Revision 0:c23e915f255b, committed 2018-08-05

Comitter:

JJting

Date:

Sun Aug 05 13:15:56 2018 +0000

Child:

1:2823a39f70a9

Commit message:

ver1

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LSM9DS1.cpp	Sun Aug 05 13:15:56 2018 +0000
@@ -0,0 +1,401 @@
+#include "LSM9DS1.h"
+
+LSM9DS1::LSM9DS1(PinName sda, PinName scl, uint8_t xgAddr, uint8_t mAddr) : i2c(sda, scl)
+{
+    // xgAddress and mAddress will store the 7-bit I2C address, if using I2C.
+    xgAddress = xgAddr;
+    mAddress = mAddr;
+}
+
+uint16_t LSM9DS1::begin(gyro_scale gScl, accel_scale aScl, mag_scale mScl, 
+                        gyro_odr gODR, accel_odr aODR, mag_odr mODR)
+{
+    // Store the given scales in class variables. These scale variables
+    // are used throughout to calculate the actual g's, DPS,and Gs's.
+    gScale = gScl;
+    aScale = aScl;
+    mScale = mScl;
+    
+    // Once we have the scale values, we can calculate the resolution
+    // of each sensor. That's what these functions are for. One for each sensor
+    calcgRes(); // Calculate DPS / ADC tick, stored in gRes variable
+    calcmRes(); // Calculate Gs / ADC tick, stored in mRes variable
+    calcaRes(); // Calculate g / ADC tick, stored in aRes variable
+    
+    
+    // To verify communication, we can read from the WHO_AM_I register of
+    // each device. Store those in a variable so we can return them.
+    // The start of the addresses we want to read from
+    char cmd[2] = {
+        WHO_AM_I_XG,
+        0
+    };
+
+    // Write the address we are going to read from and don't end the transaction
+    i2c.write(xgAddress, cmd, 1, true);
+    // Read in all the 8 bits of data
+    i2c.read(xgAddress, cmd+1, 1);
+    uint8_t xgTest = cmd[1];                    // Read the accel/gyro WHO_AM_I
+    
+    // Reset to the address of the mag who am i
+    cmd[1] = WHO_AM_I_M;
+    // Write the address we are going to read from and don't end the transaction
+    i2c.write(mAddress, cmd, 1, true);
+    // Read in all the 8 bits of data
+    i2c.read(mAddress, cmd+1, 1);
+    uint8_t mTest = cmd[1];      // Read the mag WHO_AM_I
+    
+    // Gyro initialization stuff:
+    initGyro(); // This will "turn on" the gyro. Setting up interrupts, etc.
+    setGyroODR(gODR); // Set the gyro output data rate and bandwidth.
+    setGyroScale(gScale); // Set the gyro range
+    
+    // Accelerometer initialization stuff:
+    initAccel(); // "Turn on" all axes of the accel. Set up interrupts, etc.
+    setAccelODR(aODR); // Set the accel data rate.
+    setAccelScale(aScale); // Set the accel range.
+    
+    // Magnetometer initialization stuff:
+    initMag(); // "Turn on" all axes of the mag. Set up interrupts, etc.
+    setMagODR(mODR); // Set the magnetometer output data rate.
+    setMagScale(mScale); // Set the magnetometer's range.
+    
+    // Once everything is initialized, return the WHO_AM_I registers we read:
+    return (xgTest << 8) | mTest;
+}
+
+void LSM9DS1::initGyro()
+{
+    char cmd[4] = {
+        CTRL_REG1_G,
+        gScale | G_ODR_119_BW_14,
+        0,          // Default data out and int out
+        0           // Default power mode and high pass settings
+    };
+
+    // Write the data to the gyro control registers
+    i2c.write(xgAddress, cmd, 4);
+}
+
+void LSM9DS1::initAccel()
+{
+    char cmd[4] = {
+        CTRL_REG5_XL,
+        0x38,       // Enable all axis and don't decimate data in out Registers
+        (A_ODR_119 << 5) | (aScale << 3) | (A_BW_AUTO_SCALE),   // 119 Hz ODR, set scale, and auto BW
+        0           // Default resolution mode and filtering settings
+    };
+
+    // Write the data to the accel control registers
+    i2c.write(xgAddress, cmd, 4);
+}
+
+void LSM9DS1::initMag()
+{   
+    char cmd[4] = {
+        CTRL_REG1_M,
+        0x10,       // Default data rate, xy axes mode, and temp comp
+        mScale << 5, // Set mag scale
+        0           // Enable I2C, write only SPI, not LP mode, Continuous conversion mode
+    };
+
+    // Write the data to the mag control registers
+    i2c.write(mAddress, cmd, 4);
+}
+
+void LSM9DS1::readAccel()
+{
+    // The data we are going to read from the accel
+    char data[6];
+
+    // The start of the addresses we want to read from
+    char subAddress = OUT_X_L_XL;
+
+    // Write the address we are going to read from and don't end the transaction
+    i2c.write(xgAddress, &subAddress, 1, true);
+    // Read in all 8 bit registers containing the axes data
+    i2c.read(xgAddress, data, 6);
+
+    // Reassemble the data and convert to g
+    ax_raw = data[0] | (data[1] << 8);
+    ay_raw = data[2] | (data[3] << 8);
+    az_raw = data[4] | (data[5] << 8);
+    ax = ax_raw * aRes;
+    ay = ay_raw * aRes;
+    az = az_raw * aRes;
+}
+
+void LSM9DS1::readMag()
+{
+    // The data we are going to read from the mag
+    char data[6];
+
+    // The start of the addresses we want to read from
+    char subAddress = OUT_X_L_M;
+
+    // Write the address we are going to read from and don't end the transaction
+    i2c.write(mAddress, &subAddress, 1, true);
+    // Read in all 8 bit registers containing the axes data
+    i2c.read(mAddress, data, 6);
+
+    // Reassemble the data and convert to degrees
+    mx_raw = data[0] | (data[1] << 8);
+    my_raw = data[2] | (data[3] << 8);
+    mz_raw = data[4] | (data[5] << 8);
+    mx = mx_raw * mRes;
+    my = my_raw * mRes;
+    mz = mz_raw * mRes;
+}
+
+void LSM9DS1::readTemp()
+{
+    // The data we are going to read from the temp
+    char data[2];
+
+    // The start of the addresses we want to read from
+    char subAddress = OUT_TEMP_L;
+
+    // Write the address we are going to read from and don't end the transaction
+    i2c.write(xgAddress, &subAddress, 1, true);
+    // Read in all 8 bit registers containing the axes data
+    i2c.read(xgAddress, data, 2);
+
+    // Temperature is a 12-bit signed integer   
+    temperature_raw = data[0] | (data[1] << 8);
+
+    temperature_c = (float)temperature_raw / 8.0 + 25;
+    temperature_f = temperature_c * 1.8 + 32;
+}
+
+
+void LSM9DS1::readGyro()
+{
+    // The data we are going to read from the gyro
+    char data[6];
+
+    // The start of the addresses we want to read from
+    char subAddress = OUT_X_L_G;
+
+    // Write the address we are going to read from and don't end the transaction
+    i2c.write(xgAddress, &subAddress, 1, true);
+    // Read in all 8 bit registers containing the axes data
+    i2c.read(xgAddress, data, 6);
+
+    // Reassemble the data and convert to degrees/sec
+    gx_raw = data[0] | (data[1] << 8);
+    gy_raw = data[2] | (data[3] << 8);
+    gz_raw = data[4] | (data[5] << 8);
+    gx = gx_raw * gRes;
+    gy = gy_raw * gRes;
+    gz = gz_raw * gRes;
+}
+
+void LSM9DS1::setGyroScale(gyro_scale gScl)
+{
+    // The start of the addresses we want to read from
+    char cmd[2] = {
+        CTRL_REG1_G,
+        0
+    };
+
+    // Write the address we are going to read from and don't end the transaction
+    i2c.write(xgAddress, cmd, 1, true);
+    // Read in all the 8 bits of data
+    i2c.read(xgAddress, cmd+1, 1);
+
+    // Then mask out the gyro scale bits:
+    cmd[1] &= 0xFF^(0x3 << 3);
+    // Then shift in our new scale bits:
+    cmd[1] |= gScl << 3;
+
+    // Write the gyroscale out to the gyro
+    i2c.write(xgAddress, cmd, 2);
+    
+    // We've updated the sensor, but we also need to update our class variables
+    // First update gScale:
+    gScale = gScl;
+    // Then calculate a new gRes, which relies on gScale being set correctly:
+    calcgRes();
+}
+
+void LSM9DS1::setAccelScale(accel_scale aScl)
+{
+    // The start of the addresses we want to read from
+    char cmd[2] = {
+        CTRL_REG6_XL,
+        0
+    };
+
+    // Write the address we are going to read from and don't end the transaction
+    i2c.write(xgAddress, cmd, 1, true);
+    // Read in all the 8 bits of data
+    i2c.read(xgAddress, cmd+1, 1);
+
+    // Then mask out the accel scale bits:
+    cmd[1] &= 0xFF^(0x3 << 3);
+    // Then shift in our new scale bits:
+    cmd[1] |= aScl << 3;
+
+    // Write the accelscale out to the accel
+    i2c.write(xgAddress, cmd, 2);
+    
+    // We've updated the sensor, but we also need to update our class variables
+    // First update aScale:
+    aScale = aScl;
+    // Then calculate a new aRes, which relies on aScale being set correctly:
+    calcaRes();
+}
+
+void LSM9DS1::setMagScale(mag_scale mScl)
+{
+    // The start of the addresses we want to read from
+    char cmd[2] = {
+        CTRL_REG2_M,
+        0
+    };
+
+    // Write the address we are going to read from and don't end the transaction
+    i2c.write(mAddress, cmd, 1, true);
+    // Read in all the 8 bits of data
+    i2c.read(mAddress, cmd+1, 1);
+
+    // Then mask out the mag scale bits:
+    cmd[1] &= 0xFF^(0x3 << 5);
+    // Then shift in our new scale bits:
+    cmd[1] |= mScl << 5;
+
+    // Write the magscale out to the mag
+    i2c.write(mAddress, cmd, 2);
+    
+    // We've updated the sensor, but we also need to update our class variables
+    // First update mScale:
+    mScale = mScl;
+    // Then calculate a new mRes, which relies on mScale being set correctly:
+    calcmRes();
+}
+
+void LSM9DS1::setGyroODR(gyro_odr gRate)
+{
+    // The start of the addresses we want to read from
+    char cmd[2] = {
+        CTRL_REG1_G,
+        0
+    };
+
+    // Write the address we are going to read from and don't end the transaction
+    i2c.write(xgAddress, cmd, 1, true);
+    // Read in all the 8 bits of data
+    i2c.read(xgAddress, cmd+1, 1);
+
+    // Then mask out the gyro odr bits:
+    cmd[1] &= (0x3 << 3);
+    // Then shift in our new odr bits:
+    cmd[1] |= gRate;
+
+    // Write the gyroodr out to the gyro
+    i2c.write(xgAddress, cmd, 2);
+}
+
+void LSM9DS1::setAccelODR(accel_odr aRate)
+{
+    // The start of the addresses we want to read from
+    char cmd[2] = {
+        CTRL_REG6_XL,
+        0
+    };
+
+    // Write the address we are going to read from and don't end the transaction
+    i2c.write(xgAddress, cmd, 1, true);
+    // Read in all the 8 bits of data
+    i2c.read(xgAddress, cmd+1, 1);
+
+    // Then mask out the accel odr bits:
+    cmd[1] &= 0xFF^(0x7 << 5);
+    // Then shift in our new odr bits:
+    cmd[1] |= aRate << 5;
+
+    // Write the accelodr out to the accel
+    i2c.write(xgAddress, cmd, 2);
+}
+
+void LSM9DS1::setMagODR(mag_odr mRate)
+{
+    // The start of the addresses we want to read from
+    char cmd[2] = {
+        CTRL_REG1_M,
+        0
+    };
+
+    // Write the address we are going to read from and don't end the transaction
+    i2c.write(mAddress, cmd, 1, true);
+    // Read in all the 8 bits of data
+    i2c.read(mAddress, cmd+1, 1);
+
+    // Then mask out the mag odr bits:
+    cmd[1] &= 0xFF^(0x7 << 2);
+    // Then shift in our new odr bits:
+    cmd[1] |= mRate << 2;
+
+    // Write the magodr out to the mag
+    i2c.write(mAddress, cmd, 2);
+}
+
+void LSM9DS1::calcgRes()
+{
+    // Possible gyro scales (and their register bit settings) are:
+    // 245 DPS (00), 500 DPS (01), 2000 DPS (10).
+    switch (gScale)
+    {
+        case G_SCALE_245DPS:
+            gRes = 245.0 / 32768.0;
+            break;
+        case G_SCALE_500DPS:
+            gRes = 500.0 / 32768.0;
+            break;
+        case G_SCALE_2000DPS:
+            gRes = 2000.0 / 32768.0;
+            break;
+    }
+}
+
+void LSM9DS1::calcaRes()
+{
+    // Possible accelerometer scales (and their register bit settings) are:
+    // 2 g (000), 4g (001), 6g (010) 8g (011), 16g (100).
+    switch (aScale)
+    {
+        case A_SCALE_2G:
+            aRes = 2.0 / 32768.0;
+            break;
+        case A_SCALE_4G:
+            aRes = 4.0 / 32768.0;
+            break;
+        case A_SCALE_8G:
+            aRes = 8.0 / 32768.0;
+            break;
+        case A_SCALE_16G:
+            aRes = 16.0 / 32768.0;
+            break;
+    }
+}
+
+void LSM9DS1::calcmRes()
+{
+    // Possible magnetometer scales (and their register bit settings) are:
+    // 2 Gs (00), 4 Gs (01), 8 Gs (10) 12 Gs (11). 
+    switch (mScale)
+    {
+        case M_SCALE_4GS:
+            mRes = 4.0 / 32768.0;
+            break;
+        case M_SCALE_8GS:
+            mRes = 8.0 / 32768.0;
+            break;
+        case M_SCALE_12GS:
+            mRes = 12.0 / 32768.0;
+            break;
+        case M_SCALE_16GS:
+            mRes = 16.0 / 32768.0;
+            break;
+    }
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LSM9DS1.h	Sun Aug 05 13:15:56 2018 +0000
@@ -0,0 +1,386 @@
+#ifndef _LSM9DS1_H__
+#define _LSM9DS1_H__
+
+#include "mbed.h"
+
+#define Acce_gain_z_2 -9.825751072961373f
+#define Acce_gain_y_2 -9.810204081632654f
+#define Acce_gain_x_2 -9.579654120040694
+#define Acce_gain_z   -10.0512295081967213f
+#define Acce_gain_y   -9.9090909090909090f
+#define Acce_gain_x   -9.4236311239193f
+#define Gyro_gain_x    0.02035972509905115f
+#define Gyro_gain_y    0.01825192507334282f
+#define Gyro_gain_z    0.02154843475f
+#define Gyro_gain_x_2 -0.02035972509905115f
+#define Gyro_gain_y_2 -0.01825192507334282f
+#define Gyro_gain_z_2 -0.02154843475f
+#define pi            3.1415926f
+/////////////////////////////////////////
+// LSM9DS1 Accel/Gyro (XL/G) Registers //
+/////////////////////////////////////////
+#define ACT_THS             0x04
+#define ACT_DUR             0x05
+#define INT_GEN_CFG_XL      0x06
+#define INT_GEN_THS_X_XL    0x07
+#define INT_GEN_THS_Y_XL    0x08
+#define INT_GEN_THS_Z_XL    0x09
+#define INT_GEN_DUR_XL      0x0A
+#define REFERENCE_G         0x0B
+#define INT1_CTRL           0x0C
+#define INT2_CTRL           0x0D
+#define WHO_AM_I_XG         0x0F
+#define CTRL_REG1_G         0x10
+#define CTRL_REG2_G         0x11
+#define CTRL_REG3_G         0x12
+#define ORIENT_CFG_G        0x13
+#define INT_GEN_SRC_G       0x14
+#define OUT_TEMP_L          0x15
+#define OUT_TEMP_H          0x16
+#define STATUS_REG_0        0x17
+#define OUT_X_L_G           0x18
+#define OUT_X_H_G           0x19
+#define OUT_Y_L_G           0x1A
+#define OUT_Y_H_G           0x1B
+#define OUT_Z_L_G           0x1C
+#define OUT_Z_H_G           0x1D
+#define CTRL_REG4           0x1E
+#define CTRL_REG5_XL        0x1F
+#define CTRL_REG6_XL        0x20
+#define CTRL_REG7_XL        0x21
+#define CTRL_REG8           0x22
+#define CTRL_REG9           0x23
+#define CTRL_REG10          0x24
+#define INT_GEN_SRC_XL      0x26
+#define STATUS_REG_1        0x27
+#define OUT_X_L_XL          0x28
+#define OUT_X_H_XL          0x29
+#define OUT_Y_L_XL          0x2A
+#define OUT_Y_H_XL          0x2B
+#define OUT_Z_L_XL          0x2C
+#define OUT_Z_H_XL          0x2D
+#define FIFO_CTRL           0x2E
+#define FIFO_SRC            0x2F
+#define INT_GEN_CFG_G       0x30
+#define INT_GEN_THS_XH_G    0x31
+#define INT_GEN_THS_XL_G    0x32
+#define INT_GEN_THS_YH_G    0x33
+#define INT_GEN_THS_YL_G    0x34
+#define INT_GEN_THS_ZH_G    0x35
+#define INT_GEN_THS_ZL_G    0x36
+#define INT_GEN_DUR_G       0x37
+
+///////////////////////////////
+// LSM9DS1 Magneto Registers //
+///////////////////////////////
+#define OFFSET_X_REG_L_M    0x05
+#define OFFSET_X_REG_H_M    0x06
+#define OFFSET_Y_REG_L_M    0x07
+#define OFFSET_Y_REG_H_M    0x08
+#define OFFSET_Z_REG_L_M    0x09
+#define OFFSET_Z_REG_H_M    0x0A
+#define WHO_AM_I_M          0x0F
+#define CTRL_REG1_M         0x20
+#define CTRL_REG2_M         0x21
+#define CTRL_REG3_M         0x22
+#define CTRL_REG4_M         0x23
+#define CTRL_REG5_M         0x24
+#define STATUS_REG_M        0x27
+#define OUT_X_L_M           0x28
+#define OUT_X_H_M           0x29
+#define OUT_Y_L_M           0x2A
+#define OUT_Y_H_M           0x2B
+#define OUT_Z_L_M           0x2C
+#define OUT_Z_H_M           0x2D
+#define INT_CFG_M           0x30
+#define INT_SRC_M           0x30
+#define INT_THS_L_M         0x32
+#define INT_THS_H_M         0x33
+
+////////////////////////////////
+// LSM9DS1 WHO_AM_I Responses //
+////////////////////////////////
+#define WHO_AM_I_AG_RSP     0x68
+#define WHO_AM_I_M_RSP      0x3D
+
+// Possible I2C addresses for the accel/gyro and mag
+#define LSM9DS1_AG_I2C_ADDR(sa0) ((sa0) ? 0xD6 : 0xD4)
+#define LSM9DS1_M_I2C_ADDR(sa1) ((sa1) ? 0x3C : 0x38)
+
+/**
+ * LSM9DS1 Class - driver for the 9 DoF IMU
+ */
+class LSM9DS1
+{
+public:
+
+    /// gyro_scale defines the possible full-scale ranges of the gyroscope:
+    enum gyro_scale
+    {
+        G_SCALE_245DPS = 0x0 << 3,     // 00 << 3: +/- 245 degrees per second
+        G_SCALE_500DPS = 0x1 << 3,     // 01 << 3: +/- 500 dps
+        G_SCALE_2000DPS = 0x3 << 3     // 11 << 3: +/- 2000 dps
+    };
+
+    /// gyro_odr defines all possible data rate/bandwidth combos of the gyro:
+    enum gyro_odr
+    {                               // ODR (Hz) --- Cutoff
+        G_POWER_DOWN     = 0x00,    //  0           0
+        G_ODR_15_BW_0    = 0x20,    //  14.9        0
+        G_ODR_60_BW_16   = 0x40,    //  59.5        16
+        G_ODR_119_BW_14  = 0x60,    //  119         14
+        G_ODR_119_BW_31  = 0x61,    //  119         31
+        G_ODR_238_BW_14  = 0x80,    //  238         14
+        G_ODR_238_BW_29  = 0x81,    //  238         29
+        G_ODR_238_BW_63  = 0x82,    //  238         63
+        G_ODR_238_BW_78  = 0x83,    //  238         78
+        G_ODR_476_BW_21  = 0xA0,    //  476         21
+        G_ODR_476_BW_28  = 0xA1,    //  476         28
+        G_ODR_476_BW_57  = 0xA2,    //  476         57
+        G_ODR_476_BW_100 = 0xA3,    //  476         100
+        G_ODR_952_BW_33  = 0xC0,    //  952         33
+        G_ODR_952_BW_40  = 0xC1,    //  952         40
+        G_ODR_952_BW_58  = 0xC2,    //  952         58
+        G_ODR_952_BW_100 = 0xC3     //  952         100
+    };
+
+    /// accel_scale defines all possible FSR's of the accelerometer:
+    enum accel_scale
+    {
+        A_SCALE_2G, // 00: +/- 2g
+        A_SCALE_16G,// 01: +/- 16g
+        A_SCALE_4G, // 10: +/- 4g
+        A_SCALE_8G  // 11: +/- 8g
+    };
+
+    /// accel_oder defines all possible output data rates of the accelerometer:
+    enum accel_odr
+    {
+        A_POWER_DOWN,   // Power-down mode (0x0)
+        A_ODR_10,       // 10 Hz (0x1)
+        A_ODR_50,       // 50 Hz (0x2)
+        A_ODR_119,      // 119 Hz (0x3)
+        A_ODR_238,      // 238 Hz (0x4)
+        A_ODR_476,      // 476 Hz (0x5)
+        A_ODR_952       // 952 Hz (0x6)
+    };
+
+    // accel_bw defines all possible bandwiths for low-pass filter of the accelerometer:
+    enum accel_bw
+    {
+        A_BW_AUTO_SCALE = 0x0,  // Automatic BW scaling (0x0)
+        A_BW_408 = 0x4,         // 408 Hz (0x4)
+        A_BW_211 = 0x5,         // 211 Hz (0x5)
+        A_BW_105 = 0x6,         // 105 Hz (0x6)
+        A_BW_50 = 0x7           // 50 Hz (0x7)
+    };
+
+    /// mag_scale defines all possible FSR's of the magnetometer:
+    enum mag_scale
+    {
+        M_SCALE_4GS,    // 00: +/- 4Gs
+        M_SCALE_8GS,    // 01: +/- 8Gs
+        M_SCALE_12GS,   // 10: +/- 12Gs
+        M_SCALE_16GS,   // 11: +/- 16Gs
+    };
+
+    /// mag_odr defines all possible output data rates of the magnetometer:
+    enum mag_odr
+    {
+        M_ODR_0625, // 0.625 Hz (0x00)
+        M_ODR_125,  // 1.25 Hz  (0x01)
+        M_ODR_25,   // 2.5 Hz   (0x02)
+        M_ODR_5,    // 5 Hz     (0x03)
+        M_ODR_10,   // 10       (0x04)
+        M_ODR_20,   // 20 Hz    (0x05)
+        M_ODR_40,   // 40 Hz    (0x06)
+        M_ODR_80    // 80 Hz    (0x07)
+    };
+
+    // We'll store the gyro, accel, and magnetometer readings in a series of
+    // public class variables. Each sensor gets three variables -- one for each
+    // axis. Call readGyro(), readAccel(), and readMag() first, before using
+    // these variables!
+    // These values are the RAW signed 16-bit readings from the sensors.
+    int16_t gx_raw, gy_raw, gz_raw; // x, y, and z axis readings of the gyroscope
+    int16_t ax_raw, ay_raw, az_raw; // x, y, and z axis readings of the accelerometer
+    int16_t mx_raw, my_raw, mz_raw; // x, y, and z axis readings of the magnetometer
+    int16_t temperature_raw;
+
+    // floating-point values of scaled data in real-world units
+    float gx, gy, gz;
+    float ax, ay, az;
+    float mx, my, mz;
+    float temperature_c, temperature_f; // temperature in celcius and fahrenheit
+
+    
+    /**  LSM9DS1 -- LSM9DS1 class constructor
+    *  The constructor will set up a handful of private variables, and set the
+    *  communication mode as well.
+    *  Input:
+    *   - interface = Either MODE_SPI or MODE_I2C, whichever you're using
+    *               to talk to the IC.
+    *   - xgAddr = If MODE_I2C, this is the I2C address of the accel/gyro.
+    *               If MODE_SPI, this is the chip select pin of the accel/gyro (CS_A/G)
+    *   - mAddr = If MODE_I2C, this is the I2C address of the mag.
+    *               If MODE_SPI, this is the cs pin of the mag (CS_M)
+    */
+    LSM9DS1(PinName sda, PinName scl, uint8_t xgAddr = LSM9DS1_AG_I2C_ADDR(1), uint8_t mAddr = LSM9DS1_M_I2C_ADDR(1));
+    
+    /**  begin() -- Initialize the gyro, accelerometer, and magnetometer.
+    *  This will set up the scale and output rate of each sensor. It'll also
+    *  "turn on" every sensor and every axis of every sensor.
+    *  Input:
+    *   - gScl = The scale of the gyroscope. This should be a gyro_scale value.
+    *   - aScl = The scale of the accelerometer. Should be a accel_scale value.
+    *   - mScl = The scale of the magnetometer. Should be a mag_scale value.
+    *   - gODR = Output data rate of the gyroscope. gyro_odr value.
+    *   - aODR = Output data rate of the accelerometer. accel_odr value.
+    *   - mODR = Output data rate of the magnetometer. mag_odr value.
+    *  Output: The function will return an unsigned 16-bit value. The most-sig
+    *       bytes of the output are the WHO_AM_I reading of the accel/gyro. The
+    *       least significant two bytes are the WHO_AM_I reading of the mag.
+    *  All parameters have a defaulted value, so you can call just "begin()".
+    *  Default values are FSR's of: +/- 245DPS, 4g, 2Gs; ODRs of 119 Hz for 
+    *  gyro, 119 Hz for accelerometer, 80 Hz for magnetometer.
+    *  Use the return value of this function to verify communication.
+    */
+    uint16_t begin(gyro_scale gScl = G_SCALE_245DPS, 
+                accel_scale aScl = A_SCALE_2G, mag_scale mScl = M_SCALE_4GS,
+                gyro_odr gODR = G_ODR_119_BW_14, accel_odr aODR = A_ODR_119, 
+                mag_odr mODR = M_ODR_80);
+    
+    /**  readGyro() -- Read the gyroscope output registers.
+    *  This function will read all six gyroscope output registers.
+    *  The readings are stored in the class' gx_raw, gy_raw, and gz_raw variables. Read
+    *  those _after_ calling readGyro().
+    */
+    void readGyro();
+    
+    /**  readAccel() -- Read the accelerometer output registers.
+    *  This function will read all six accelerometer output registers.
+    *  The readings are stored in the class' ax_raw, ay_raw, and az_raw variables. Read
+    *  those _after_ calling readAccel().
+    */
+    void readAccel();
+    
+    /**  readMag() -- Read the magnetometer output registers.
+    *  This function will read all six magnetometer output registers.
+    *  The readings are stored in the class' mx_raw, my_raw, and mz_raw variables. Read
+    *  those _after_ calling readMag().
+    */
+    void readMag();
+    
+    /**  readTemp() -- Read the temperature output register.
+    *  This function will read two temperature output registers.
+    *  The combined readings are stored in the class' temperature variables. Read
+    *  those _after_ calling readTemp().
+    */
+    void readTemp();
+    
+    /**  setGyroScale() -- Set the full-scale range of the gyroscope.
+    *  This function can be called to set the scale of the gyroscope to 
+    *  245, 500, or 2000 degrees per second.
+    *  Input:
+    *   - gScl = The desired gyroscope scale. Must be one of three possible
+    *       values from the gyro_scale enum.
+    */
+    void setGyroScale(gyro_scale gScl);
+    
+    /**  setAccelScale() -- Set the full-scale range of the accelerometer.
+    *  This function can be called to set the scale of the accelerometer to
+    *  2, 4, 8, or 16 g's.
+    *  Input:
+    *   - aScl = The desired accelerometer scale. Must be one of five possible
+    *       values from the accel_scale enum.
+    */
+    void setAccelScale(accel_scale aScl);
+    
+    /**  setMagScale() -- Set the full-scale range of the magnetometer.
+    *  This function can be called to set the scale of the magnetometer to
+    *  4, 8, 12, or 16 Gs.
+    *  Input:
+    *   - mScl = The desired magnetometer scale. Must be one of four possible
+    *       values from the mag_scale enum.
+    */
+    void setMagScale(mag_scale mScl);
+    
+    /**  setGyroODR() -- Set the output data rate and bandwidth of the gyroscope
+    *  Input:
+    *   - gRate = The desired output rate and cutoff frequency of the gyro.
+    *       Must be a value from the gyro_odr enum (check above).
+    */
+    void setGyroODR(gyro_odr gRate);
+    
+    /**  setAccelODR() -- Set the output data rate of the accelerometer
+    *  Input:
+    *   - aRate = The desired output rate of the accel.
+    *       Must be a value from the accel_odr enum (check above).
+    */
+    void setAccelODR(accel_odr aRate);
+    
+    /**  setMagODR() -- Set the output data rate of the magnetometer
+    *  Input:
+    *   - mRate = The desired output rate of the mag.
+    *       Must be a value from the mag_odr enum (check above).
+    */
+    void setMagODR(mag_odr mRate);
+
+
+private:    
+    /**  xgAddress and mAddress store the I2C address
+    *  for each sensor.
+    */
+    uint8_t xgAddress, mAddress;
+    
+    // I2C bus
+    I2C i2c;
+
+    /**  gScale, aScale, and mScale store the current scale range for each 
+    *  sensor. Should be updated whenever that value changes.
+    */
+    gyro_scale gScale;
+    accel_scale aScale;
+    mag_scale mScale;
+    
+    /**  gRes, aRes, and mRes store the current resolution for each sensor. 
+    *  Units of these values would be DPS (or g's or Gs's) per ADC tick.
+    *  This value is calculated as (sensor scale) / (2^15).
+    */
+    float gRes, aRes, mRes;
+    
+    /**  initGyro() -- Sets up the gyroscope to begin reading.
+    *  This function steps through all three gyroscope control registers.
+    */
+    void initGyro();
+    
+    /**  initAccel() -- Sets up the accelerometer to begin reading.
+    *  This function steps through all accelerometer related control registers.
+    */
+    void initAccel();
+    
+    /**  initMag() -- Sets up the magnetometer to begin reading.
+    *  This function steps through all magnetometer-related control registers.
+    */
+    void initMag();
+    
+    /**  calcgRes() -- Calculate the resolution of the gyroscope.
+    *  This function will set the value of the gRes variable. gScale must
+    *  be set prior to calling this function.
+    */
+    void calcgRes();
+    
+    /**  calcmRes() -- Calculate the resolution of the magnetometer.
+    *  This function will set the value of the mRes variable. mScale must
+    *  be set prior to calling this function.
+    */
+    void calcmRes();
+    
+    /**  calcaRes() -- Calculate the resolution of the accelerometer.
+    *  This function will set the value of the aRes variable. aScale must
+    *  be set prior to calling this function.
+    */
+    void calcaRes();
+};
+
+#endif // _LSM9DS1_H //

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MX28.lib	Sun Aug 05 13:15:56 2018 +0000
@@ -0,0 +1,1 @@
+https://os.mbed.com/users/alan82914/code/MX28/#ca1e55903d09

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PID.lib	Sun Aug 05 13:15:56 2018 +0000
@@ -0,0 +1,1 @@
+http://developer.mbed.org/teams/LDSC_Robotics_TAs/code/PID/#4df4895863cd

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/encoder.cpp	Sun Aug 05 13:15:56 2018 +0000
@@ -0,0 +1,56 @@
+#include "mbed.h"
+#include "encoder.h"
+
+DigitalOut encoder_cs(D9);
+//SPI spi_encoder(D11, D12, D13); // mosi, miso, sclk
+SPI spi_encoder(D4, D5, D3); // mosi, miso, sclk
+
+unsigned short encoder_value;
+unsigned short angle = 0;
+unsigned short angle_old;
+int angle_dif;
+int a_dif;
+int Angle = 0;
+unsigned short k = 0;
+
+void init_SPI_encoder()
+{
+    spi_encoder.format(16,3);
+    spi_encoder.frequency(1000000); // 1MHz clock rate
+}
+
+void init_encoder()
+{
+    encoder_cs = 1;  // high：disable the device
+}
+
+void angle_measure()
+{
+    encoder_cs = 0; // Select the device by seting chip select low
+    encoder_value = spi_encoder.write(0x00);
+    angle = encoder_value >> 3;
+    encoder_cs = 1; // Deselect the device
+
+    if (k == 0) {
+        Angle = 0;
+        angle_old = angle;
+        k++;
+    } else {
+        angle_dif = angle_count(angle, angle_old);
+        Angle = Angle + angle_dif;
+        angle_old = angle;
+    }
+}
+
+int angle_count(unsigned short now,unsigned short old)
+{
+    a_dif = now - old;
+    if (a_dif > 4096/2) {
+        a_dif = -(4096 - a_dif);
+    } else if (a_dif < -4096/2) {
+        a_dif = 4096 + a_dif;
+    } else {
+        a_dif = a_dif;
+    }
+    return a_dif;
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/encoder.h	Sun Aug 05 13:15:56 2018 +0000
@@ -0,0 +1,23 @@
+#ifndef _ENCODER_H_
+#define _ENCODER_H_
+
+#include "mbed.h"
+
+extern void init_SPI_encoder();
+extern void init_encoder();
+extern void angle_measure();
+extern int angle_count(unsigned short,unsigned short);
+
+extern DigitalOut encoder_cs;
+extern SPI spi_encoder;
+
+extern unsigned short encoder_value;
+extern unsigned short angle;
+extern unsigned short angle_old;
+extern int angle_dif;
+extern int a_dif;
+extern int Angle;
+extern unsigned short k;
+
+
+#endif
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sun Aug 05 13:15:56 2018 +0000
@@ -0,0 +1,209 @@
+#include "mbed.h"
+#include "encoder.h"
+#include "Mx28.h"
+#include "PID.h"
+
+//********************* Dynamxiel ******************************
+#define SERVO_ID 0x01               // ID of which we will set Dynamixel too 
+#define SERVO_ControlPin A2       // Control pin of buffer chip, NOTE: this does not matter becasue we are not using a half to full contorl buffer.
+#define SERVO_SET_Baudrate 1000000  // Baud rate speed which the Dynamixel will be set too (1Mbps)
+#define TxPin A0
+#define RxPin A1
+#define CW_LIMIT_ANGLE 1        // lowest clockwise angle is 1, as when set to 0 it set servo to wheel mode
+#define CCW_LIMIT_ANGLE 4095       // Highest anit-clockwise angle is 0XFFF, as when set to 0 it set servo to wheel mode
+#define PI 3.14159265f
+//***************************************************************
+
+Serial uart(USBTX, USBRX);
+//Serial uart(D10,D2);            // TX : D10     RX : D2           // blueteeth
+DigitalOut LED(A4);            // check if the code is running
+DigitalOut led2(A5);            // check if the code is running interrupt
+uint8_t led2f;
+
+// Timer
+Ticker timer1;
+float ITR_time1 = 10000.0;  // unit：us
+float Ts = ITR_time1/1000000;
+uint8_t flag;
+
+// uart_tx
+union splitter {
+    short j;
+    char C[2];
+    // C[0] is lowbyte of j, C[1] is highbyte of j
+};
+char T[16] = {255,255,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+int i = 0;
+
+// PID
+PID motor_pid(7.2, 0, 0.13, Ts);// 6.4 0.13   7.2 0.13
+float PIDout = 0.0f;
+
+// Dynamixel
+DynamixelClass dynamixelClass(SERVO_SET_Baudrate,SERVO_ControlPin,TxPin,RxPin);
+int servo_cmd;
+int D_angle = 0;
+int D_angle_dif = 0;
+int D_Angle;
+int D_angle_old;
+unsigned short d = 0;
+// Find Torque
+double angle_difference = 0.0;
+float torque_measured = 0.0;
+float ks = 2.6393*2;  //spring constant
+//int angle_dif = 0;
+float torque_ref = 0.0;
+float friction = 0.18f;
+float rate = 0.8;
+//float friction = 0.0f;
+//float check = 0.0f;
+
+// function
+void init_UART();
+void init_TIMER();
+void timer1_ITR();
+void uart_tx();
+
+void init_DYNAMIXEL();
+void D_angle_measure();
+void find_torque();
+
+int main()
+{
+    LED = 1; // darken
+    wait_ms(500);
+    // initial sensor
+    init_SPI_encoder();
+    init_encoder();
+    init_DYNAMIXEL();
+    // initial uart
+    init_UART();
+
+    wait_ms(500);
+
+    led2 = 1;
+    led2f = 0;
+    LED = 0; // lighten
+
+    init_TIMER();
+
+    while(1) {
+        if (flag==1) {
+            led2 = !led2;
+            angle_measure();
+            D_angle_measure();
+            find_torque();
+            motor_pid.Compute(torque_ref, torque_measured);
+            PIDout = motor_pid.output;
+            servo_cmd = PIDout*121.8f;   // 1023/8.4Nm = 121.7857
+
+            if (servo_cmd > 0) {
+                servo_cmd = servo_cmd + ((-torque_ref)*rate+friction)*121.8f;
+                if (servo_cmd >= 1023)
+                    servo_cmd = 1023;
+            } else {
+                servo_cmd = -servo_cmd + 1024 + ((torque_ref)*rate+friction)*121.8f;
+                if (servo_cmd >= 2047)
+                    servo_cmd = 2047;
+            }
+//    dynamixelClass.torque(SERVO_ID, servo_cmd);
+            uart_tx();
+            flag = 0;
+        }
+    }
+}
+
+void init_DYNAMIXEL()
+{
+    dynamixelClass.torqueMode(SERVO_ID, 1);
+    wait_ms(1);
+}
+
+void init_UART()
+{
+    uart.baud(115200);
+}
+
+void init_TIMER()
+{
+    timer1.attach_us(&timer1_ITR, ITR_time1);
+}
+
+void timer1_ITR()
+{
+    flag = 1;
+    if (led2f == 5) {
+
+        led2f = 0;
+    } else {
+        led2f++;
+    }
+}
+
+void uart_tx()
+{
+    splitter s1;
+    splitter s2;
+    splitter s3;
+    splitter s4;
+    splitter s5;
+    splitter s6;
+    splitter s7;
+
+    s1.j = angle;
+    s2.j = Angle;
+    s3.j = 2;
+//    s4.j = 1;
+//    s5.j = 3;
+    s4.j = D_angle;
+    s5.j = D_Angle;
+    s6.j = torque_measured*1000;
+    s7.j = 3;
+
+    T[2] = s1.C[0];
+    T[3] = s1.C[1];
+    T[4] = s2.C[0];
+    T[5] = s2.C[1];
+    T[6] = s3.C[0];
+    T[7] = s3.C[1];
+    T[8] = s4.C[0];
+    T[9] = s4.C[1];
+    T[10] = s5.C[0];
+    T[11] = s5.C[1];
+    T[12] = s6.C[0];
+    T[13] = s6.C[1];
+    T[14] = s7.C[0];
+    T[15] = s7.C[1];
+
+    while(1) {
+        if (uart.writeable() == 1) {
+            uart.putc(T[i]);
+            i++;
+        }
+        if (i >= (sizeof(T)-1)) {
+            i = 0;
+            break;
+        }
+    }
+}
+
+void D_angle_measure()
+{
+    D_angle = dynamixelClass.readPosition(SERVO_ID);
+
+    if (d == 0) {
+        D_Angle = 0;
+        D_angle_old = D_angle;
+        d++;
+    } else {
+        D_angle_dif = D_angle - D_angle_old;
+        D_Angle = D_Angle + D_angle_dif;
+        D_angle_old = D_angle;
+    }
+}
+
+void find_torque()
+{
+    angle_difference = (Angle*3-D_Angle)/4096.0f*2*PI;
+    torque_measured = angle_difference*ks;
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Sun Aug 05 13:15:56 2018 +0000
@@ -0,0 +1,1 @@
+https://os.mbed.com/users/mbed_official/code/mbed/builds/25aea2a3f4e3
\ No newline at end of file