| | | | | Hi all,
I am trying to get some middle school kids playing a bit with the robosoccer
idea. I don't want to frustrate them with the fluctuating IR ball. So, I am
planning to find a constant "lighted" ball for them instead, but no luck.
Wonder if anyone may have a suggestion.
By the way, the official IR soccer ball has a very unreliable IR emission.
there are times my IR sensor just simply did not get any feedback even when
it is right next to it. For my high school kids, I had them to implement
some kind of either probability, or just simply skip the reading if there
are spikes of drop. Therefore, for the younger ones, I'd like to find a
lighted ball. any suggestion is appreciated.
--Elizabeth
--
MIME ATTACHMENTS DISCARDED:
1. Content-Type: text/html;
charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
Content-Length: 2962
| | | | | | | | | | | | |
| |
| In lugnet.robotics.edu, Elizabeth Mabrey wrote:
> I don't want to frustrate them with the
> fluctuating IR ball.
It's not ideal for stock LEGO sensors I think, but it might be good to point out
to them that the reason it blinks is to make things *easier*. With a source
pulsing near a known frequency, ambient conditions are much easier to cancel
out.
> I am planning to find a constant "lighted"
> ball for them instead, but no luck.
I've not seen them either. But I would think this is something a friend could
make with a battery pack and a bunch of near-IR LEDs. Perhaps a first step (for
them to practice on) can be a "target RCX" driving 3 light sensors (or an NXT
driving 4). You might even be able to stack two RCX light sensor on each RCX
port, to get 6 near-IR (although dimmer) light sources, and arrange them in a
circle facing out.
> the official IR soccer ball has a very unreliable
> IR emission. There are times my IR sensor just
> simply did not get any feedback even when it is
> right next to it.
It might be that the pulses of the IR ball were out-of-sync with the reads of
the light sensors. Have you tried looking at the IR ball through a stock video
camera? These usually have very good IR sensitivity, so you can "see" the IR in
the playback. Spybots are rather impressively flashy on video.
--
Brian Davis
| | | | | | |