Advice starting my first robot

Projects General Guidance
1

I'd like to build a robot. Specifically, I'd like to build a semi-autonomous miniature look-a-like of Johnny 5 (from the Short Circuit movie). My background is in medicine (I'm a Radiologist) but I'm very competent at writing software and have some (limited) experience with AI / path-finding, etc (from writing games).

My issue is that I have very little experience on the hardware side of things. I currently own an Arduino UNO, a servo, some LEDs and basic components and have an ultrasonic range sensor on order. I have spent the last week or so getting a library up and running to control pins, etc on the Arduino from my Mac using my favourite programming environment (Real Studio) and that's coming along nicely.

Ultimately, I'd like the robot to be about 1-2 foot tall, have its motors/sensors/servos, etc controlled by Arduino and it's AI controlled by a custom programme written by my running on an inboard mini-PC (perhaps a pico-ITX board running Windows XP/7).

My question is a little vague but I really don't know where to start. I know I can't just go out and buy a prebuilt Johnny 5 kit for $1000 because my wife would definitely leave me! I need to start small and build up to my goal.

I thought about maybe prototyping a small version of the bot using Lego for the chassis/body?? Is that a stupid idea?

I have a couple of really basic questions, primarily related to the bewildering number of different components which mean nothing to somebody with limited electronics knowledge:

  1. The robot is going to need at least a couple of motors to drive the tracks (or wheels in the prototype). What would be suitable to use with my UNO? I assume the motors have a small axel protruding from them - what would be the best size to get, etc?

  2. I have a single servo on order (to tinker with to make sure my programming language can set specific degrees of rotation on it). Are there any good tutorials for beginners out there on how to physically connect servos to rods, levers etc so they can actually do something? It's all well and good being able to rotate a small plastic lever by 72 degrees but I don't even know where to begin when it comes to do something useful with them).

Apologies for sounding like a complete doofus but there seems to be soooo much basic ground to cover...

Thanks

2

hi

Any reason to use Real Studio over the standard Arduino IDE?

It is common for Universities to build robots out of technical lego.

  1. the size of motor depends on how big a load it needs to pull.

  2. Arduino motor/stepper/servo control - How to use (uses standard shield and library)

3

Go here and type the word "books" into the search bar. There is a book on robot drive trains.
http://www.robotshop.com/ca/home.html

I have been designing computer processors and autonomous systems all my life and been in this business over fourty years. I was thinking of being a Radiologist. Is there anything you think I could do for under $1000 to join your field? :roll_eyes:

I think you are doing fine. It takes a while to gain the knowledge. Surprisingly, your incredible knowledge of anatomy may become your greatest asset. How do I know what you know? Never mind...

One more point. a Mega2560 with Ethernet or Bluetooth for the Control link might be a far better choice because of the extra I/O and ADC pins. Just an opinion.

PS: By the time you are finished your wife may wish you just had an affair. It might be cheaper and less time consuming and more forgivable.

4

wilr-
hi. like you iam a noobie as well. unlike you, i am a millwright/machinist and have never done any programing-so i cant help you with the computer aspects as i'm just learning that. however, in regards to your motor concerns.yes, motors do have a shaft that sticks out of them.you can attatch "hubs" or wheels/gears directly to them. the size of your motor will depend on several things, like the wieght of your robot(chassis,battery wieght,motors,servos,sensor),how much power your gonna need and can supply,and whether you want a strong/slow,strong/fast,weak(for less power consumption)/fast or weak/slow motor to do those things directly or ifyou want a motor with a gearbox to do those things to make it easier on the motor. just shop around the net and do a little research on what different motors can/can't do. solarbotics.com is a great place for just about everything you will need for a robot and they have lots of info for they're products. sparkfun.com is a good place too.
as to your servo connection question. servos usually only turn left/right about180(maybe more)degrees or have continuous rotation. they almost always come with "horns"-they look like circles,x's or popsicle stick shaped. these horns are what you attach things to. if your wanting to use linkage to say,move a flap up and down, you'd mount the servo on something,connect the connector rod-maybe a coat hanger- from the end of the horn to an edge of the flap. unless your a math wiz,figuring out the exact length of rod,degree of rotation of the servo to movement of the flap is gonna be done by trial and error after a good starting guess. again, how big/powerful your servo needs to will depend on the speed you want the flap to move and the wieght of the rod and flap.
except for the electronics and programing, the best mechanical advice is to rough blueprint your robot-write out what you want your bot to do. this will ultimately determin what what you will need. draw out a large picture and then draw in all your motors,servos,sensors,etc..
also, your gonna need a motorshield.the UNO cant provide enough power to run two motors- the CMDR shield or Ardweeny multipack are excellent choices-available from solarbotics as well. either of these should provide enough ports to run all your servos,sensors PLUS two motors.
the awesome thing about arduino is this forum. there are so many outstanding members with TONS of experiance,knowledge and eagerness to share with noobies like us and help advanced individuals with they're projects.
linstructables.com and letsmakerobots.com are some superb inspirational websites for ideas and hacks if your stumped on how to engineer an aspect of your project.
best of luck, hoped i helped you out some.lemme know how things develope.
havefun.
-ed

5

darkcity:
Any reason to use Real Studio over the standard Arduino IDE?

Mainly because it's the language I'm most familiar with and the challenges involved in writing decent/interesting A.I. are big enough when you know the language - I'm not overly keen on learning a new one. Also, I plan on the robot being able to interface with services running on my local network, etc which would be a lot easier to achieve if its "brain" is just a regular PC running Windows/Linux (which Real Studio compiles apps to).

darkcity:
It is common for Universities to build robots out of technical lego

Cool - better dig some out from the loft :)[/quote]

darkcity:
Arduino motor/stepper/servo control - How to use (uses standard shield and library)

That looks like it might do the trick. It doesn't mention that it's compatible with the Uno on the site - anyone know if it is? When I put that shield on the Uno, will I have any other pins free for LEDs/sonar, etc or will I probably need a second Arduino board for the robot?

WillR:
Go here and type the word "books" into the search bar. There is a book on robot drive trains.
http://www.robotshop.com/ca/home.html

Bought. Looks interesting.

WillR:
I was thinking of being a Radiologist. Is there anything you think I could do for under $1000 to join your field?

You could probably buy a truckload of ultrasound jelly :slight_smile:

WillR:
PS: By the time you are finished your wife may wish you just had an affair. It might be cheaper and less time consuming and more forgivable.

She's pretty tolerant but point taken :slight_smile:

WillR:
One more point. a Mega2560 with Ethernet or Bluetooth for the Control link might be a far better choice because of the extra I/O and ADC pins. Just an opinion.

I think that's probably where I'll be heading. Either that or multiple boards connected via USB. One step at a time though...

@sigworth1103
Really helpful post, very clarifying - thanks a lot. Looks like I will be getting a motor shield.

This forum is great - so many helpful people. Too often on some forums, you get flamed for asking "newbie" questions but having crawled through this site for days this forum is very welcome.

Thanks.