Let's Make Robots!

Doodle Bot

Draws nonsensical pictures
Doodle_Bot.zip959 bytes
microM_V1.3.zip8.17 KB

Having one of those days where your too lazy to do anything? Have a robot doodle for you while you sit back in your favorite chair. This is a very simple drawing robot that was actually started by one of our student engineers. I just made the base plate bigger so I could add a third servo to raise and lower the pen.

My base plate is laser cut acrylic but it could easily have been a small food container, CD or a piece of wood. Just use some double sided tape or hotglue to hold it all together.

Because the Micro Magician has the dual "H" bridge, IR receiver and servo outputs already built in this is a very simple robot to build. Just plug in the batteries, geared motors and servo.

I set the servo voltage selection jumper to 3.3V. Some servos will not operate at 3.3V but the little black duck servos seem to work fine, just a little underpowered. I could run the servo directly from the battery but it is 8.4V when fully charged which is dangerously high for a 6V servo.

Programming was easy as well. The Micro Magician library has drivers for the H bridge as well as the IR receiver. I have attached the code and latest version of the Micro Magician library which can also be downloaded from my product support site: https://sites.google.com/site/daguproducts/

This robot is a great way to entertain the kids on a rainy day. Simple to build and easy to use.


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The board can operate from 9V but a 9V battery cannot deliver a lot of current and would die very quickly. I would suggest a 2S LiPo (8.4V at peak charge) and to replace the Vbat jumper with a couple of 3A diodes such as the 1N5400. Each diode will drop the voltage by about 0.7V and ensure the motors are not overly stressed.


I would like some clarification on the maximum operating voltage of this kit. Would the motors be damaged if the kit was operated from a 9V power source?


A bit more background into what I would like to do.

I recently bought this kit and so far it looks to be fantastic value. I am planing to make it internet controlled via an Intel Edison module. My issue is that the Edison requires either a 3.7V (single LiPo cell) or 7-15V power source.

I noticed in the kit description that the board can safely handle up to 9V, so my immediate thought was to power the whole system from a 9V equivalent battery. However I noticed that the H-Bridge driver appears to directly transfer Vbat to the motors, and from the instruction book, I noticed that the operating voltage of the motors is 6V. So I am worried that though the board appears to be able to operate on 9V, the motors may be damaged.

Thank you


I was very exited to build this robot, so once I recieved the kit I build it right away.

Strangly the motors for the wheels did not spin. The documentation supplied mentions that the motors can be a bit stuck and after some use they will loosen up. So it tried and tried and was able to get one to work. The other no luck. It can hear it work but the wheel is not spinning.

So I emailed Claudia (contact person to order the kit from) but have not received a reply.... Can anyone tell me what motors the kit have so I can try to find them somewhere else to buy. I dont want to trash the kit just because of this.

Any help (hopefully from Cluadia) is apreciated.


Claudia said she did reply but now she is training a replacement so you might get an email from Pome instead. She says the motors are being posted today.

Thank OddBot. I recieved her email this morning. She is sending me a replacement motor. That is great customer service.

Again thanks.


Congratulations, this is really a great project! Small and very precise moves.

Damn, double posted again :(

We talked to the servo factory that makes the black duck servos.

In the future (about 4 weeks from this post) we will have them available as a simple geared motor as I used in DoodleBot. They are a nice combination of small size, good torque and low cost. The standard servo housing makes them easy to mount and they can be run from any controller with a dual "H" bridge such as an L293D.

But is this robot having any sensor .

The only sensor being used is the IR receiver.