File content as of revision 0:6dc8ac1c7c00:

#include "mbed.h"
#include "LSM9DS0.h"
#include "Mx28.h"
#include <math.h>

// Dynamixel
#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 0x001        // lowest clockwise angle is 1, as when set to 0 it set servo to wheel mode
#define CCW_LIMIT_ANGLE 0xFFF       // Highest anit-clockwise angle is 0XFFF, as when set to 0 it set servo to wheel mode

#define pi 3.14
#define Ts 5                          // sampling time
#define A 20                         // angle
#define f 0.2                        // Hz

unsigned long t = 0;
double deg = 0;
int Pos = 0;
int zero = 190;
char mode = 'a';

Serial pc(SERIAL_TX, SERIAL_RX);

DynamixelClass dynamixelClass(SERVO_SET_Baudrate,SERVO_ControlPin,TxPin,RxPin);
//
DigitalIn mybutton(USER_BUTTON);

// sampling time Lowpass Filter
float T = 0.001;

// Interrupt
Ticker timer1;

// UART
Serial uart_1(D10,D2);            // TX : D10     RX : D2           // serial 1

//
void init_uart(void);
void separate(void);
void uart_send(void);
void init_TIMER(void);
void timer1_interrupt(void);
void change_mode();

float lpf(float input, float output_old, float frequency);

// uart send data
int display[6] = {0,0,0,0,0,0};
char num[14] = {254,255,0,0,0,0,0,0,0,0,0,0,0,0};      // char num[0] , num[1] : 2 start byte

void init_sensor(void);
void read_sensor(void);
void sensor_filter(void);

LSM9DS0 sensor(SPI_MODE, D9, D6);    // SPI_CS1 : D7 , SPI_CS2 : D6

int sensor_flag = 0;                 // sensor initial flag
int sensor_count = 0;

// sensor data
int16_t Gyro_axis_data[3] = {0};     // X, Y, Z axis
int16_t Acce_axis_data[3] = {0};     // X, Y, Z axis

// sensor gain
#define Gyro_gain_x   0        
#define Gyro_gain_y   0           
#define Gyro_gain_z   0            // datasheet : 70 mdeg/digit
#define Acce_gain_x   0                
#define Acce_gain_y   0                  
#define Acce_gain_z   0     

// sensor filter correction data
float Gyro_axis_data_f[3];
float Gyro_axis_data_f_old[3];
float Gyro_scale[3];                          // scale = (data - zero) * gain
float Gyro_axis_zero[3] = {0,0,0};            

float Acce_axis_data_f[3];
float Acce_axis_data_f_old[3];
float Acce_scale[3];                          // scale = (data - zero) * gain
float Acce_axis_zero[3] = {0,0,0};             

int main()
{
    pc.baud(115200);
    dynamixelClass.setMode(SERVO_ID, SERVO, CW_LIMIT_ANGLE, CCW_LIMIT_ANGLE);    // set mode to SERVO and set angle limits
    
    init_uart();
    init_sensor();
    init_TIMER();
    uart_1.attach(&change_mode); 
           
    while(1) 
    {
        pc.printf("%d\n",Pos);
    }   // while(1) end
}

// UART
void init_uart()
{
    uart_1.baud(115200);      // 設定baudrate
}

int i = 0;
void uart_send(void)
{
    // uart send data
    display[0] = Gyro_axis_data[0];
    display[1] = Gyro_axis_data[1];
    display[2] = Gyro_axis_data[2];
    display[3] = Acce_axis_data[0];
    display[4] = Acce_axis_data[1];
    display[5] = Acce_axis_data[2];
    separate();

    int j = 0;
    int k = 1;
    while(k) 
    {
        if(uart_1.writeable()) 
        {            
            uart_1.putc(num[i]);
            i++;
            j++;
        }

        if(j>1)                     // send 2 bytes
        {
            k = 0;
            j = 0;
        }
    }

    if(i>15)
        i = 0;
}

void separate(void)
{
    num[2] = display[0] >> 8;           // HSB(8bit)資料存入陣列
    num[3] = display[0] & 0x00ff;       // LSB(8bit)資料存入陣列
    num[4] = display[1] >> 8;
    num[5] = display[1] & 0x00ff;
    num[6] = display[2] >> 8;
    num[7] = display[2] & 0x00ff;
    num[8] = display[3] >> 8;
    num[9] = display[3] & 0x00ff;
    num[10] = display[4] >> 8;
    num[11] = display[4] & 0x00ff;
    num[12] = display[5] >> 8;
    num[13] = display[5] & 0x00ff;
}

// sensor
void init_sensor(void)
{
    sensor.begin();
}

void read_sensor(void)
{
    // sensor raw data
    Gyro_axis_data[0] = sensor.readRawGyroX();
    Gyro_axis_data[1] = sensor.readRawGyroY();
    Gyro_axis_data[2] = sensor.readRawGyroZ();

    Acce_axis_data[0] = sensor.readRawAccelX();
    Acce_axis_data[1] = sensor.readRawAccelY();
    Acce_axis_data[2] = sensor.readRawAccelZ();
}

void sensor_filter(void)
{
    // gyro filter
    Gyro_axis_data_f[0] = lpf(Gyro_axis_data[0],Gyro_axis_data_f_old[0],18);
    Gyro_axis_data_f_old[0] = Gyro_axis_data_f[0];
    Gyro_axis_data_f[1] = lpf(Gyro_axis_data[1],Gyro_axis_data_f_old[1],18);
    Gyro_axis_data_f_old[1] = Gyro_axis_data_f[1];
    Gyro_axis_data_f[2] = lpf(Gyro_axis_data[2],Gyro_axis_data_f_old[2],18);
    Gyro_axis_data_f_old[2] = Gyro_axis_data_f[2];

    // acce filter
    Acce_axis_data_f[0] = lpf(Acce_axis_data[0],Acce_axis_data_f_old[0],18);
    Acce_axis_data_f_old[0] = Acce_axis_data_f[0];
    Acce_axis_data_f[1] = lpf(Acce_axis_data[1],Acce_axis_data_f_old[1],18);
    Acce_axis_data_f_old[1] = Acce_axis_data_f[1];
    Acce_axis_data_f[2] = lpf(Acce_axis_data[2],Acce_axis_data_f_old[2],18);
    Acce_axis_data_f_old[2] = Acce_axis_data_f[2];

    Gyro_scale[0] = (Gyro_axis_data_f[0]-Gyro_axis_zero[0])*Gyro_gain_x;
    Gyro_scale[1] = (Gyro_axis_data_f[1]-Gyro_axis_zero[1])*Gyro_gain_y;
    Gyro_scale[2] = (Gyro_axis_data_f[2]-Gyro_axis_zero[2])*Gyro_gain_z;

    Acce_scale[0] = ((Acce_axis_data_f[0]-Acce_axis_zero[0]))*Acce_gain_x;
    Acce_scale[1] = ((Acce_axis_data_f[1]-Acce_axis_zero[1]))*Acce_gain_y;
    Acce_scale[2] = ((Acce_axis_data_f[2]-Acce_axis_zero[2]))*Acce_gain_z;
}

// Timer
void init_TIMER(void)
{
    timer1.attach_us(&timer1_interrupt, 10000);//10ms interrupt period (100 Hz)
} 

void timer1_interrupt(void)
{
    // sensor initial start
    if(sensor_flag == 0) {
        sensor_count++;

        if(sensor_count >= 50) {
            sensor_flag  = 1;
            sensor_count = 0;
        }
    } else {
        read_sensor();
        sensor_filter();
        uart_send();
    }

    switch (mode) {
        case 'a':
            deg = zero*4096.0f/360.0f;
            break;
        case 'b':
            deg = (zero + 90)*4096.0f/360.0f;
            break;
        case 'c':
            deg = (zero-A*sin(2*pi*f*t*0.001*Ts))*4096.0f/360.0f;       // 在正負A度搖
            t = t + 1;
            if(t >= 1/(f*0.001*Ts))                              // 2*pi*f*t*0.001*Ts = 2*pi -> t = 1/(f*0.001*T)
                t = 0;
            break;

    }
    
    dynamixelClass.servo(SERVO_ID,deg,0x400);
    Pos = dynamixelClass.readPosition(SERVO_ID);
}

void change_mode()
{
    mode = uart_1.getc();
}

float lpf(float input, float output_old, float frequency)
{
    float output = 0;
    
    output = (output_old + frequency*T*input) / (1 + frequency*T);
    
    return output;
}