Game playing robot arm

[Conscripted]

Hello all. I've finished $50 dollar robot. I posted some pictures in this thread. I'll add a sharp ir sensor to it in the next few days but I'm already thinking about my next project. I would like to build a robotic arm that can play Tic Tac Toe. I don't think a vision system is practical for me yet so I thought I might add a sensor for each possible move. It could be a micro switch or maybe a photo detector not real sure. I have three problems that i will need to overcome.

1. How would I monitor 9 sensors and be able to move three or four servos too?
2. I've never built a robotic arm
3. My programming skills are very weak.

Would it be possible to take a tic tac toe game written in C from the web and modify it? As I see it all the decision making would be programmed already. I would need to modify it code to move the arm to set positions instead of display the information on a screen. Would A program written in C for a PC port easily to AVR?

Thanks for any input provided.

Conscripted

[Ro-Bot-X]

I've seen Lego robots playing Tic-tac-toe. They were using the old RCX system, so the sensors were pretty limited. Most of them used a probe with 3 touch sensors attached to a resistive multiplexor, that would give out different voltage for each sensor combination. The probe would touch the game surface for each line, and the sensors would be actuated if a piece were to be found, the result being stored in an array. The robot would know which of the pieces were his and which were it's oponent's so after probing, a move would be calculated and a new piece added to the game.

To better understand the concept, please take a look at the best Lego Connect 4 robot:
http://www.teamhassenplug.org/robots/fullcontact/

And a description of an older Lego ATic-tac-toe robot with code:
http://www.marioferrari.org/ttt.html

And here is a vid of a Lego robot - oh, and I forgot to mention that the robots must clear up the table after the game!
[youtube]XhfGQGGFb68[/youtube]

[Admin]

1. How would I monitor 9 sensors and be able to move three or four servos too?

Well, its exactly like how the $50 Robot monitors 2 photoresistors. Just look at the code and expand it. The $50 Robot can only do 8 analog sensors. You'd need an Axon for more

2. I've never built a robotic arm

http://www.societyofrobots.com/robot_faq.shtml#robot_arm

3. My programming skills are very weak.

practice practice practice
(and take some classes and read some books)

[SmAsH]

1. How would I monitor 9 sensors and be able to move three or four servos too?

Well, its exactly like how the $50 Robot monitors 2 photoresistors. Just look at the code and expand it. The $50 Robot can only do 8 analog sensors. You'd need an Axon for more

how does it do that? i though it only had 6 analogue ports?

[Admin]

Oops sorry just 6 ADC. I was thinking of the SMD version of the ATmega8 (which has 8 ).


edit:

Code: [Select]

8) looks like to the forum . . .

[dellagd]

I'll put this in my list of projects-to-do

[Metal Slug 2]

I'll put this in my list of projects-to-do

Me 2  ...just one more of dozens I have planned for over the summer...

[Conscripted]

Well, its exactly like how the $50 Robot monitors 2 photoresistors. Just look at the code and expand it. The $50 Robot can only do 8 analog sensors. You'd need an Axon for more

For the sensors I only need to know if there is a piece present or not. Would it be possible to make a voltage divider or multiplex the sensors to indicate which positions are filled and which aren't?

Conscripted

[SmAsH]

you could use an ir emitter detector pair if its possible to have one on each side, or if not you could use a sharp ir...

[dellagd]

This makes you think.
Why don't more people use lego to build robot chassises?  I mean the guy in the vid made something like a gantry crane! I might try this...