Easy robots

[xx544]

I am about to embark on a robot building project for my school.  My goal is to build robots who will then perform a PLAY.

I need help on finding easy robots to build that can move, and can be attached with arms and a speaker.  The arms don't need to be able to lift anything, I just want them to be expressive (how else will you know when the robot is sad?).

The biggest robots I have built are the Lego Mindstorms bots and a simple robotic arm (from a kit).  Any suggestions for starting points are welcome.

[Edit] I forgot to mention I am in North Carolina, USA. [/Edit]

[SixRingz]

You might want to start with a monologue... Don't know how much time you are to spend on this but to cast a whole play with robots sounds fairly complicated.  You might need to be a bit more specific also, like are the robots supposed to move on the stage or be static? In a static case I would go for RC servo controlled arms and a small speaker wich would allow for a simple cardboard box chassi.

[xx544]

I am not sure how long robots take to build, but I have over a year.  I hope that fits most time constraints.

I would like to have the robots move around, but if you don't think that is possible I can accept that.

[ALZ]

Do you have to build them? You can find many older robots on Ebay (don't go bidding too high) that may fit your needs. I know the "R.A.D." robot had  a speaker inside. 

[SixRingz]

Well, if you have a year you could probably do alot depending mostly on your motivation. Maybe you could go for a plan A and plan B, where the first involves moving robots. Worst case you end up with alot of experience but have to make them static in the end (Plan B) but best case you put some nice digital drama on video for the rest of us here to enjoy!! 
Very cool idea anyhow! Let us know the progress.

[xx544]

Ideally I would like the robots to perform the entire play without my input, so remote control robots like the RAD aren't exactly what I want.  On the other hand, if their is an easy way to modify them so I can pre-program commands, I would definitely try it!

If and when I get a performance going, I will try to remember to post a video here.

[ALZ]

A year may seem like a long time but it's not! If I was doing the project I would NOT pre-program each robot. It would be a nightmare trying to keep all the programs in all the robots in time. If you had to make one change in one robot then you would have to reprogram all the robot over again! I would feed the singal from the receiver on the RAD to a PIC which could decode a data stream so each robot would only move when it got the code that was meant for that RAD. Do a mod on the transmitter so that it could send out a data stream. Hook the transmitter to one cpu so that you only have to write one program. Now all the robots would be in syn.

Ideally I would like the robots to perform the entire play without my input, so remote control robots like the RAD aren't exactly what I want.  On the other hand, if their is an easy way to modify them so I can pre-program commands, I would definitely try it!

If and when I get a performance going, I will try to remember to post a video here.

[shlodo]

if u are a novice in robotics I would use your mindstorm kit as the brain.

You can easily program it then as that will be the hardest part. I think if you have one of the newer version mindstorm microcontrollers it comes with servos which are perfect for arms.

How long is the play? I think if the make the actions and movements quite simple then u wont have much trouble programming and getting in sync. U could even look at breaking up the program into sections that u could remotely initiate when u like, evectively keeping them in sync.

However mindstorms dont give out much power? How big and heavy do they have to be? You can modify and tinker with the output wires on Mindstorm to add a motor driver board or something for higher powered applications.

As for servos on a regular microcontroller, if u dont know much about electronics and programming this might be quite difficult.
I suggest a simple robot kit like the I.Box 3.0 with really simply programming.

[xx544]

RE ALZ:
I would definitely be interested in trying to rewire a controller if I knew how.  Is there any guide or starting point that I could look at?

RE shlodo:
My mindstorm is not sufficient for this.  It is one of the first kits, and it can't handle routines (just sensor/action feedback).  The latest mindstorms could do the trick, though.

One though I had for keeping them in sync (though it would still be difficult) was to make them wait for certain sensors to be tripped, so they could activate each other like a line of dominoes.  One robot kit I am about to try, as soon as it arrives, is the VEX system, at vexrobotics.com.  For the most part because it looks very customizable and has an easy computer connection.

I have a good deal of experience with computer languages like Java, Perl, PHP, etc...  But I have never tried to interface directly with machinery.  Any suggestions or guides on how that is done would also be appreciated.

Thank you all for the comments you have made so far, this is a very helpful site!

[ALZ]

Hi xx544:

You really need a scope if you want to play around with unknown ckts. My guess would be that it used a key system to transmit data. Meaning that it would turn the transmitter on and off to make high and low data bits.  You would have to move the sticks on the transmitter and see what comes out at the receiver on the RAD. If you don't have a scope, I would buy a PIC 2 programmer. They now have software that makes the programmer a logic probe. If you want to play around with a PIC you are going to need the programmer anyway.

By the way, unless you have the VEX programming kit, there is no computer connection.

"VEX system, at vexrobotics.com.  For the most part because it looks very customizable and has an easy computer connection."

How many robots do you need for this play?
 

[Rebelgium]

If I were you I'd make simple robots, with exactly the same electronics.
And have all of them have a WiFi or RF connection with ONE PC, then let this PC control all robots.
This way you can program the play in one piece of code on your PC...

[shlodo]

I bought the RoboBox 3.0 form inexglobal, it shows u how to hook everyhting out and it has better and easier programming than mindstorm

http://inexglobal.com/products.php?type=ROBOTKIT&cat=ROBOTKIT&model=robobox
dopwnload the manual in the downloads section and u can see exactly how it interfaces with mechanical actuators.

U will want to get high powered motor drivers tooo. and I dont think u can use servos on this kit, but done similar things by using dc motors with gearboxes so u can move arms slowly, integrate this with simple sensors and u will know what position they are at..

check it out

[Admin]

Hmmmm perhaps you should just buy a microcontroller, attach some servos and a battery, and call it a day.

Well, that, and program tons of robot acting . . .

It will probably cost you $150 for the whole project.