Revision 0:03f84c95f73b, committed 2017-02-16

Comitter:

jah128

Date:

Thu Feb 16 20:45:33 2017 +0000

Child:

1:21a24da53b7f

Commit message:

Initial commit

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SerialHalfDuplex.cpp	Thu Feb 16 20:45:33 2017 +0000
@@ -0,0 +1,80 @@
+ /* NB This is part of an older MBED library, included so the older code runs on the
+  * newer MBED library.  There is probably a better implementation.... - jah */
+
+ /* mbed Microcontroller Library
+ * Copyright (c) 2006-2012 ARM Limited
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * NOTE: This is an unsupported legacy untested library.
+ */
+#include "SerialHalfDuplex.h"
+ 
+#if DEVICE_SERIAL
+ 
+#include "pinmap.h"
+#include "serial_api.h"
+#include "gpio_api.h"
+ 
+namespace mbed {
+ 
+SerialHalfDuplex::SerialHalfDuplex(PinName tx, PinName rx, const char *name)
+    : Serial(tx, rx, name) {
+    _txpin = tx;
+    
+    // set as input 
+    gpio_set(_txpin); 
+    pin_mode(_txpin, PullNone); // no pull
+    pin_function(_txpin, 0);    // set as gpio
+}
+ 
+// To transmit a byte in half duplex mode:
+// 1. Disable interrupts, so we don't trigger on loopback byte
+// 2. Set tx pin to UART out
+// 3. Transmit byte as normal
+// 4. Read back byte from looped back tx pin - this both confirms that the
+//    transmit has occurred, and also clears the byte from the buffer.
+// 5. Return pin to input mode
+// 6. Re-enable interrupts
+ 
+int SerialHalfDuplex::_putc(int c) {
+    int retc;
+    
+    // TODO: We should not disable all interrupts
+    __disable_irq();
+    
+    serial_pinout_tx(_txpin);
+    
+    Serial::_putc(c);
+    retc = Serial::getc();       // reading also clears any interrupt
+    
+    pin_function(_txpin, 0);
+    
+    __enable_irq();
+    
+    return retc;
+}
+ 
+int SerialHalfDuplex::_getc(void) {
+    return Serial::_getc();
+}
+ 
+} // End namespace
+ 
+#endif
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SerialHalfDuplex.h	Thu Feb 16 20:45:33 2017 +0000
@@ -0,0 +1,210 @@
+ /* NB This is part of an older MBED library, included so the older code runs on the
+  * newer MBED library.  There is probably a better implementation.... - jah */
+
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2012 ARM Limited
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * NOTE: This is an unsupported legacy untested library.
+ */
+#ifndef MBED_SERIALHALFDUPLEX_H
+#define MBED_SERIALHALFDUPLEX_H
+
+#include "device.h"
+ 
+#if DEVICE_SERIAL
+ 
+#include "Serial.h"
+#include "PinNames.h"
+#include "PeripheralNames.h"
+ 
+namespace mbed {
+ 
+/* Class: SerialHalfDuplex
+ * A serial port (UART) for communication with other devices using  
+ * Half-Duplex, allowing transmit and receive on a single
+ * shared transmit and receive line. Only one end should be transmitting 
+ * at a time.
+ * 
+ * Both the tx and rx pin should be defined, and wired together. 
+ * This is in addition to them being wired to the other serial 
+ * device to allow both read and write functions to operate.
+ *
+ *  Example:
+ *  > // Send a byte to a second HalfDuplex device, and read the response
+ *  >
+ *  > #include "mbed.h"
+ *  >
+ *  > // p9 and p10 should be wired together to form "a"
+ *  > // p28 and p27 should be wired together to form "b"
+ *  > // p9/p10 should be wired to p28/p27 as the Half Duplex connection
+ *  >
+ *  > SerialHalfDuplex a(p9, p10);
+ *  > SerialHalfDuplex b(p28, p27);
+ *  >
+ *  > void b_rx() { // second device response
+ *  >     b.putc(b.getc() + 4);
+ *  > }
+ *  >   
+ *  > int main() {
+ *  >     b.attach(&b_rx);
+ *  >     for(int c = 'A'; c < 'Z'; c++) {
+ *  >         a.putc(c);
+ *  >         printf("sent [%c]\n", c);
+ *  >         wait(0.5);   // b should respond
+ *  >         if(a.readable()) {
+ *  >             printf("received [%c]\n", a.getc());
+ *  >         }
+ *  >     }
+ *  > }
+ * 
+ * For Simplex and Full-Duplex Serial communication, see <Serial>
+ */
+class SerialHalfDuplex : public Serial {
+ 
+public:
+    /* Constructor: SerialHalfDuplex
+     * Create a half-duplex serial port, connected to the specified transmit
+     * and receive pins.
+     *
+     * These pins should be wired together, as well as to the target device
+     *
+     * Variables:
+     *  tx - Transmit pin
+     *  rx - Receive pin
+     */
+    SerialHalfDuplex(PinName tx, PinName rx, const char *name = NULL);
+ 
+#if 0       // Inherited from Serial class, for documentation
+    /* Function: baud
+     *  Set the baud rate of the serial port
+     *
+     * Variables:
+     *  baudrate - The baudrate of the serial port (default = 9600).
+     */
+    void baud(int baudrate);
+ 
+    enum Parity {
+        None = 0
+        , Odd
+        , Even
+        , Forced1
+        , Forced0
+    };
+ 
+    /* Function: format
+     *  Set the transmission format used by the Serial port
+     *
+     * Variables:
+     *  bits - The number of bits in a word (5-8; default = 8)
+     *  parity - The parity used (Serial::None, Serial::Odd, 
+Serial::Even, Serial::Forced1, Serial::Forced0; default = Serial::None)
+     *  stop - The number of stop bits (1 or 2; default = 1)
+     */
+    void format(int bits = 8, Parity parity = Serial::None, int stop_bits 
+= 1);
+ 
+    /* Function: putc
+     *  Write a character
+     *
+     * Variables:
+     *  c - The character to write to the serial port
+     */
+    int putc(int c);
+ 
+    /* Function: getc
+     *  Read a character
+     *
+     * Read a character from the serial port. This call will block
+     * until a character is available. For testing if a character is
+     * available for reading, see <readable>.
+     *
+     * Variables:
+     *  returns - The character read from the serial port
+     */
+    int getc();
+ 
+    /* Function: printf
+     *  Write a formated string
+     *
+     * Variables:
+     *  format - A printf-style format string, followed by the
+     *      variables to use in formating the string.
+     */
+    int printf(const char* format, ...);
+ 
+    /* Function: scanf
+     *  Read a formated string
+     *
+     * Variables:
+     *  format - A scanf-style format string,
+     *      followed by the pointers to variables to store the results.
+     */
+    int scanf(const char* format, ...);
+ 
+    /* Function: readable
+     *  Determine if there is a character available to read
+     *
+     * Variables:
+     *  returns - 1 if there is a character available to read, else 0
+     */
+    int readable();
+ 
+    /* Function: writeable
+     *  Determine if there is space available to write a character
+     *
+     * Variables:
+     *  returns - 1 if there is space to write a character, else 0
+     */
+    int writeable();
+ 
+    /* Function: attach
+     *  Attach a function to call whenever a serial interrupt is generated
+     *
+     * Variables:
+     *  fptr - A pointer to a void function, or 0 to set as none
+     */
+    void attach(void (*fptr)(void));
+ 
+    /* Function: attach
+     *  Attach a member function to call whenever a serial interrupt is generated
+     *
+     * Variables:
+     *  tptr - pointer to the object to call the member function on
+     *  mptr - pointer to the member function to be called
+     */
+    template<typename T>
+    void attach(T* tptr, void (T::*mptr)(void));
+ 
+#endif
+ 
+protected:
+    PinName     _txpin;
+ 
+    virtual int _putc(int c);
+    virtual int _getc(void);
+ 
+}; // End class SerialHalfDuplex
+ 
+} // End namespace
+ 
+#endif
+ 
+#endif
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Feb 16 20:45:33 2017 +0000
@@ -0,0 +1,100 @@
+// Dynamixel Servo Setup Code
+// 
+// Modify the commented lines in main() to setup required servos
+
+#include "servo.h"
+#include "mbed.h"
+#include "SerialHalfDuplex.h"
+
+#define BASE 10
+#define SHOULDER 11
+#define ELBOW 12
+#define WRIST 13
+
+Serial pc(USBTX,USBRX);
+Servo servo(p9,p10);
+
+void scan_for_servos()
+{
+    pc.printf("Scanning for servos at 57600 baud:\n");
+    servo.SetInitBaud(57600,250);
+    for(int i=0;i<254;i++){
+        int model = servo.GetModelNumber(i);
+        if(model == AX12_MODEL) pc.printf("AX-12 found at ID %d",i);
+        if(model == MX28_MODEL) pc.printf("MX-28 found at ID %d",i);
+    }   
+    wait(0.5);
+    pc.printf("\n\nScanning for servos at 1M baud:\n");
+    servo.SetInitBaud(1000000,50);
+    for(int i=0;i<254;i++){
+        int model = servo.GetModelNumber(i);
+        if(model == AX12_MODEL) pc.printf("AX-12 found at ID %d",i);
+        if(model == MX28_MODEL) pc.printf("MX-28 found at ID %d",i);
+    }   
+    while(1);
+}
+
+void initialise_mx28_servo(int current_address, int target_servo)
+{
+    pc.printf("RUNNING SERVO SETUP ROUTINE FOR SERVO %d\n\n",target_servo);
+
+    // MX-28s default to a baud rate of 57600 with delay time of 500us
+    servo.SetInitBaud(57600, 250);
+    int model = servo.GetModelNumber(current_address);
+    if(model != MX28_MODEL) {
+        pc.printf("Error: No MX-28 servo with ID %d found...\n",current_address);
+        while(1);
+    }
+    pc.printf("\n\nSetting up MX-28 servo to ID %d\n",target_servo);
+    servo.SetID(current_address,target_servo);
+    wait(0.25);
+    pc.printf("Getting servo data:\n");
+    servo.DebugData(target_servo);
+    pc.printf("\n\nDone (check messages above to verify status)\n");
+    while(1);
+}
+
+void initialise_ax12_servo(int current_address, int target_servo)
+{
+    pc.printf("RUNNING SERVO SETUP ROUTINE FOR SERVO %d\n\n",target_servo);
+
+    // AX-12s default to a baud rate of 1M with delay time of 100us
+    servo.SetInitBaud(1000000, 50);
+    int model = servo.GetModelNumber(current_address);
+    if(model != AX12_MODEL) {
+        pc.printf("Error: No AX12 servo with ID %d found...\n",current_address);
+        while(1);
+    }
+    pc.printf("\n\nSetting up AX-12 servo to ID %d\n",target_servo);
+    servo.SetID(current_address,target_servo);
+    wait(0.25);
+    pc.printf("Setting return delay time for servo to 500us\n");
+    servo.SetDelayTime(target_servo,250);
+    wait(0.25);
+    pc.printf("Setting baud rate for servo to 57600\n");
+    servo.SetBaud(target_servo,0x22);
+    wait(0.25);
+    pc.printf("Resetting connecting baud rate\n");
+    servo.SetInitBaud(57600, 250);
+    wait(0.25);
+    pc.printf("Getting servo data:\n");
+    servo.DebugData(target_servo);
+    pc.printf("\n\nDone (check messages above to verify status)\n");
+    while(1);
+}
+int main()
+{
+    pc.baud(115200);
+    pc.printf("Dynamixel Servo Setup\n");
+    
+    // To scan for servos, uncomment the following line:
+    //scan_for_servos();
+   
+    // To setup a new MX-28 servo, uncomment the following line and replace first number with current ID and second number with target ID:
+    //initialise_mx28_servo(1,BASE);
+    
+    // To setup a new AX-12 servo, uncomment the following line and replace first number with current ID and second number with target ID:
+    //initialise_ax12_servo(1,WRIST); 
+    
+    pc.printf("Edit the comments in main() to check and program servos.\n");
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Thu Feb 16 20:45:33 2017 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/25aea2a3f4e3
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/servo.cpp	Thu Feb 16 20:45:33 2017 +0000
@@ -0,0 +1,895 @@
+/* University of York Robotics Laboratory Robot Arm Controller Board
+ *
+ * Dynamixel Servo Library for AX-12 and MX-28
+ *
+ * Based on library by Chris Styles (see copyright notice at end of file)
+ *
+ * File: servo.cpp
+ *
+ * (C) Dept. Electronics & Computer Science, University of York
+ * Chris Styles, James Hilder, Alan Millard, Shuhei Miyashita, Homero Elizondo, Jon Timmis
+ *
+ * February 2017, Version 1.0
+ */
+
+#include "servo.h"
+extern Serial pc;
+int delay = RETURN_DELAY;
+char read_timeout_counter = 0;
+Servo::Servo(PinName tx, PinName rx)
+    : _servo(tx,rx)
+{
+    _servo.baud(57600);
+}
+
+void Servo::ClearBuffer()
+{
+    if (_servo.readable()) {
+        pc.printf("\nBuffer error:");
+        while(_servo.readable()) {
+            pc.printf("%c",_servo.getc());
+        }
+        pc.printf("\n");
+    }
+}
+void Servo::ScanForServos ()
+{
+    pc.printf("Scanning for servos...\n");
+    pc.printf("Checking at 57600 baud\n");
+    _servo.baud(57600);
+    delay = 250;
+    int found = 0;
+    for(int k=0; k<2; k++) {
+        if(k==1) {
+            _servo.baud(1000000);
+            pc.printf("\nChecking at 1000000 baud\n");
+        }
+        for(int id = 0; id<254; id++) {
+            if(DEBUG==1)pc.printf("ID %d: ",id);
+            char TxBuf[8];
+            TxBuf[0] = 0xff;
+            TxBuf[1] = 0xff;
+            TxBuf[2] = id;
+            char sum = id + 7;
+            TxBuf[3] = 4;
+            TxBuf[4] = 2;
+            TxBuf[5] = REG_MODEL_NUMBER;
+            TxBuf[6] = 1;
+            TxBuf[7] = 0xFF - sum;
+            for (int i = 0; i<8 ; i++) {
+                _servo.putc(TxBuf[i]);
+            }
+            // Wait for data to transmit
+            int t_delay = 60;
+            wait_us(t_delay);
+            if(_servo.readable()) {
+                pc.printf("ID %d: ",id);
+                // Receive the Status packet 6+ number of bytes read
+                char status[8];
+                for (int i=0; i<(7) ; i++) {
+                    if(!_servo.readable()) {pc.printf("Data error\n");break;}
+                    status[i] = _servo.getc();
+                }
+                if(status[2] == id) {
+                    found ++;
+                    pc.printf(" FOUND [");
+                    char modelnumber = status[5];
+                    switch(modelnumber) {
+                        case (AX12_MODEL):
+                            pc.printf("AX12]\n");
+                            break;
+                        case (MX28_MODEL):
+                            pc.printf("MX28]\n");
+                            break;
+                        default:
+                            pc.printf("UNKNOWN MODEL]\n");
+                            break;
+                    }
+                } else pc.printf(" ID ERROR\n");
+            } else {
+                //pc.printf(" NOT FOUND\n");
+            }
+        }
+    }
+    if(found > 0)pc.printf("\nScan complete [%d servos found].\n",found);
+    else pc.printf("\nScan complete - no servos found.\n");
+    delay = RETURN_DELAY;
+}
+
+
+// Get detailed data for servo
+void Servo::DebugData(int ID)
+{
+    pc.printf("\nGetting Current Data for Servo %d",ID);
+
+
+    char data[49];
+    for(int i=0; i<12; i++) {
+        int offset = i*4;
+        int ErrorCode = read(ID, offset, 4, data+offset);
+        pc.printf(".");
+    }
+    pc.printf("\n");
+
+
+    pc.printf("\nEEPROM VALUES\n");
+
+    int modelnumber = data[0] + (data[1] << 8);
+    pc.printf("Model Number      : %x [",modelnumber);
+    switch(modelnumber) {
+        case (AX12_MODEL):
+            pc.printf("AX12]\n");
+            break;
+        case (MX28_MODEL):
+            pc.printf("MX28]\n");
+            break;
+        default:
+            pc.printf("UNKNOWN]\n");
+            break;
+    }
+    pc.printf("Firmware Version  : %x\n",data[2]);
+    pc.printf("ID                : %x\n",data[3]);
+    int baudrate = 2000000 / (data[4] + 1);
+    //Special high-speed baudrates [for MX28 only]
+    if(data[4] == 250) baudrate = 2250000;
+    if(data[4] == 251) baudrate = 2500000;
+    if(data[4] == 252) baudrate = 3000000;
+    pc.printf("Baud Rate         : %x [%d]\n",data[4],baudrate);
+    pc.printf("Return Delay Time : %x [%duS]\n",data[5],(data[5] * 2));
+    short cw_angle_limit = data[6] + (data[7] << 8);
+    short ccw_angle_limit = data[8] + (data[9] << 8);
+    pc.printf("CW Angle Limit    : %x [%d",cw_angle_limit,cw_angle_limit);
+    if(cw_angle_limit ==0 && ccw_angle_limit == 0)pc.printf(" - Wheel Mode]\n");
+    else {
+        if(cw_angle_limit == 4095 && ccw_angle_limit == 4095)pc.printf(" - Multiturn Mode]\n");
+        else pc.printf("- Joint Mode]\n");
+    }
+    pc.printf("CCW Angle Limit   : %x [%d",ccw_angle_limit,ccw_angle_limit);
+    if(cw_angle_limit ==0 && ccw_angle_limit == 0)pc.printf(" - Wheel Mode]\n");
+    else {
+        if(cw_angle_limit == 4095 && ccw_angle_limit == 4095)pc.printf(" - Multiturn Mode]\n");
+        else pc.printf("- Joint Mode]\n");
+    }
+    //Fill in blanks
+    pc.printf("High Temp Limit   : %x [%dC]\n",data[11],data[11]);
+    pc.printf("Low Voltage Limit : %x [%2.1fV]\n",data[12],(float) (data[12]*0.1f));
+    pc.printf("High Voltage Limit: %x [%2.1fV]\n",data[13],(float) (data[13]*0.1f));
+    short max_torque = data[14] + (data[15] << 8);
+    float pct_max_torque = (float) (max_torque / 10.23f);
+    pc.printf("Preset Max Torque : %x [%3.2f%%]\n",max_torque,pct_max_torque);
+    pc.printf("Status Return Lev.: %x [%d]\n",data[16]);
+    pc.printf("Alarm LED         : %x [%d]\n",data[17]);
+    pc.printf("Alarm Shutdown    : %x [%d]\n",data[18]);
+    short multiturn_offset = data[20] + (data[21] << 8);
+    pc.printf("Multiturn Offset  : %x [%d]\n",multiturn_offset,multiturn_offset);
+    pc.printf("\nRAM VALUES\n");
+    pc.printf("Torque Enable     : %x\n",data[24]);
+    pc.printf("LED               : %x\n",data[25]);
+    pc.printf("D Gain            : %x [%d]\n",data[26],data[26]);
+    pc.printf("I Gain            : %x [%d]\n",data[27],data[27]);
+    pc.printf("P Gain            : %x [%d]\n",data[28],data[28]);
+    short goal_position = data[30] + (data[31] << 8);
+    float gp_degrees = (goal_position - 2048) * 0.087890625;
+    pc.printf("Goal Position     : %x [%d: %3.2f degrees]\n",goal_position,goal_position,gp_degrees);
+    short moving_speed = data[32] + (data[33] << 8);
+    float mv_rpm = moving_speed * 0.114;
+    pc.printf("Moving Speed      : %x [%d: %4.2 rpm]\n",moving_speed,moving_speed,mv_rpm);
+    short c_max_torque = data[34] + (data[35] << 8);
+    float cpct_max_torque = (float) (c_max_torque / 10.23f);
+    pc.printf("Current Max Torque: %x [%3.2f%%]\n",c_max_torque,cpct_max_torque);
+    short present_position = data[36] + (data[37] << 8);
+    float pp_degrees = present_position * 0.088f;
+    pc.printf("Present Position  : %x [%d: %3.2f degrees]\n",present_position,present_position,pp_degrees);
+    short present_speed = data[38] + (data[39] << 8);
+    float p_rpm = present_speed * 0.114;
+    pc.printf("Present Speed     : %x [%d: %4.2 rpm]\n",present_speed,present_speed,p_rpm);
+    short present_load = data[40] + (data[41] << 8);
+    if(present_load < 1024) {
+        float present_loadpct = (1024 - present_load) / 10.23f;
+        pc.printf("Present Load      : %x [%3.2f%% CCW]\n",present_load,present_loadpct);
+    } else {
+        if(present_load > 1024) {
+            float present_loadpct_cw = (present_load - 1024) / 10.23f;
+            pc.printf("Present Load      : %x [%3.2f%% CW]\n",present_load,present_loadpct_cw);
+        } else  pc.printf("Present Load      : %x [NONE]\n",present_load);
+    }
+    pc.printf("Voltage           : %x [%fV]\n",data[42],(data[42] * 0.1f));
+    pc.printf("Temperature       : %x [%dC]\n",data[43],data[43]);
+}
+
+// Set the mode of the servo
+//  0 = Positional (0-300 degrees)
+//  1 = Rotational -1 to 1 speed
+int Servo::SetMode(int ID, int mode)
+{
+    if (mode == 1) { // set CR
+        SetCWLimit(ID, 0);
+        SetCCWLimit(ID, 0);
+        SetCRSpeed(ID, 0.0);
+    } else {
+        SetCWLimit(ID, 0);
+        SetCCWLimit(ID, 300);
+        SetCRSpeed(ID, 0.0);
+    }
+    return(0);
+}
+
+// if flag[0] is set, were blocking
+// if flag[1] is set, we're registering
+// they are mutually exclusive operations
+int Servo::SetGoal(int ID, short goal, int flags)
+{
+
+    char reg_flag = 0;
+    char data[2];
+
+    // set the flag is only the register bit is set in the flag
+    if (flags == 0x2) {
+        reg_flag = 1;
+    }
+    if (DEBUG) {
+        pc.printf("SetGoal to 0x%x ",goal);
+    }
+    
+    data[0] = goal & 0xff; // bottom 8 bits
+    data[1] = goal >> 8;   // top 8 bits
+
+    // write the packet, return the error code
+    int rVal = write(ID, REG_GOAL_POSITION, 2, data, reg_flag);
+
+    if (flags == 1) {
+        // block until it comes to a halt
+        if (DEBUG) pc.printf(" [WAITING]");
+        while (isMoving(ID)) {}
+    }
+    if (DEBUG) pc.printf("\n");
+    return(rVal);
+}
+
+// if flag[0] is set, were blocking
+// if flag[1] is set, we're registering
+// they are mutually exclusive operations
+int Servo::SetGoalDegrees(int ID, int degrees, int flags)
+{
+    short goal = (degrees * 11.377778) + 2048;
+    return SetGoal(ID,goal,flags);
+}
+
+
+// Set continuous rotation speed from -1 to 1
+int Servo::SetCRSpeed(int ID, float speed)
+{
+
+    // bit 10     = direction, 0 = CCW, 1=CW
+    // bits 9-0   = Speed
+    char data[2];
+
+    int goal = (0x3ff * abs(speed));
+
+    // Set direction CW if we have a negative speed
+    if (speed < 0) {
+        goal |= (0x1 << 10);
+    }
+
+    data[0] = goal & 0xff; // bottom 8 bits
+    data[1] = goal >> 8;   // top 8 bits
+
+    // write the packet, return the error code
+    int rVal = write(ID, 0x20, 2, data);
+
+    return(rVal);
+}
+
+
+int Servo::SetCWLimit (int ID, int degrees)
+{
+
+    char data[2];
+
+    // 1023 / 300 * degrees
+    short limit = (1023 * degrees) / 300;
+
+    if (DEBUG) {
+        pc.printf("SetCWLimit to 0x%x\n",limit);
+    }
+
+    data[0] = limit & 0xff; // bottom 8 bits
+    data[1] = limit >> 8;   // top 8 bits
+
+    // write the packet, return the error code
+    return (write(ID, REG_CW_LIMIT, 2, data));
+
+}
+
+int Servo::SetCCWLimit (int ID, int degrees)
+{
+
+    char data[2];
+
+    // 1023 / 300 * degrees
+    short limit = (1023 * degrees) / 300;
+
+    if (DEBUG) {
+        pc.printf("SetCCWLimit to 0x%x\n",limit);
+    }
+
+    data[0] = limit & 0xff; // bottom 8 bits
+    data[1] = limit >> 8;   // top 8 bits
+
+    // write the packet, return the error code
+    return (write(ID, REG_CCW_LIMIT, 2, data));
+}
+
+int Servo::SetTorqueEnable (int ID, int enable)
+{
+    char data[1];
+    data[0]=enable;
+    if (DEBUG) {
+        pc.printf("SetTorqueEnable to %d\n",enable);
+    }
+
+
+    // write the packet, return the error code
+    return (write(ID, REG_TORQUE_ENABLE, 1, data));
+}
+
+int Servo::SetLowVoltageLimit (int ID, char lv_limit)
+{
+
+    char data[1];
+    data[0] = lv_limit;
+    if (DEBUG) {
+        pc.printf("Setting low voltage limit to %2.1f\n",(float) lv_limit / 10.0);
+    }
+    return (write(ID, REG_LOW_VOLTAGE_LIMIT, 1, data));
+}
+
+int Servo::LockEeprom (int ID)
+{
+    char data[1];
+    data[0]=1;
+    if (DEBUG) {
+        pc.printf("Locking EEPROM\n");
+    }
+    return (write(ID, REG_EEPROM_LOCK, 1, data));
+}
+
+int Servo::SetHighVoltageLimit (int ID, char hv_limit)
+{
+
+    char data[1];
+    data[0] = hv_limit;
+    if (DEBUG) {
+        pc.printf("Setting high voltage limit to %2.1f\n",(float) hv_limit / 10.0);
+    }
+    return (write(ID, REG_HIGH_VOLTAGE_LIMIT, 1, data));
+}
+
+int Servo::SetDelayTime (int ID, char delay)
+{
+    char data[1];
+    data[0] = delay;
+    if (DEBUG) {
+        pc.printf("Setting delay time to %dus\n",delay+delay);
+    }
+    return (write(ID, REG_RETURN_DELAY, 1, data));
+}
+
+
+
+int Servo::SetTemperatureLimit (int ID, char temp_limit)
+{
+
+    char data[1];
+    data[0] = temp_limit;
+    if (DEBUG) {
+        pc.printf("Setting temperature limit to %dC\n",temp_limit);
+    }
+    return (write(ID, REG_HIGHTEMP_LIMIT, 1, data));
+}
+
+int Servo::SetID (int CurrentID, int NewID)
+{
+
+    char data[1];
+    data[0] = NewID;
+    if (DEBUG) {
+        pc.printf("Setting ID from 0x%x to 0x%x\n",CurrentID,NewID);
+    }
+    return (write(CurrentID, REG_ID, 1, data));
+
+}
+
+int Servo::SetBaud (int ID, int baud)
+{
+
+    char data[1];
+    data[0] = baud;
+    if (DEBUG) {
+        pc.printf("Setting baud to %d\n",(2000000 / baud));
+    }
+    return (write(ID, REG_BAUDRATE, 1, data));
+
+}
+
+
+// return 1 is the servo is still in flight
+int Servo::isMoving(int ID)
+{
+
+    char data[1];
+    read(ID,REG_MOVING,1,data);
+    return(data[0]);
+}
+
+
+void Servo::trigger(void)
+{
+
+    char TxBuf[16];
+    char sum = 0;
+
+    if (TRIGGER_DEBUG) {
+        pc.printf("\nTriggered\n");
+    }
+
+    // Build the TxPacket first in RAM, then we'll send in one go
+    if (TRIGGER_DEBUG) {
+        pc.printf("\nTrigger Packet\n  Header : 0xFF, 0xFF\n");
+    }
+
+    TxBuf[0] = 0xFF;
+    TxBuf[1] = 0xFF;
+
+    // ID - Broadcast
+    TxBuf[2] = 0xFE;
+    sum += TxBuf[2];
+
+    if (TRIGGER_DEBUG) {
+        pc.printf("  ID : %d\n",TxBuf[2]);
+    }
+
+    // Length
+    TxBuf[3] = 0x02;
+    sum += TxBuf[3];
+    if (TRIGGER_DEBUG) {
+        pc.printf("  Length %d\n",TxBuf[3]);
+    }
+
+    // Instruction - ACTION
+    TxBuf[4] = 0x04;
+    sum += TxBuf[4];
+    if (TRIGGER_DEBUG) {
+        pc.printf("  Instruction 0x%X\n",TxBuf[5]);
+    }
+
+    // Checksum
+    TxBuf[5] = 0xFF - sum;
+    if (TRIGGER_DEBUG) {
+        pc.printf("  Checksum 0x%X\n",TxBuf[5]);
+    }
+
+    // Transmit the packet in one burst with no pausing
+    for (int i = 0; i < 6 ; i++) {
+        _servo.putc(TxBuf[i]);
+    }
+
+    // This is a broadcast packet, so there will be no reply
+
+    return;
+}
+
+int Servo::GetModelNumber(int ID)
+{
+    if (DEBUG) {
+        pc.printf("\nGetModelNumber(%d)",ID);
+    }
+    char data[2];
+    int ErrorCode = read(ID, REG_MODEL_NUMBER, 2, data);
+    int modelnumber = data[0] + (data[1] << 8);
+    return (modelnumber);
+}
+
+float Servo::GetPositionDegrees(int ID)
+{
+    short position = GetPosition(ID);
+    //float angle = (position * 300)/1024;  FOR AX-12
+    float angle = (position - 2048) * 0.087890625;
+
+    return (angle);
+}
+
+short Servo::GetPosition(int ID)
+{
+
+    if (DEBUG) {
+        pc.printf("\nGetPosition(%d)",ID);
+    }
+
+    char data[2];
+
+    int ErrorCode = read(ID, REG_POSITION, 2, data);
+    if (DEBUG) {
+        pc.printf("[EC=%d]",ErrorCode);
+    }
+    short position = data[0] + (data[1] << 8);
+    
+    return (position);
+}
+
+
+float Servo::GetTemp (int ID)
+{
+
+    if (DEBUG) {
+        pc.printf("\nGetTemp(%d)",ID);
+    }
+    char data[1];
+    int ErrorCode = read(ID, REG_TEMP, 1, data);
+    float temp = data[0];
+    return(temp);
+}
+
+short Servo::GetTemperature(int ID)
+{
+    if (DEBUG) {
+        pc.printf("\nGetTemperature(%d)",ID);
+    }
+    char data[1];
+    int ErrorCode = read(ID, REG_TEMP, 1, data);
+    return (short) (data[0]);
+}
+
+float Servo::GetVolts (int ID)
+{
+    if (DEBUG) {
+        pc.printf("\nGetVolts(%d)",ID);
+    }
+    char data[1];
+    int ErrorCode = read(ID, REG_VOLTS, 1, data);
+    float volts = data[0]/10.0;
+    return(volts);
+}
+
+short Servo::GetVoltage(int ID)
+{
+    if (DEBUG) {
+        pc.printf("\nGetVoltage(%d)",ID);
+    }
+    char data[1];
+    int ErrorCode = read(ID, REG_VOLTS, 1, data);
+    return (short) (data[0]);
+}
+
+short Servo::GetLoad(int ID)
+{
+    if (DEBUG) {
+        pc.printf("\nGetLoad(%d)",ID);
+    }
+    char data[2];
+    int ErrorCode = read(ID, REG_LOAD, 2, data);
+    return (short) (data[0] + (data[1]<<8));
+}
+
+short Servo::GetSpeed(int ID)
+{
+    if (DEBUG) {
+        pc.printf("\nGetSpeed(%d)",ID);
+    }
+    char data[2];
+    int ErrorCode = read(ID, REG_SPEED, 2, data);
+    return (short) (data[0] + (data[1]<<8));
+}
+
+int Servo::read(int ID, int start, int bytes, char* data)
+{
+
+    char PacketLength = 0x4;
+    char TxBuf[16];
+    char sum = 0;
+    char Status[16];
+
+    Status[4] = 0xFE; // return code
+
+    if (READ_DEBUG) {
+        pc.printf("\nread(%d,0x%x,%d,data)\n",ID,start,bytes);
+    }
+
+    // Build the TxPacket first in RAM, then we'll send in one go
+    if (READ_DEBUG) {
+        pc.printf("\nInstruction Packet\n  Header : 0xFF, 0xFF\n");
+    }
+
+    TxBuf[0] = 0xff;
+    TxBuf[1] = 0xff;
+
+    // ID
+    TxBuf[2] = ID;
+    sum += TxBuf[2];
+    if (READ_DEBUG) {
+        pc.printf("  ID : %d\n",TxBuf[2]);
+    }
+
+    // Packet Length
+    TxBuf[3] = PacketLength;    // Length = 4 ; 2 + 1 (start) = 1 (bytes)
+    sum += TxBuf[3];            // Accululate the packet sum
+    if (READ_DEBUG) {
+        pc.printf("  Length : 0x%x\n",TxBuf[3]);
+    }
+
+    // Instruction - Read
+    TxBuf[4] = 0x2;
+    sum += TxBuf[4];
+    if (READ_DEBUG) {
+        pc.printf("  Instruction : 0x%x\n",TxBuf[4]);
+    }
+
+    // Start Address
+    TxBuf[5] = start;
+    sum += TxBuf[5];
+    if (READ_DEBUG) {
+        pc.printf("  Start Address : 0x%x\n",TxBuf[5]);
+    }
+
+    // Bytes to read
+    TxBuf[6] = bytes;
+    sum += TxBuf[6];
+    if (READ_DEBUG) {
+        pc.printf("  No bytes : 0x%x\n",TxBuf[6]);
+    }
+
+    // Checksum
+    TxBuf[7] = 0xFF - sum;
+    if (READ_DEBUG) {
+        pc.printf("  Checksum : 0x%x\n",TxBuf[7]);
+    }
+
+    // Transmit the packet in one burst with no pausing
+    for (int i = 0; i<8 ; i++) {
+        _servo.putc(TxBuf[i]);
+    }
+
+    // Wait for data to transmit
+    wait_us(60); //was 60
+
+
+    // Skip if the read was to the broadcast address
+    if (ID != 0xFE) {
+        int timedout = 0;
+        int timeout_count = 0;
+        while(!_servo.readable()) {
+            timeout_count++;
+            if(timeout_count % 10000 == 0) {
+                timedout=1;
+                break;
+            }
+        }
+        if(timedout==1) {
+            read_timeout_counter++;
+            if(DEBUG)pc.printf("  Read timed out [%d of %d]\n",read_timeout_counter,READ_TIMEOUT_LIMIT);
+            if(read_timeout_counter >= READ_TIMEOUT_LIMIT){
+                read_timeout_counter = 0;
+                return 255;
+            }
+            return read(ID,start,bytes,data);
+        } else {
+            read_timeout_counter = 0;
+            // Receive the Status packet 6+ number of bytes read
+            for (int i=0; i<(6+bytes) ; i++) {
+                Status[i] = _servo.getc();
+            }
+
+            // Copy the data from Status into data for return
+            for (int i=0; i < Status[3]-2 ; i++) {
+                data[i] = Status[5+i];
+            }
+
+            if (READ_DEBUG) {
+                pc.printf("\nStatus Packet\n");
+                pc.printf("  Header : 0x%x\n",Status[0]);
+                pc.printf("  Header : 0x%x\n",Status[1]);
+                pc.printf("  ID : 0x%x\n",Status[2]);
+                pc.printf("  Length : 0x%x\n",Status[3]);
+                pc.printf("  Error Code : 0x%x\n",Status[4]);
+
+                for (int i=0; i < Status[3]-2 ; i++) {
+                    pc.printf("  Data : 0x%x\n",Status[5+i]);
+                }
+
+                pc.printf("  Checksum : 0x%x\n",Status[5+(Status[3]-2)]);
+            }
+
+        } // if (ID!=0xFE)
+        wait_us(5);
+    }
+    return(Status[4]);
+}
+
+
+int Servo:: write(int ID, int start, int bytes, char* data, int flag)
+{
+// 0xff, 0xff, ID, Length, Intruction(write), Address, Param(s), Checksum
+
+    char TxBuf[16];
+    char sum = 0;
+    char Status[6];
+
+    if (WRITE_DEBUG) {
+        pc.printf("\nwrite(%d,0x%x,%d,data,%d)\n",ID,start,bytes,flag);
+    }
+
+    // Build the TxPacket first in RAM, then we'll send in one go
+    if (WRITE_DEBUG) {
+        pc.printf("\nInstruction Packet\n  Header : 0xFF, 0xFF\n");
+    }
+
+    TxBuf[0] = 0xff;
+    TxBuf[1] = 0xff;
+
+    // ID
+    TxBuf[2] = ID;
+    sum += TxBuf[2];
+
+    if (WRITE_DEBUG) {
+        pc.printf("  ID : %d\n",TxBuf[2]);
+    }
+
+    // packet Length
+    TxBuf[3] = 3+bytes;
+    sum += TxBuf[3];
+
+    if (WRITE_DEBUG) {
+        pc.printf("  Length : %d\n",TxBuf[3]);
+    }
+
+    // Instruction
+    if (flag == 1) {
+        TxBuf[4]=0x04;
+        sum += TxBuf[4];
+    } else {
+        TxBuf[4]=0x03;
+        sum += TxBuf[4];
+    }
+
+    if (WRITE_DEBUG) {
+        pc.printf("  Instruction : 0x%x\n",TxBuf[4]);
+    }
+
+    // Start Address
+    TxBuf[5] = start;
+    sum += TxBuf[5];
+    if (WRITE_DEBUG) {
+        pc.printf("  Start : 0x%x\n",TxBuf[5]);
+    }
+
+    // data
+    for (char i=0; i<bytes ; i++) {
+        TxBuf[6+i] = data[i];
+        sum += TxBuf[6+i];
+        if (WRITE_DEBUG) {
+            pc.printf("  Data : 0x%x\n",TxBuf[6+i]);
+        }
+    }
+
+    // checksum
+    TxBuf[6+bytes] = 0xFF - sum;
+    if (WRITE_DEBUG) {
+        pc.printf("  Checksum : 0x%x\n",TxBuf[6+bytes]);
+    }
+
+    // Transmit the packet in one burst with no pausing
+    for (int i = 0; i < (7 + bytes) ; i++) {
+        _servo.putc(TxBuf[i]);
+    }
+
+    // Wait for data to transmit
+    wait_us(60);
+
+    // make sure we have a valid return
+    Status[4]=0x00;
+
+    // we'll only get a reply if it was not broadcast
+    if (ID!=0xFE) {
+        int timedout = 0;
+        int timeout_count = 0;
+        while(!_servo.readable()) {
+            timeout_count++;
+            if(timeout_count % 10000 == 0) {
+                timedout=1;
+                break;
+            }
+        }
+        if(timedout==1) {
+            read_timeout_counter++;
+            if(DEBUG)pc.printf("  Write ack. timed out [%d of %d]\n",read_timeout_counter,READ_TIMEOUT_LIMIT);
+            if(read_timeout_counter >= READ_TIMEOUT_LIMIT){
+                read_timeout_counter = 0;
+                return 255;
+            }
+            return write(ID,start,bytes,data,flag);
+        } else {
+            read_timeout_counter = 0;
+            // response is always 6 bytes
+            // 0xFF, 0xFF, ID, Length Error, Param(s) Checksum
+            for (int i=0; i < 6 ; i++) {
+                Status[i] = _servo.getc();
+            }
+        }
+        // Build the TxPacket first in RAM, then we'll send in one go
+        if (WRITE_DEBUG) {
+            pc.printf("\nStatus Packet\n  Header : 0x%X, 0x%X\n",Status[0],Status[1]);
+            pc.printf("  ID : %d\n",Status[2]);
+            pc.printf("  Length : %d\n",Status[3]);
+            pc.printf("  Error : 0x%x\n",Status[4]);
+            pc.printf("  Checksum : 0x%x\n",Status[5]);
+        }
+
+
+    }
+
+    return(Status[4]); // return error code
+}
+
+//Set the baud rate for serial connection to something other than default(1000000)
+void Servo::SetInitBaud(int baud, int delaytime)
+{
+    pc.printf("Setting serial baud rate to %d\n",baud);
+    _servo.baud(baud);
+    delay = delaytime;
+}
+
+/* Additional copyright notice */
+
+/*
+ * Copyright 2017 University of York
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and limitations under the License.
+ *
+ */
+
+/*
+ * Copyright (c) 2010, Chris Styles (http://mbed.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+/*
+ * Copyright (c) 2010, Chris Styles (http://mbed.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/servo.h	Thu Feb 16 20:45:33 2017 +0000
@@ -0,0 +1,344 @@
+/* University of York Robotics Laboratory Robot Arm Controller Board
+ *
+ * Dynamixel Servo Library for AX-12 and MX-28
+ *
+ * Based on library by Chris Styles (see copyright notice at end of file)
+ *
+ * File: servo.cpp
+ *
+ * (C) Dept. Electronics & Computer Science, University of York
+ * Chris Styles, James Hilder, Alan Millard, Shuhei Miyashita, Homero Elizondo, Jon Timmis
+ *
+ * February 2017, Version 1.0
+ */
+ 
+// NOTE:
+// When communicating with 'new' servos the are defaulted to ID 1
+// Make sure only one such servo is connected at one time
+// Also note that this library defaults to 57600 serial comms
+// The MX-28s are defaulted to communicate at this speed but the AX-12s are not (1Mbaud)
+// Use SetInitBaud(57600) to override the default and then change baud rate when setting up MX-28s
+
+#ifndef SERVO_H
+#define SERVO_H
+
+#include "mbed.h"
+#include "SerialHalfDuplex.h"
+
+#define WRITE_DEBUG 0
+#define READ_DEBUG 0
+#define TRIGGER_DEBUG 0
+#define DEBUG 0
+
+// Number of times to retry a read\write operation if read times out
+#define READ_TIMEOUT_LIMIT 3
+
+#define LOW_VOLTAGE_LIMIT 90
+#define HIGH_VOLTAGE_LIMIT 140
+#define HIGH_TEMPERATURE_LIMIT 70
+
+#define AX12_MODEL 0x0C
+#define MX28_MODEL 0x1D
+
+#define RETURN_DELAY 250
+
+#define REG_MODEL_NUMBER 0x00
+#define REG_FIRMWARE_VERSION 0x02
+#define REG_ID 0x03
+#define REG_BAUDRATE 0x04
+#define REG_RETURN_DELAY 0x05
+#define REG_CW_LIMIT 0x06
+#define REG_CCW_LIMIT 0x08
+#define REG_HIGHTEMP_LIMIT 0x0B
+#define REG_LOW_VOLTAGE_LIMIT 0x0C
+#define REG_HIGH_VOLTAGE_LIMIT 0x0D
+#define REG_MAX_TORQUE 0x0E
+#define REG_TORQUE_ENABLE 0x18
+#define REG_GOAL_POSITION 0x1E
+#define REG_MOVING_SPEED 0x20
+#define REG_VOLTS 0x2A
+#define REG_TEMP 0x2B
+#define REG_SPEED 0x26
+#define REG_LOAD 0x28
+#define REG_MOVING 0x2E
+#define REG_POSITION 0x24
+#define REG_EEPROM_LOCK 0x2F
+
+#define MODE_POSITION  0
+#define MODE_ROTATION  1
+
+#define CW 1
+#define CCW 0
+
+extern Serial data;
+
+class Servo {
+
+public:
+
+    /** Create a Dynamixel servo controller object connected to the specified serial port, with the specified ID
+     *
+     * @param pin tx pin
+     * @param pin rx pin 
+     */
+    Servo(PinName tx, PinName rx);
+
+    void ClearBuffer(void);
+
+    void ScanForServos(void);
+
+
+    /** Prints (over PC serial) a detailed set of data for the servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     */
+    void DebugData(int ID);
+
+    /** Set the mode of the servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @param mode
+     *    0 = Positional, default
+     *    1 = Continuous rotation
+     */
+    int SetMode(int ID,  int mode);
+
+    /** Set goal angle, in positional mode
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @param goal 0-4095
+     * @param flags, defaults to 0
+     *    flags[0] = blocking, return when goal position reached 
+     *    flags[1] = register, activate with a broadcast trigger
+     *
+     */
+    int SetGoal(int ID, short goal, int flags = 0);
+
+    /** Set goal angle in integer degrees, in positional mode
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @param degrees 0-300
+     * @param flags, defaults to 0
+     *    flags[0] = blocking, return when goal position reached 
+     *    flags[1] = register, activate with a broadcast trigger
+     *
+     */
+    int SetGoalDegrees(int ID, int degrees, int flags = 0);
+
+
+    /** Set the speed of the servo in continuous rotation mode
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @param speed, -1.0 to 1.0
+     *   -1.0 = full speed counter clock wise
+     *    1.0 = full speed clock wise
+     */
+    int SetCRSpeed(int ID, float speed);
+
+
+    /** Set the clockwise limit of the servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @param degrees, 0-300
+     */
+    int SetCWLimit(int ID, int degrees);
+    
+    /** Set the counter-clockwise limit of the servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @param degrees, 0-300
+     */
+    int SetCCWLimit(int ID, int degrees);
+
+    /** Enable or disable the torque hold of the servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @param enable, 0=disable (floppy) 1=enable (hold)
+     */
+     int SetTorqueEnable (int ID, int enable);
+
+
+    /** Change the low voltage limit of a servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @param lv_limit, 0-254
+     *
+     * voltage = lv_limit / 10
+     */
+    int SetLowVoltageLimit (int ID, char lv_limit);
+    
+    /** Lock the EEPROM area of a servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     */
+    int LockEeprom(int ID);
+    
+    /** Change the high voltage limit of a servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @param hv_limit, 0-254
+     *
+     * voltage = hv_limit / 10
+     */
+    int SetHighVoltageLimit (int ID, char hv_limit);
+    
+    /** Change the delay time of a servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @param delay, 0-254 C
+     *
+     */
+    int SetDelayTime (int ID, char delay);
+    
+    /** Change the high temperature limit of a servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @param temp_limit, 0-254 C
+     *
+     */
+    int SetTemperatureLimit (int ID, char temp_limit);
+    
+    /** Change the ID of a servo
+     *
+     * @param CurentID 1-255
+     * @param NewID 1-255
+     *
+     * If a servo ID is not know, the broadcast address of 0 can be used for CurrentID.
+     * In this situation, only one servo should be connected to the bus
+     */
+    int SetID(int CurrentID, int NewID);
+
+    /** Change the baud of a servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @param baud, 0-252
+     *
+     * baudrate = 2000000/baud (with special cases 250=2.25Mbps, 251=2.5Mbps and 252=3Mbps on MX-28 only)
+     */
+    int SetBaud (int ID, int baud);
+
+    /** Poll to see if the servo is moving
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @returns true is the servo is moving
+     */
+    int isMoving(int ID);
+
+    /** Send the broadcast "trigger" command, to activate any outstanding registered commands
+     */
+    void trigger(void);
+
+    /** Read the model number of the servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @returns int matching defined model number
+     */
+    int GetModelNumber(int ID);
+
+    /** Read the current angle of the servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @returns float in the range 0.0-300.0
+     */
+    float GetPositionDegrees(int ID);
+
+
+    /** Read the raw angle reading of the servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @returns short in the range 0 - 4095 for MX-28
+     */
+    short GetPosition(int ID);
+
+
+    /** Read the temperature of the servo
+     *
+     * @returns float temperature 
+     */
+    float GetTemp(int ID);
+
+    /** Read the supply voltage of the servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @returns short voltage * 10
+     */
+    short GetVoltage(int ID) ;
+    
+    /** Read the supply voltage of the servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @returns float voltage
+     */
+    float GetVolts(int ID);
+    
+    /** Read the temperature of the servo
+     *
+     * @returns short temperature 
+     */
+    short GetTemperature(int ID);
+
+    /** Read the torque load of the servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @returns short load, range 0-2048, 0 is 100% CCW, 1024 is zero and 2048 is 100% CW
+     */
+    short GetLoad(int ID) ;
+    
+    /** Read the speed of the servo
+     *
+     * @param ID, the Bus ID of the servo 1-255 
+     * @returns short speed
+     */
+    short GetSpeed(int ID) ;
+        
+     /** Change the internal baud rate to something other than 1000000 (note MX-28s default to 57600)
+     *
+     * @param baud, the baud rate to set
+     * @param delaytime, the delay time to set (x2 us)
+     */
+    void SetInitBaud(int baud, int delaytime);
+    
+
+private :
+    SerialHalfDuplex _servo;
+    int read(int ID, int start, int length, char* data);
+    int write(int ID, int start, int length, char* data, int flag=0);
+
+};
+
+
+
+#endif
+
+/*
+ * Copyright 2017 University of York
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and limitations under the License.
+ *
+ */
+
+/*
+ * Copyright (c) 2010, Chris Styles (http://mbed.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
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