Picture of Control an OWI Robotic Arm with Arduino
The OWI Robotic Edge Arm is a cheap and terrific 5-degree-of-freedom robotic arm that just costs $37. It's a great kit to build with a kid and won't take more than a couple hours to finish. Out of the box, it can only be controlled manually with a remote control. You can buy a USB control interface for it, but it's a waste of $27. It just lets you add a series of timed moves, but it's not really scriptable, you can't have it loop and because it just uses timing, there's no reliable repeatability.

What you want is real computer control, with closed-loop feedback for precision. Good news: it's super easy to connect an Arduino board to the OWI arm and let it do all the work! You won't even have to take the OWI arm apart or damage it.

Here's a video showing it in action, under fully autonomous Arduino control:

Here's what you'll need.

1) OWI Robot Edge Arm ($37)
2) An Arduino Uno board ($30)
3) An Adafruit Motor Shield ($19.50)
4) One potentiometer and at least three little trimpots ($5)
5) Some perfboard to mount the pots ($5)
6) Some jumper wires ($6) and pin headers ($7.50)

The total should be around $100. But you may have some of this already, and if not, you'll be able to reuse these boards and other parts for countless other projects.
photoace121 year ago

hello, i was wondering how i could do this without paying for all the shields, all i have is an Arduino UNO, a breadboard, wires and the robot arm, is there any idea as to how i can make it work with those components

nope you need a motor shield

The simplest is still to use an Arduino Mini/Nano clone (with USB included) that sell for about $2 (shipping included), and plug it into your homemade motor driver (basically, relays activated by transistors), and you're free to design your motor drivers the way you want. That's the base design I use for servos and step motors.

AbhishekK132 months ago
AbhishekK132 months ago

I bought OWI kit from amazon. It seems the speed of the motors is a bit slow.
Are there any methods to increase the speed of the motors?
Something like passing more current. But i doubt more current may burn the motors.

Moon747 months ago

Hello zlite,

Great project and idea!

What is the name of the software you are using on the youtube video "simple base movement in action"? I will add the pots and I would like to control it from my PC like you are doing on your video.

Thanks in advance!

zlite (author)  Moon742 months ago

That's just Arduino

joesinstructables made it!1 year ago

Clever idea. Thanks for sharing it.


Hello! Great that you made it!

Are you using the "Serial Monitor" to control the base with the keyboard? How can I assign the keys?


Moon747 months ago

Hello! Are you using the "Serial Monitor" to control the base with the keyboard? How can I assign the keys?


Datawolf3 years ago
Does a shield exist that would enable the control of the 5 motors ?
I would love to program an arduino for the arm to pick up a light, or something like that.
@Datawolf could u program an arduino for my robotic arm to pick up objects with a gripper.?? plz rply soon
Datawolf dhoni119 months ago
Gasp. I wish I had enough time for my own projects !
Good luck
Unfortunately I didn't found a shield to drive 5 motors.
And even that, I don't have time enough for my own arduino, which is gathering dust in its drawer...

The AVR328P has 6 PWM outputs and 6 Analog inputs (if you don't use the I2C bus), you possibly just want to wire your motor driver yourself instead of using shields.

zlite (author)  Datawolf3 years ago
Datawolf: I don't know of a 5-motor shield, but you can add a single motor shield (stacked) to the Adafruit one to get five total.

Here's one:
froibo zlite3 years ago
Just to clarify, by fingers you are referring to the vise, correct? I have yet to get my arm yet, but I would think it would be disappointing if it was not able to grab anything.
Is the link for "potentiometer" is good?? I think it's a trimpots and doesn't match to the potientiometer that you use on photographies. Is the good link is that: http://www.adafruit.com/products/562 ???
very good tutorial for OWI Robotic Arm. I'm looking forward to find tutorials for other robotic arm kits 
WVvan2 years ago
A big THANK YOU for the idea about how to mount the pot to sense position. I've been beating my head for the last couple days trying to figure out a similar problem. I'll be using your design. Much better than what I had in mind. Kudos!
Is it possible to use External DC Power 6v ?
i tried to do it but it going one side only ,
i connected the possiteve signal to the + and the possiteve to GND and -
but it not working .
can help please ????
Hi there, i am just wondering if it would be possible to control the arm without the potentiometer and trim pots? I have got the Arm going with a basic loop BACKWARD, FORWARD , and only one motor at a time (using adafruit DC test) i was hoping to be able to use the serial monitor like you have done as well, is this possible without modification to the arm?
nmered3 years ago
Great instructions! I got a sensor-less version of this set-up running. Now I'm looking to control the fingers. You mentioned adding relays and microswitches to the digital outputs. Do you have any hardware specs on these parts? I'm new to electronics in general and am using this project to get in to the basics.
Check this one out on youtube. The dude attached a freakin' cam.

What voltage do you supply to the motors using this shield? I thought they run on ~3V but the h-bridge you're using seems to have a min of 4.5V. Do the motors seem to cope ok with this?
zlite (author)  Dainbramaged3 years ago
Yes, they're fine with that voltage. The stock OWI kit uses four 1.5v batteries in series, so that's 6v. We're running them at somewhat lower voltage (4.5-5v) out of the shield, but there's no noticeable performance difference.
nhecht zlite3 years ago
Actually, the circuit is set up so that only two of the batteries supply power to a motor at the same time, so the motor only sees 3 V. The circuit's "ground" is the middle of the battery string, which is connected to one side of each motor. The hand controller will connect the other motor pin to the pair above the ground for forward motion, and the other pair for backward motion.

I'm running my own Arduino-controlled OWI arm using a 5V supply for the motors, and it seems to be working fine, for now. We'll see how the motors hold up as time goes on.
What kind of motors are in the arm as-shipped? If they're servos, as I assume, they already have pots in them. I wonder if it's possible to use the existing pots (if they do actually exist) and something like the OpenServo board from Sparkfun (http://www.sparkfun.com/products/9014) with the Arduino for control, and avoid the additional wiring. Thoughts?
zlite (author)  dustynrobots3 years ago
Dusty: They're not servos. Just standard toy brushed motors with gears. No pots or any other feedback.
oh okay got it - thanks for clarifying!
I have one but...the motors are two slow.
mrrepel3 years ago
Looks nice ! Still waiting for my robot arm to arrive. Nice coding,i want to use an old PS2 mouse with rotary encoders. I'll use some of your code :)