Shop OBEX P1 Docs P2 Docs Learn Events
Random walk duration seeking inspiration. — Parallax Forums

Random walk duration seeking inspiration.

BritannicusBritannicus Posts: 98
edited 2011-07-02 12:38 in Robotics
've been asked to do a small piece as a fund raiser for my Son's School - the idea is to make some small 'bots which will run around a course, either randomly then stop or round a fixed course for a random period of time (say 30 secs to 1 minute). I'd originally thought of bristle bots they're fun , quick to make and cheap - maybe 2 side by side linked "catamaran style". Ideally I'd work with the 10 year olds to make them.

Alternatively some sort of line follower that runs for a random period round a divided track. but in any case small and cheap to produce, say five. Sadly for cost reasons this is probably going to be BEAM rather than Microprocessor based.

The idea is that they'll be used to select winners for a prize - pay fifty pence, if your bot stops on a prize winning square you get a prize!

Now's the question I'd throw out to all the electrical genii out there (and I know you are !) - what's the best way to set up either a random walk for a fixed period - or a walk for a random period (or both!).

If I go with a bristle bot it's got to be tiny and cheap - I'd wondered about replacing the battery with a capacitor, I could charge from a battery and it'd run till it ran out of Gas - would this work ? what size cap would give me 1.5 V for say 30 seconds ?? what are the rules for length of charging - I know nothing about caps. Anyone got any brilliant ideas for a compact under 10 gramme solution ?

Comments

  • kwinnkwinn Posts: 8,697
    edited 2011-07-01 17:17
    Not really sure how long a supercap would run, but they are not cheap (~$4.00 - $5.00 CDN ). Perhaps a CR2032 battery and a 555 timer chip would be better. The batteries are about $25.00 per 100, and the 555 is about the same price. With the required capacitor and resistors total cost should be under $2.00 per bristle bot.
  • ercoerco Posts: 20,256
    edited 2011-07-02 12:29
    Caps just slow down until they stop. Not real fun, like watching something die. Alternatively, keep the batteries in and run it like a cockroach race. Dump all the bristlebots in a center bulls-eye target and see who makes it into the outer circle first. They turn and go in random directions, which adds to the fun.

    Regarding randomness: as we say in the toy biz, if you can't fix it, FEATURE it!
  • graffixgraffix Posts: 389
    edited 2011-07-02 12:38
    erco wrote: »
    Regarding randomness: as we say in the toy biz, if you can't fix it, FEATURE it!
    thats a good one
Sign In or Register to comment.