy_thres_az){
+                        step_count++;
+                    }
+                }
+                break;
+            }
+            
+            //sampling data
+            if(count_a < SAMPLE_SIZE){
+                test_ax[count_a] = ax_int;
+                test_ay[count_a] = ay_int;
+                test_az[count_a] = az_int;
+                time_ms[count_a] = us_ticker_read() / 1000;
+                count_a++;
+            }
+            else if(count_a == SAMPLE_SIZE && return_samples == 1){
+                /*
+                int i;
+                
+                //ax samples
+                pc.printf("ax = [");
+                for(i = 0; i<SAMPLE_SIZE; i++){
+                    pc.printf(" %d ",test_ax[i]);
+                }
+                pc.printf("]\r\n");
+                
+                //ay samples
+                pc.printf("ay = [");
+                for(i = 0; i<SAMPLE_SIZE; i++){
+                    pc.printf(" %d ",test_ay[i]);
+                }
+                pc.printf("]\r\n");
+                
+                //az samples
+                pc.printf("az = [");
+                for(i = 0; i<SAMPLE_SIZE; i++){
+                    pc.printf(" %d ",test_az[i]);
+                }
+                pc.printf("]\r\n");
+                
+                //timer samples
+                pc.printf("t = [");
+                for(i = 0; i<SAMPLE_SIZE; i++){
+                    pc.printf(" %d ",time_ms[i]);
+                }
+                pc.printf("]\r\n");
+                
+                //step samples
+                pc.printf("s = [");
+                for(i = 0; i<SAMPLE_SIZE; i++){
+                    pc.printf(" %d ",step_times[i]);
+                }
+                pc.printf("]\r\n");
+                */
+                count_a++;        
+            }
+            
+            button.fall(&pressed);
+            //end
+            
+            //printing rtd
+            pc.printf("$%d %d %d;", ax_avg, ay_avg, step_count*100);
+            //end
+            
+            //wait 
+            wait_ms(10);
+        }
+    }
+}
diff -r 000000000000 -r 93289d2d6bce mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Tue Nov 21 20:37:39 2017 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/fd96258d940d
\ No newline at end of file