Chapter 23
Bioloid

23.1 Introduction

The Bioloid is a a robot construction kit made of servomotors, sensors and frame elements. You can find more information on the manufacturer’s official website at http://www.robotis.com/zbxe/bioloid_en.

Urbi cannot run directly on the Bioloid controller (CM5, CM510). Urbi runs on your computer and talks to the Bioloid controller over serial link (RS232, or wireless depending on your configuration). Urbi can also talk directly to the motor bus if you have an usb2dynamixel.

23.2 Installing Urbi for Bioloid

23.2.1 Flashing the firmware

Urbi for Bioloid is using a custom firmware in the CM-5 controller. You must upload the new firmware in your CM-5 using the procedure below. This operation is reversible.

Download the firmware file from our website at http://www.gostai.com/downloads/urbi-for-bioloid.zip.

• Start the robot terminal software from Robotis (installed with your Bioloid software).
• Make sure your CM-5 batteries are fully charged or that it is plugged to a power supply.
• Connect your CM-5 to the serial port of your computer.
• Turn off your CM-5 (using the red on/off button).
• Maintain the ‘#’ key pressed on your keyboard while turning the CM-5 back on. A message like this one should be displayed:
    SYSTEM O.K. (CM5 boot loader V1.xx)  
    -#######

• Press enter, type load and press enter again. Display should be:
    SYSTEM O.K. (CM5 boot loader V1.xx)  
    -#######  
    -load  
    Write Address: 00000000  
    Ready..

• In the menu, select “Files”, “Transmit file” (Control-T) and select the firmware file you downloaded. After a few seconds, display should turn to:
    Ready..Success  
    (and other information)

23.2.2 Getting Urbi and Urbi for Bioloid

Look at http://www.urbiforge.com/index.php/Robots/Bioloid for up-to-date information on how to download Urbi for Bioloid.

23.3 First steps

23.3.1 Starting up

Connect your CM-5 to the PC and turn it on before starting Urbi.

When you start Urbi, the initialization script in global.u will connect to the CM-5 (edit the file to change the port if required), scan for devices and instantiate them. It will create:

• one bioloid object representing the connexion to the CM5.
• one object per motor (AX12 (Section 23.3.2)) named motorid and motors[id] where id is the motor identifier.
• one object per sensor (AXS1 (Section 23.3.3)) named sensorid and sensors[id] where id is the sensor id (e.g., sensor100, sensors[100]).

Once initialized, do not disconnect any motor that was detected or everything will run very slow.

At this point you might want to give motor names more adapted to your model. Here is an example:

 
do (Global) // Make them available to everyone. 
{ 
  var wheelL = motors[1];  // Left wheel is motor ID 1. 
  var wheelR = motors[2];  // Right wheel is motor ID 2. 
  var headYaw = motors[7]; // Head yaw rotation is motor ID 7. 
};
    

23.3.2 Motor features

All the AX12 features are exposed in urbiscript. The following section lists the main slots with code examples explaining how to use them. You can use Object.localSlotNames and refer to the AX12 documentation for more information.

• val 
  The current motor position when read, the target position when written to.

   
  // Move motor6 to 90 degrees. 
  motor6.val = 90deg; 
  // Move to 0 in 5 seconds. 
  motor6.val = 0 time:5s; 
  // Ticking clock. 
  at (motor6.val > 0) echo("tick") onleave echo("tack"); 
  motor6.val = 0 sin:1s ampli:20deg,
        
  

• cwLimit, ccwLimit 
  Set min and max reachable angles. When they are both equal to 0, the motor is put in continuous rotation mode. In this mode, writing to val has no effect: the motor moves at the speed given by the speed slot.
• speed 
  When read, gives the current rotation speed. When written to, set the speed at which following commands will be executed. In continuous rotation mode, start moving the motor at given speed.

   
  // Set speed to two radians/second. 
  motor6.speed = 2; 
  // Move to 90deg. 
  motor6.val = 90deg; 
  // Switch to continuous rotation mode. 
  motor6.cwLimit = motor6.ccwLimit = 0; 
  // Start moving counter-clockwise at 1 radian/seconds. 
  motor6.speed = 1;
        
  

• torque 
  Current torque the motor is giving.
• load 
  Shut down the motor when 0.

   
  //Turn the motor off if the torque is too high. 
  at(motor6.torque > 5) motor6.load = 0;
        
  

23.3.3 Sensor features

All the AXS1 features are exposed in urbiscript. The following section lists the main slots with code examples explaining how to use them. You can use Object.localSlotNames and refer to the AXS1 documentation for more information.

• IRLeft, IRCenter, IRRight 
  Amount of infrared received by the sensor using the internal emitter. This sensors detect light reflected by objects nearby in the direction of the sensor.
• lightLeft, lightCenter, lightRight 
  Amount of infrared received by the sensor without the emitter. Detects infrared light sources such as incandescent light, candles, ...
• buzzerIndex 
  Play a note when written to.
• buzzerTime 
  Set length of next played note.
• clapCount 
  Number of successive claps detected by the microphone.
• soundVolume 
  Volume of sound received by the microphone.

   
  // The louder the sound, the faster we go. 
  at (sensor100.soundVolume->changed?) 
    motor6.speed = sensor100.soundVolume * 6; 
   
  // Stop after 4 claps 
  at (sensor100.clapCount == 4) 
    motor6.speed = 0;
        
  

• soundVolumeMax 
  Holds maximum sound volume recorded so far. Write 0 to this slot to reset.