Let's Make Robots!

Naughts and Crosses (Tic Tac Toe)

The Prizes

We had really great entries from all over the world with this competition. I didn't want anyone to go home empty handed so I have put together some runners up prizes and tweaked the main prizes.

I have added a 4 channel motor controller to 1st prize. This has the same footprint as the Spider controller and will stack neatly with the spacers supplied.

I've added a pack of 100 male to male and 40 female to female jumper wires to 2nd and 3rd prize to help them connect their controllers to their next project.

The runner up prizes are a wall chart with some information on basic robot electronics, a pack of jumper wires and a breadboard.


Most of the prizes got sent out today (Thursday, 28th) and the rest will get sent out tomorrow (Friday, 29th). Thanks to everyone that entered. It was really great to see robots from all over the world entering this competition!

The Tic Tac Toe challenge is over!

This challenge worked out better than expected with 8 entries completed and a 9th that was well on it's way but ran out of time. All the entries submitted are fantastic robots making this contest very hard to judge. Could all paticipants contact me through my contact form  and give me their postal address and a phone number. The phone number is required by the couriers in the event they cannot find your address or some other problem occurs.

The most important thing I was looking for was originality and creativity. I wanted to see robots that were not just obstacle avoidance, sumo or line followers. I intentionally kept the rules as loose as possible so that creativity would not be restricted. However I did tell Drewtoby that I would not consider a breadboard circuit with buttons and LEDs to be very original.

Unfortunately that is exactly what Theandroidman built. Admittedly Mark's entry was very impressive in that he built not one but two MCU's from discrete logic gates and counters complete with a homemade printer to print the game results. I think this project had more jumper wires than any other robot I've seen on this site.

It does not matter too much if the robot is unbeatable. The fact is the robot becomes boring to play against if it cannot be beaten. When I built my own robot I tried to include 4 levels of difficulty but none of them are unbeatable and I found the gameplay was more enjoyable as a result.

The Winners!

I've awarded first prize to DOC by Sebathorus. This is the only robot in the contest that had 2 arms, both arms moved and performed a function. This is the first robot I have seen using train track and it had a nice steampunkish look about it. I think a lot of work went into this robot.


2nd prize goes to Strike'm by Dipanjan. The robot could draw the playfield and could share a pen if required. It was surprizingly accurate and I think the way it reset the pen height was clever for it's simplicity. His use of pressure sensors made for a very good user interface with not buttons needing to be pressed.

Third prize goes to Skynet by Fifer253. This robot was original in that it pops ballons with a laser. I'm not sure if a computer controlled laser on a pan/tilt assembly counts as a robot or a weapons system but it is definitely different.


All the other entries had a lot of time and effort put into them and I think we all appreciated seeing them in action. I will try to send something to everyone who participated by the end of the week.

Reasons why some entries did not win:
There is always some controversy, especially when the definition of a robot comes into play but for this competition I did not feel that the entries by Theandroidman and Drewtoby really fitted the definition as well as the other entries.

The robots enter by Rick100 and Screwdriver were both nice robots but their gameplay logic came from an old magazine article. I also prefer robots that can play regardless of who starts first and can play starting from any position even if they are not unbeatable.

SkeptiKal's entry could have been a winner but it obviously needed more work to improve it's precision and it occasionally dropped pieces. It was the only delta robot and I hope he will refine the design.







I have posted my own Tic Tac Toe robot here: http://letsmakerobots.com/node/35933.

This robot is not part of the competition but perhaps it can inspire a few last minute entries plus it ensures I comply with the rule "You cannot post a challenge that you cannot solve yourself".

This challenge is simple. Build a robot that can play naughts and crosses (Tic Tac Toe) against a person. It does not matter how. points are awarded for originality with bonus points if it can win or be drawn every time.

You can use any processor from a picaxe 08M to an IBM BlueGene/Q super computer. You must post video of the robot playing again a human for 3 games in a row.

The due date is now 25th of February, 2013 because I am not sure exactly when DAGU will have holidays for Chinese new year and some members have asked for more time.

There will be 3 prizes:

  1. DAGU Spider cotroller with HD servo shield
  2. DAGU Micro Magician V2
  3. DAGU Mini Driver

I will judge the contest. Originality is important!

Maybe you will make a super tiny robot arm with toothpick and hotglue.
Maybe you will use magnetic pieces on a glass top with a 2-axis system underneath to slide the pieces into position.
Maybe the pices will be paper and your robot will use a static charge to pick up the pieces.
Maybe each piece will be a robot controlled using a mobile phone and bluetooth.

Note: Your robot can draw Naughts and Crosses or it can move pieces. As long as the pieces can be easily distinquished in the video they can be different shapes or different colours. If your robot is drawing then it can draw any shape as long as the human draws a different shape or uses a different colour.


Spider Controller:
This is a great controller for animatronics as it can drive up to 48 servos using the Arduino servo library. Even if you don't want to drive a lot of servos, the extra memory, PWM, analog and digital pins allow you to create far more advanced projects than is possible with a standard Arduino.

The 3A switchmode power supply allows the controller to work with input voltages from 7V to 30V with enough current to drive a number of servos directly from the controller. All 70 I/O pins are terminated with a 3 pin male servo header (includes +5V and ground) plus a female header for jumper wires. The heavy duty servo shield allows the controller to drive heavy duty servos directly from the battery or a separate power supply with a common ground.

Recently the prices of ATmega2560 MCU's has dropped. The Spider controllers are now compatible with the Arduino 2560 and come with the 2560 bootloader installed.

The heavy duty servo sheild is small than the controller so it does not block any pins or the reset button. This allows high powered servos to run directly from the battery while miniature and standard servos are powered from the controllers 5V supply. A screw terminal on the sheild breaks out the 5V rail for powering other devices while a small prototype area in the center allows custom circuitry to be added.


  • ATmega2560 @ 16MHz with 256K FLASH, 8K SRAM and 4K EEPROM memory.
  • 70 I/O pins terminated with 3 pin male header and 1 pin female header.
  • 16 Analog inputs
  • 14 PWM outputs
  • 4x serial ports
  • 1x I2C
  • 1x SPI
  • 5V @ 3A switchmode power supply with input voltage from 7V - 30V (no 3.3V).


Micro Magician V2:
This is a small controller but has a lot of features built in so that you can build a working robot without a lot of shields or external components. This controller is 3.3V allowing you to make robots that run from a single Li-Ion or Li-Po cell. Despite it's small size this controller can drive up to 8x miniature servos directly from the PCB making it ideal for small QuadBots.


  • Small size: 30mm x 60mm.
  • Input voltage 3.6V to 9V with reverse polarity protection.
  • Built in 5V @ 1A and 3.3V @ 500mA LDO regulators.
  • ATmega328P @ 8MHz (3.3V) with 32K FLASH, 2K SRAM and 1K EEPROM memory.
  • Dual FET "H" bridges with electronic brakes, current limiting and stall detection flags.
  • 3-axis accelerometer with ±1.5G or ±6G range and 0G (free fall) detection.
  • IR receiver provides up to 128 virtual buttons using Sony IR Code (SIRC).
  • 8x Servo headers with selectable power directly from the battery (reverse polarity protected).
  • Built in USB interface (no FTDI interface needed).
  • Comms socket for bluetooth or Xbee transceiver.
  • ISP socket.
  • I2C interface.
  • Indication LEDs for Power, D13, RX, TX, and IR.
  • Custom Arduino library for simplified use.


Mini Driver:
The Mini Driver is a basic controller, ideal for small robots. It is a 5V controller with built in USB interface and motor drivers rated at 2.5A each. Despite it's small size this controller is capable of driving 8x miniature servos directly from the PCB making it ideal for QuadBots. Although the recommended minimum voltage is 5.5V, 4.8V NiMh or NiCd batteries can be used.



  • Small size: 30mm x 60mm.
  • Input voltage: 5.5V - 9V with reverse polarity protection.
  • Built in 5V @ 1A LDO regulator.
  • ATmega8A @ 16MHz with 8K FLASH, 1K SRAM and 512 Bytes of EEPROM memory.
  • Dual FET "H" bridges rated for 2.5A each.
  • 8x servo headers with selectable voltage (5V or +Battery).
  • Built in battery voltage monitor on A7.
  • Comms socket for bluetooth transceiver.
  • I2C interface.
  • ISP socket.
  • D13 and power LEDs.



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I have received the prize(.Sorry for the delay,was out of station). THANKS THANKS THANKS !!!

The poster will be put to good use!

Great to hear. I think all of the prizes should have arrived by now so I am looking forward to seeing some new cool robots on the front page :D

But I never make the front page anymore. I am more of blog and go type.


Thank you for the awesome loot!

Thanks Oddbot for putting on the challenge and for the prizes . I enjoyed seeing all the entries .

Thanks a lot Oddbot. Thanks again for those jumper wires, this challenge meant a lot to me..... This was a really COOL challenge...Can't wait to get the gifts you are sending. Thanks a lot.

I agree: thanks!

My hearty thanks to DAGU too....


Work got and my overly ambitious design got in the way of finishing mine, but it got me thinking and motivated.  I hope to have it complete over the next few months and will post it then.



I'm glad to hear it got you thinking. I think that is the true purpose of LMR.