Let's Make Robots!

Nano Sumo (Electronics)


I give you the Nano Sumo bot, a collaborative project between myself and Gary. View Gary's post on Mechanics here

I think this bot "is" many things. Smallest robot using the Arduino bootloader ? Smallest robot with a microcontroller on LMR? Best use of Solarbotics Planetary Gear Boxes? 

At the heart of the Nano Sumo is my custom designed micro-controller. It uses a Atmega-328 with a Arduino bootloader programmed into it via the on board ICSP socket. It also has a FTDI programming port for programming it with the Arduino IDE. It measures 21mm x 23mm and has 3 analog inputs, 2 PWM outputs, and 4 I/Os. The PCBs were made by Seedstudio. The Eagle files are available for download here.




The pin layout is designed to mate perfectly with the Sparkfun 1A Dual Motor Driver. The outputs of the Nano’s micro-controller board plug directly into the inputs of the motor controller. This allows for the control of 2 motors with PWM for speed control and breaking. The only other needed connection is a wire providing power to the motor controller.


The power source is provided by a single 50mAh 20C li-poly battery. this provides the system with 4.2v when fully charged and can supply up to 1A. A female connector was added on the end to mate with a male connector on the bottom of the micro-controller and on the charger.



A charger had to be built for this battery. The charger i built uses a Maxim 1555 Li-poly charger IC. It has a LED status light to show that the battery is charging. The charging is powered by a 4 AA battery pack so there is no need to be near a wall outlet to charge. The circuit was completely built on a Sparkfun breakout board (seen as the red PCB in the picture)



There are 2 sensors on the Nano sumo robot. One is an analog reflectance sensor and the other is a digital obstacle detector. The analog sensor is your common line sensor that can sense black and white. This sensor is used to stay in the sumo ring, because if you leave the ring, you lose. The obstacle detector is a very tiny digital sensor that gives either a 1 (no obstacle detected) or 0 (obstacle detected) reading. This is a surface mount sensor that does not come assembled. I soldered it together with no problems, but it was not easy. The sensor has a range of 6 inches, which is just about right for this class of sumo. 


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I have no hot air rework station, i might have to look up how to do it with out one.

It wasn't done with a hot air rework station...  :) just a good ole soldering iron.


Looking further, I thnk this is the stuff the guy used...



and what makes it nice is you know you can get it for cheap.....


Brill Team work there lads :-

These should go into mass production.............. guys..........really guys.

Amazing nano size and compact construction - speed and agility......... it has it all.

I agree that this is a marketable. Most people won't want to do the assemply and solder reflow stuff. If a manufacturer could be contracted to produce them, I think the cost for quantities could be acceptable. It is especially beneficial that it interfaces directly with a popular motor driver board.

This tiny robot is awesome and if its not possible to sell it please, please make  a how to tutorial on how to make the mechanics

and the electronics so others can make it too.

Great Work.

These are very cool!


U used the the same motor driver as my robot. TB6612FNG breakout right? if so how would You rate it?

It was perfect for this application because it was so small and had a good pin lay out that i could design the board around. PWM pin is great too. I would consider using it on some future small robots.

I used it because it fit the bill & it does the job well

As soon as I saw this I thought it would be pretty sweet to see this kit in a shop, it sound simple enough for beginners if all the SMD bits are already soldered.


Great job :)