Category: Workshops

Workshop: USB, serial and remote communications with C#

This entry is part 2 of 6 in the series Bioloid Workshop

[Previous post: Workshop: Dynamixel communications with C#]

Bioloid SerialPort2Dynamixel C#

Bioloid SerialPort2Dynamixel C#

SerialPort2Dynamixel

Encapsulating  the SerialPort .Net class offers an easy way to use the serial port and receive Dynamixel Zig messages with the Dynamixel protocol.

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Collaborator classes:

Bioloid SerialPort2Dynamixel C# Collaborators

Bioloid SerialPort2Dynamixel C# Collaborators

– The SerialPort .Net class.

RCDataReader class, which unpack the Dynamixel Zigbee sequence offering the clean data received.

Operations:

The public interface that others classes will use offers principally these operations:

public void setRemoteControlMode(bool on), which sets on or off the reception of data


public void setRemoteControlMode(bool on)
{
if (on)
setReceiveDataMethod(rdDataReader.rawRemoteDataReceived);
else
setReceiveDataMethod(null);
}

public void setReceiveDataMethod(remoteControlDataReceived rcDataReceived), that sets the method that will be called when serial port data is received.

And some basics serial port data operations:

Raspberry Pi - USB2Dynamixel - CM510

Raspberry Pi – USB2Dynamixel – CM510

public bool open(String com, int speed), to open the serial port which name is in the com parameter. Wireless communications and USB ports, as used by Zig or USB2Dynaniel, are also serial ports  (COM1, COM2, … or /ttyUSB0, ttyUSB1).

public void close(), it will do nothing if the port is already closed.

public byte[] query(byte[] buffer, int pos, int wait), send (write) a query and gets (read) the result.

public void rawWrite(byte[] buffer, int pos), well… it will write whatever contains the buffer in the first pos positions

public byte[] rawRead() , read and returns the data received.

Notes:

To avoid concurrency problems all the operations that use the Dynamixel bus are protected with a Mutex object that avoids that two or more concurrent objects use SerialPort2Dynamixel simultaneously entering the same operation or using the same resources, like variables, objects or the Dynamixel bus.

Xevel USB2AX

Xevel USB2AX

USB2AX over USB2DYNAMIXEL

USB2AX over USB2DYNAMIXEL

RCDataReader

Bioloid RCDataReader C#

Bioloid RCDataReader C#

Remote communications

RemoteCommunications

Its responsability is to receive the Dynamixel Zig packets and extract the data.

Collaborator class:

– The ZigSequence enum, with the Dynamixels protocols data sections

RC-100 packet

RC-100 packet

Operations:

Robotis RC-100 remote controller values

Robotis RC-100 remote controller values

public void rawRemoteDataReceived(byte[] rcData), receives the Zigbee data.

public int getValue(), returns the last value received

Workshop: Dynamixel communications with C#

[Next post: Workshop: USB, serial and remote communications with C#]

As I wrote in the previous post, I am not using Robotis Dynamixel SDK USB2Dynamixelbecause it only works with the  USB2Dynamixel, and I need that it also should work with the serial port and with zigbee or bluetooth (really all 4 use the serial connection). Also I want to query sensors connected to the CM-510.

Zigbee device

Zigbee

Using the CM-510 and computer serial port (or USB to serial) connection you are free to use any wired or wireless device. Really there are a lot of possibilities.

We will start connecting to the Dynamixel bus and sending commands and queries. These classes do the work:

DynamixelCommunication

SerialPort2Dynamixel

RCDataReader

But there are other classes that offer to them some additional services, like Configuration, Utils, Hex and several enumeration types.

I will use the Class-Responsability-Collaboration template to present the classes.

DynamixelCommunicationBioloid DynamixelCommunication class C#

The main responsibility of this class is sending commands and queries to any Dynamixel device, including the sensors, sound and other capabilities of the CM-510 controller.

Collaborator classes:

– SerialPort2Dynamixel,  that offers operations to use the serial port encapsulating .Net SerialPort class

– Three enums for easy use and avoid errors, using an specific type is safer that using simple integers.

    public enum AXS1_IRSensor { Left, Center, Right, None };
    public enum AXS1_SoundNote { LA, LA_, SI, DO, DO_, RE }; //Only the first six 
    public enum DynamixelFunction, with all the Dynamixel protocols codes and some that I added for the CM-510.

Configuration class, that reads a file where are stored basic configuration parameters. like:

        private static string ParameterSerialPortName
        private static string ParameterSerialPortBaudRate
        private static string ParameterWaitTime_ms
        private static string ParameterWaitTimeForSensors_ms

Bioloid communications C#

Operations:

The public operations are the interface that other classes will use, like:

short readValue(int id, DynamixelFunction address), reads the value of any AX-12 parameter (or other Dynamixels)

bool sendOrder(int id, DynamixelFunction address, int value), send commands, like position, speed or torque.

And the private that do internal work supporting the public interface, like:

–  static int getReadWordCommand(byte[] buffer, byte id, DynamixelFunction address), create the Dynamixel hexadecimal sequence (FF FF 0F 05 03 1E CB 01 FE)

static short getQueryResult(byte[] res), once the query or command is sent it gets the result.

Let’s see readValue and two other called functions:


public short readValue(int id, DynamixelFunction address)
{
mutex.WaitOne();
short position = -1;

try
{
int size = getReadWordCommand(buffer, (byte)id, address);
byte[] res = serialPort.query(buffer, size, WaitTimeReadSensor);

position = getQueryResult(res);
if (position < 0)
Debug.show("DynamixelCommunication.readValue", position);

}
catch (Exception e)
{
Debug.show("DynamixelCommunication.readValue", e.Message);
}

mutex.ReleaseMutex();

return position;
}

private static int getReadWordCommand(byte[] buffer, byte id, DynamixelFunction address)
{
//OXFF 0XFF ID LENGTH INSTRUCTION PARAMETER1 …PARAMETER N CHECK SUM
int pos = 0;

buffer[pos++] = 0xff;
buffer[pos++] = 0xff;
buffer[pos++] = id;

// bodyLength = 4
buffer[pos++] = 4;

//the instruction, read => 2
buffer[pos++] = 2;

// AX12 register
buffer[pos++] = (byte)address;

//bytes to read
buffer[pos++] = 2;

byte checksum = Utils.checkSumatory(buffer, pos);
buffer[pos++] = checksum;

return pos;
}

private static short getQueryResult(byte[] res)
{
short value = -1;

if (res != null)
{
int length = res.Length;
if (res != null && length > 5 && res[4] == 0)
{
byte l = 0;
byte h = res[5];
if (length > 6)
{
l = res[6];
}

value = Hex.fromHexHLConversionToShort(h, l);
}
}
return value;
}

Notes:

To avoid concurrency problems all the operations that use the Dynamixel bus are protected with a Mutex object that avoids that two or more concurrent objects use DynamixelCommunication simultaneously entering the same operation or using the same resources, like variables, objects or the Dynamixel bus.

All the operations use the same buffer, but being protected with the Mutex object I think that is the better option, although in a previous version I used a very different approach where there were AX12 objects with their own buffer.

[Next post: Workshop: USB, serial and remote communications with C#]

Workshop: Programming a Bioloid robot workbench using C# and C++

This entry is part 1 of 6 in the series Bioloid Workshop

[Next post: Dynamixel communications with C#]

It would be a workshop using C# .Net and C++ with Qt 5. The code presented here is used in this two different robots and boards, a HP 214 Ipaq with Windows Mobile and a Raspberry Pi, using the Robotis CM-510 as the servo and sensors controller:

These will be the first steps, using C# and .Net , here the code and the exe for the Workbench UI:

Bioloid Workbench

Using this enhaced Toss Mode that adds some new functions.  Some of them:

Read more

Start programming CM-5/CM-510 in C (AVR microcontrollers)

This entry is part 1 of 4 in the series Programming CM-5/CM-510

From time to time I receive questions about how to start programming the CM-5/CM-510 with C.

[This post is also in spanish]

I think it’s necessary to have a working knowledge about:

1. C programming

2. CM-5/CM-510 programming

3. Dynamixel protocol

You can find  a lot of information about CM-510 / CM-700  programming at Robotis support website And here you can learn how to create a simple “Hello World” program for CM-5

1. C programming

I think “C Programming for Microcontrollers is a fast and very practical introduction to C and microcontrolers programming, but I’m a not sure if it an easy way to start learning C.If you a want a more structured and deeper introduction to the C programming language, this is a pretty good and free introduction:

C introduction (pdf)

But there are a lot…

C Language Tutorial (html)
How C Programming Works (html)
Several C programming tutorials (html)

and more from Google

2. CM-5/CM-510 programming

From Robotis support website CM-5/CM-510 programming

3. Dynamixel protocol

From Robotis support website Dynamixel actuator

4. Your first step

If you use a CM-510 you will find here at Robotis support site a lot of information, and if you use the CM-5 you will find in this post some useful information and links

Two others great sources of information are:

Robosavvy Bioloid information wiki

Source code of Stuart&Matt library

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