In my university we need to buy arduino boards and kits to build a moving robotic arm, that moves up and down and clockwise in a specific degree (almost like humans's).

So, what's the most suitable arduino board to build this arm? I suggested to use the basic UNO board, but we may need to use relays (for example) if the power source is 12volts. So there is should be a better one.

My regards.

  • There is no Arduino that runs on 12v. To power higher voltage motors you'll have to learn about transistors. The question of which Arduino to use depends on how many input/output pins you need and the form factor. If you need lots of pins then go with the Mega or Due. If you don't need a lot of pins and size doesn't matter then go with the Uno. If you want a small size go with the Nano or Mini (these are harder to prototype with).
    – Jerry
    Oct 31, 2015 at 10:15
  • Thank you. I thought that mega can run on 12V. It's their (the university staff) to make or find the transistors. We will see if UNO is suitable. Thanks again. Oct 31, 2015 at 10:22
  • @Jerry The UNO does run on 12V. It dissipates lots of power but it does run on 12V. Oct 31, 2015 at 10:22
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    This attitude that part of the problem is the staff's job, and that you will somehow select the controller in intentional ignorance of that, is going to cause untold headaches, delay, and team conflict in your project - if it doesn't ultimately cause you to abandon the effort unfinished. You all need to sit down together, define the problem, and figure out the constrains which that imposes on each system, and the inter-relation between the decisions made for each component. Oct 31, 2015 at 16:38
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    If you buy something like an Uno or a toy robot arm now, accept that you are doing it to learn about the issues (which can indeed be a good idea when you have no perspective) but be realistic that it is not necessarily going to be part of the final implementation, and be prepared to change based on what you learn. Oct 31, 2015 at 16:40

2 Answers 2


If you are hoping to drive the arm straight from the Arduino, that's not going to work.

What you should do is:

  • Define the maximum weight and size of the load your arm will carry.
  • Define expected precision and speed of the movements.
  • Count the Degrees of Freedom (DoF) your arm will need (1 DoF = 1 simple joint)
  • Figure out size and materials of each part of the arm
  • Calculate the torque required at each joint (yes, you need some basic physics calculation)
  • Identify the motors you want to drive (DC are inexpensive but not very well suited for this, without lots of additional control logic & HW - stepper motors are better, but they still do require some additional effort - servos are the easier way but they are a bit more expensive)
  • Define the requirements for both the micro controller and the power supply, based on the previous choice.

If you can refine your question, based on the few points I sketched, you will get ahead much faster and with less risk later on to have to backtrack and re-design something.

You might have already answered some of those steps, then I suggest you list here your choices.

Similarly, if you are referring to some link you found (instructables, etc.) please post it.

As reference, hobbyking has an extensive catalog of motors and power supplies. You can find the same items also on ebay, but hobbyking can be used at least as reference for various specs (power, torque, weight, etc.).

  • Thank you for the answer. Can we use something like 'arduino motor shield'? these physics calculations is the staff job, they asked me the board and kits that can do this work. They want something like this Robotic arm on amazon I did not find any instructions that suitable for this project. Oct 31, 2015 at 10:49
  • @HorizonDragon If the "staff" haven't specified the kind of information Igor has mentioned then you cannot do the job properly. Go back to them and ask them for more detail so you can know what kind of power is being expected.
    – Majenko
    Oct 31, 2015 at 10:59
  • @HorizonDragon that link you posted would be even scarier for me :-) because it relies on levers to perform combined movements, instead of having a motor at each joint. It's an approach pulled out by kits that want to stay on the cheap side and has the advantage of being lightweight. The drawback is that even if you have apparently several dofs, in practice they have mechanical constraints on which movements they can perform and are not so easy to control. Oct 31, 2015 at 11:13
  • @HorizonDragon something like this [1] might be easier to deal with, albeit more expensive. [1] ebay.com/itm/… Oct 31, 2015 at 11:15

Best answer is Arduino Uno because it is enough for your application.

But all Arduino are works on 5 volt or 3.3 volt.

For operating 12 volt devices use transistors or MOSFETs.

  • If you're going to use transistors/mosfet I would say arduino Nano plugged into a breadboard is easier to use. Or use an Arduino Uno with a motor driver board. (But I think it's better not to since they are limited in the amount of motors they can drive, and you'll be very likely driving servo's, not DC/Steppers).
    – aaa
    Nov 3, 2015 at 7:39

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