A humanoid built using the Bioloid Comprehensive kit.

All robot construction kits let you “invent” your own robotic creations. Bioloid is not an exception. However, every one of these kits have their own strengths and weaknesses. The strong side of this kit is the possibility of building and programming limbed robots.

Wow, I kind of managed to tell all I wanted in one paragraph! OK, I’ll try to expand the idea a bit so you don’t feel disappointed. So, you can make limbed robots quite easily with this kit, as far as robot building can be easy, that is.

The software, the controller as well as servos and the body parts are all designed specifically for this purpose. I’ll try to describe the main benefits of each of them as well as give you a short insight on available Bioloid kits.

The controllers

The controller found in Bioloid kits is the atmega128-based CM-5. The CM-5 has some programmable buttons and LEDs, as well as a few status LEDs that indicate its current mode of operation. It can be connected to a PC using a serial cable.

There are 4 bus connectors – one on top and bottom of the controller and two on each of the sides. These are used to connect the Dynamixel units – motors and sensors. I hear you shouting out loud now, “Hey, only 4 I/O ports!?” Be assured – you can connect more than 4 devices to this controller.

Firstly, you can have more bus connections if needed using an expansion unit. But even more important is that you can connect multiple Dynamixel units (motors and sensors) to one port by connecting them in a daisy chain. As I understand, you could actually connect all motors needed to a controller through a single port, as long as wiring considerations allow it.

CM-5 controller

There are other things that should be noted when talking about the CM-5. The microcontroller’s encasement houses the battery that provides power to both – the controller and the Dynamixel units. Also, wireless communication is possible through a ZigBee interface using a separate module.


CM-510 is the next version of the CM-5. It has twice as much memory as it is based on Atmega 2561, it has 5 Dynamixel bus ports and as an addition – 6 analogue I/O ports, so it is possible to connect other sensors to this controller as well.

Both – CM-5 and CM-510 are intended to control AX series Dynamixel units (these come in Bioloid kits). In case you have some AX series actuators and you feel that these controllers are a bit restrictive to you, there are solutions from other manufacturers for advanced users, such as the arbotiX Robocontroller.

Until now, I’ve spoken only about AX series dynamixel units, as these are included in the kits. However, there are other dynamixel series as well, such as DX and RX; there are controllers that allow you to control these as well, such as the CM-2 controller board. Or, you can design one by yourself.


I suppose, you have quite a few questions by now. Something like, “What really is Dynamixel?”, “What’s so good or unique about it?” and so on. OK, I’ll try to shed some light on it. Basically, Dynamixel is a brand name that describes a line of robot actuators (and some sensor units) made by Robotis – the manufacturer of the Bioloid kit.

As Robotis puts it, Dynamixel is a precision DC motor, a speed reducer, a controller, a driver and network functionality integrated into one module. So, you can control its location and speed with a 1024 step resolution, read its current position, speed, torque, supplied voltage and other parameters.

It’s also available to set marginal levels of internal temperature, torque and other parameters, at which to shut down. Another really handy feature that separates Dynamixels from other servos is the possibility to switch it between angular and continuous rotation modes in software.

Dynamixels’ network functionality is another strong point. So, you can connect these servos (if I can use this humble designation) in a serial network (TTL, RS485 or CAN, depending of the model), thus controlling many servos through a single bus output on the controller. This is why I said, that Bioloid is especially suitable to create limbed robots.

This video is a good example of this network functionality:

As you see, Dynamixel actuators are quite strong in every sense of this word. As I mentioned above, Dynamixels included in Bioloid kit are AX series Dynamixels. AX-12+ is a motor and AX-S1 is a sensor module. Both are compatible with controllers and software provided with the kit.

I should say some words about the AX-S1 module. It is quite unique as it is not an actuator as other Dynamixels but a sensor unit instead. So, there are an IrDA receiver, three infrared sensors, a microphone and a sounder bundled in this module.

The idea is quite useful, right? Well, Robotis obviously though the same. So, in case you think you could use Dynamixels in your project, but you need different torque, speed, etc, there are other series as well. RX, DX, EX – different actuators with different torque levels.

If you own a controller from Bioloid, you should take into consideration, that those controllers are compatible only with AX series Dynamixels. To use other Dynamixels you can use CM-2, CM-700 or a microcontroller of your choice. Obviously, these are advanced actuators, so you should have some controller coding knowledge prior to use them.

Also, it is possible to control Dynamixels through a PC using a USB2Dynamixel module from Robotis. This is a great way if you want to make some kind of inverse kinematics project (such as a robot arm) and you’re OK with controlling it via a PC.

The software

I suppose you may feel a bit overwhelmed by now and it may seem a bit too complicated if you’re not an advanced robot builder. If you are… then what are you still doing here? Go build a C-3PO, maybe you can use some Dynamixels there! OK, just kidding, although… Why not?

I’ll get back to the point. If you think this is too complicated for you, please don’t. The software provided with Bioloid is quite easy to understand and makes creation of complicated limbed robots quite accessible even if you don’t have prior experience in this field.

At the moment I’m writing this it’s kind of a crossroad between what it was and what it will be in near future. So, the “old” software is a bundle of two utilities – Behavior Control Program and Motion Editor. The new software is RoboPlus.

BCP and Motion Editor

Behavior Control Program lets you program the CM-5 controller using functionality similar to drag and drop environments. With this software you can tell your controller what to do, for example – if sound is detected, turn on a LED, set the speed of a Dynamixel, move forward, etc.

Motion Editor is used to define what exactly “move forward” means in case of a limbed robot. As you can understand, in order to walk, a robot has to change its motors’ angular positions in a correct sequence. This is quite troublesome if you have to figure it out and write every line of code by yourself.

This is where Motion Editor comes in. With this software you can “record” your robot’s movements as you wish. Of course, this is not limited to walking. As you can record movements as you wish, you could easily make a martial arts or some other sequence as well.

The software is freeware, so it can be installed on many computers legally. This is useful if Bioloid is used in an educational environment – there are no additional software related expenses that should be covered.


RoboPlus Motion

RoboPlus is the next generation software for Bioloid kits, Ollo kits and other Robotis creations. The basic idea is the same as in BCP and Motion Editor. So, there are numerous components in RoboPlus – RoboPlus Task, RoboPlus Motion and RoboPlus Manager. For advanced users there is RobotPlus terminal and Dynamixel wizard as well.


RoboPlus Task is a replacement for Behaviour Control Program. The drag and drop functionality is preserved, but the look of the code is different. It looks like a written C-style program, only you don’t actually write the code. This is somewhat similar to EasyC for Vex.

RoboPlus Motion, on the other hand, replaces Motion Editor. Although the interaction between these two components is similar to that of BCP and Motion Editor, the functionality of this interaction as well as of each separate component is heavily improved.

RoboPlus Manager handles the firmware updates and controller testing. You can use RoboPlus Terminal to directly communicate with the controller. The Dynamixel Wizard, on the other hand, can be used to manage your Dynamixels directly using a PC.

Although RoboPlus at the moment is being shipped only with Bioloid Premium kits, which have CM-510 controller, CM-5 is also supported. So, it is possible to program existing Bioloid kits with it. I suppose in future, it will be shipped with other Bioloid kits as well.Apart from these two controllers, others controllers are supported as well. Such as – Ollo’s CM-100 and the advanced CM-700.

The kits

I suppose you would like to know what kind of Bioloid kits there are. Sure, if you’re an advanced robot builder and you have a project in mind where you could use the benefits of Dynamixel, you don’t really need a kit; you can buy exactly what you need for your project.

On the other hand, Bioloid kits are great if you don’t have a specific project in mind, or you want to get started with robot building. Also, these kits could be suitable for educational institutions or even some research projects.

Bioloid Beginner, Comprehensive and Expert kits

So, the Beginner kit is intended as an introduction to the Bioloid system. It has a CM-5 controller, five Dynamixels – four AX-12+ servos and one AX-S1 sensor module, a rechargeable NiMh battery pack, a serial cable, a manual, a power supply and a software package that includes Behavior Control Program and Motion Editor.

As you can understand, the Beginner kit can be a bit restrictive with its four servos. Of course, you can build a 4 DOF robot arm, a simple humanoid and other relatively simple creations using the Beginner kit, but chances are you’ll need more than that if you have something serious in mind.

This is where the Comprehensive kit comes in. It’s the same as Beginner kit, only this time there are eighteen AX-12+ servos instead of four and a Comprehensive frame set to put it all together. I think, eighteen servos are enough to make a martial artist. In fact, instructions on how to create 26 different robots are provided. So this is the most obvious choice for most robotics enthusiasts.

The Expert kit on the other hand has two CM-5 controllers twelve AX-12+ servos, three AX-S1 sensor modules, two NiMh battery packs, two Comprehensive frame sets, one Zig-100 wireless communication module set, one Zig2Serial adapter, one USB2Dynamixel adapter, one wireless camera set, manuals, cables and a software package. This kit is designed for educational or research use.

Bioloid Premium kit

This kit is the next generation of these kits. It comes as a replacement for the Comprehensive kit. So it has a CM-510 controller, eighteen AX-12+ actuators, a LiPo rechargeable battery, a 2-axis Gyro sensor (balance sensor), a distance measurement sensor and two IR sensors.

As you can see, this kit features more separate sensors instead of one sensor module as in Comprehensive kit. This makes it more flexible. Also it should be noted that this kit ships with the new RoboPlus software package. Oh, it has head and chest covers to make humanoids made with this kit prettier.

In case you already own a Comprehensive kit don’t rush it. There is a Comprehensive – Premium upgrade package available. Why choose Premium over Comprehensive? More powerful controller, more flexibility, new software, a LiPo battery pack and a pretty head cover are a few reasons.

Oh yeah, it can surf-ride as well:

As always, I hope you found this article interesting and I hope I managed to answer at least some of your questions about Robotis, Bioloid and Dynamixel. If you are interested in robot construction kits, you may find my article on robot construction kits interesting as well.

In case you want one, Trossen robotics (aff link – read ad policy) is a good place where to buy one. There you can find all Bioloid kits mentioned in this article as well as replacement parts, additional frames, sensors and boards.

Go back from “Bioloid” to “Build a robot”.

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