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reflex tester game?

C

clicker

Jan 1, 1970
0
I've been wanting to build a fun reflex tester for my kids. I've got
the basic idea of using a decade counter to light a series of leds. The
lights would start the countdown and when it got to the last one it
would signal the kids to see who could hit a button the quickest. I was
thinking of something that would have 4 or so buttons so they could
play as a group.

There would have to be some way to make sure anybody who jumped the gun
didn't win the game and also some way to make sure somebody can't just
hold the button down continuously from the start and fool the game that
way.

Any ideas?

Pete
 
N

Noway2

Jan 1, 1970
0
You could use a signal that indicates that you are counting down, then
if a button is pressed while this signal is active you can generate an
error condition that would indicate who the guilty party was. Without
thinking through the details, it seems to me that you will need similar
control signals to latch the first button press and lock the others
out, so you may already have something that will work.

How were you planning on implementing this circuit? I might suggest
that you consider a microchip PIC, but it can be done other ways too.
 
C

clicker

Jan 1, 1970
0
I'm not up to speed with PICs yet but am comfortable with the more
traditional 555's and such. I think it could be done this way but I'm
no expert here.

Pete
 
N

Noway2

Jan 1, 1970
0
Yes, your circuit should be simple enough to implement with timers,
discrete logic, and some small IC counters and flip flops. If you are
fairly neat in your workmanship you can probably even get away with
building the circuit on a breadboard and then fabricate a simple
circuit board. To me this sounds like a good fun project that would be
challenging but do-able.

How familiar are you with truth tables and minimization through
Karnaugh maps? What about state machine diagrams? If you aren't very
familiar with this, I would recommend that you get a book on digital
logic and switching. Probably about the time you get half way through
the book you will have everything you need to do this project. A book
on digital electronics geared towards hobby work would likely even have
projects to build a bread board system. I have a book on my shelf
"Digital Electronics Guidebook", by Mike Predko, which I believe I
ordered through Amazon. This type of book may be a good choice for
you. It covers the digital and analog electronics including
transistors, counters, flip flops, 555s and up to simple processor
based stuff.

With the bread board approach, you can then build up a small section,
such as one of the truth tables or state machines, counters, etc and
experiment with each one seperately and then start putting them
together. If you don't have one, you can probably get a bread board at
radio shack or an online company. I had one floating around but I
can't find it to tell you where I got it, but I think it was something
along the lines of "circuit specialists".

The way I would recommend starting is to think about the inputs you
need / have and the outputs you want. Then either draw a set of truth
tables and or state transition diagrams. This will give you the basic
logic equations, which you can the minimize to reduce the number of
gates, wiring., and cost.

If you are ambitious enough, this would be a good PIC project. I have
seen books on PICs even in places like Barnes and Nobles and Borders.
I say that this would be a good PIC project because a lot of the
functionality you are after would be pretty easy to implement with
simple software. You could then use the IO pins of the chip to drive
the LEDs or drive some decoders, etc.
 
J

Jasen Betts

Jan 1, 1970
0
I've been wanting to build a fun reflex tester for my kids. I've got
the basic idea of using a decade counter to light a series of leds. The
lights would start the countdown and when it got to the last one it
would signal the kids to see who could hit a button the quickest. I was
thinking of something that would have 4 or so buttons so they could
play as a group.

There would have to be some way to make sure anybody who jumped the gun
didn't win the game and also some way to make sure somebody can't just
hold the button down continuously from the start and fool the game that
way.

Any ideas?

hmm you need to disqualify anyone who presses early

so there's 3 states for each input

unpressed, pressed early, and pressed on time
to store 3 states takes 2 flip-flops

make 4 of these... "input units"

(reset)___________________
| ___
+-|R Q|--- cheat
(early)------------|~~\ | | _|
| & )--|-|S Q|O-----|~~\ out
__ +--|__/ | ~~~ | & )---
(press)--| \ | | +---|__/
| & )--+ | ___ |
(enable)-|__/ | +-|R Q|--+
+--|~~\ | |
_____ | & )----|S Q|
(early)------------|__/ ~~~


now, how to hook the 4 input units together.

_____
the (early) , (early) (reset) and (enable) inputs are common
among all the input units, (press) is wired to go high when
the button is pressed.

reset goes high momentarily to clear the output and start a new game
(attach it to the decade counter output 0 pin) ...
_____
(early) is inverted (early) or vice-versa (attach (early) to out 9 (or
whechever out on the decade counter means _____
press now) and use an inverter (or out 8) to get (early)

wire the 4 outs to a 4 input nor gate (or equivalent) and the output of
that to enable.


how it works,

after reset (early), and (enable) are both high and so any signal on
(press) will set the upper flip-flop.
_____
once it's time to press early goes low (and (early) goes high) now any
high signal on (press) will pass through the lower and gate and set
the lower flip-flop

if the lower flip flop is set and the upper is not set that's two high
outputs to the last and gate which makes out go high,

that makes a high input to the 4 input NOR gate (discussed above) which
makes enable go low blocking all the buttons from effecting any further
flip-flops until the game is reset.

the winner is the one with a high "out"
(attach the indicator this output)

Any cheats will have a high "cheat" output.

if you want the game to restart autommatically after a winner has been
found attach reset further down the decade counter and use a 4
input and gate to detect the case when all four players cheat.


the "christmas tree" traffic lights used for starting drag races have a
random delay between the yellow and the green light you may want to
consider implementing this feature in your game so that players must
react to the "go" light instead of just judging when it will light,


Bye.
Jasen
 
R

Rich Grise

Jan 1, 1970
0
I've been wanting to build a fun reflex tester for my kids. I've got
the basic idea of using a decade counter to light a series of leds. The
lights would start the countdown and when it got to the last one it
would signal the kids to see who could hit a button the quickest. I was
thinking of something that would have 4 or so buttons so they could
play as a group.

There would have to be some way to make sure anybody who jumped the gun
didn't win the game and also some way to make sure somebody can't just
hold the button down continuously from the start and fool the game that
way.

Yeah - people have been building these things for decades:

http://www.google.com/search?q=jeopardy+button+circuit

Cheers!
Rich
 
B

Bob Monsen

Jan 1, 1970
0
I've been wanting to build a fun reflex tester for my kids. I've got
the basic idea of using a decade counter to light a series of leds. The
lights would start the countdown and when it got to the last one it
would signal the kids to see who could hit a button the quickest. I was
thinking of something that would have 4 or so buttons so they could
play as a group.

There would have to be some way to make sure anybody who jumped the gun
didn't win the game and also some way to make sure somebody can't just
hold the button down continuously from the start and fool the game that
way.

How about a random timeout that drops a ruler? The victim puts their
fingers near the 12" mark, and a solenoid is used to release the thing.
The score is where they grab it, in inches...

You can get solenoids here:

http://tinyurl.com/bfscc

This one is a 12V DC relay, which means you'll need some kind of voltage
source. This one might work (from the same guys:)

http://tinyurl.com/bvqvb

(check the current rating of the solenoid)

You can either just have a little normally open button to work it, or a
timer of some kind.

Here are some buttons:

http://tinyurl.com/aa3z5

If you think you want a random timer circuit, I can design one that will
work for you, but the button is probably the easiest, and if you put it at
the end of two wires, you won't have a problem hiding the activation.

You'll have to build the stand, get the ruler, and figure out how to
reset it...
 
J

Jasen Betts

Jan 1, 1970
0
I'm not up to speed with PICs yet but am comfortable with the more
traditional 555's and such. I think it could be done this way but I'm
no expert here.

by now you've seen the circuit I desiged yesterday
there were 4 and gates and two flip-flops per player plus the counter and
the clock and the or gates etc.

call it 9 ics for the whole unit including the decage counter, 4 input nor
gate (or gates) and 555 timer.

with a microcontroller you could do all of that in a single chip.

you'd need to know how to program it, and make/buy the hardware to load the
program into it (there is free software available) ...

Bye.
Jasen
 
R

Rich the Newsgroup Wacko

Jan 1, 1970
0
How about a random timeout that drops a ruler? The victim puts their
fingers near the 12" mark, and a solenoid is used to release the thing.
The score is where they grab it, in inches...

You can do this with a dollar bill (or $100, if you're feeling frisky. ;-) ).

Have the subject stand or sit next to a table, with their forearm resting
on it and their hand sticking out over the edge. Have them hold their
thumb and forefinger about 2" (50 cm) apart, and hold the bill in your own
fingers, where the middle of the bill is in between their thumb and
finger. Drop the bill.

No one can catch it.
--
Cheers!
Rich
------
"A young Juliet of St. Louis
On a balcony stood acting screwy.
Her Romeo climbed,
But he wasn't well timed,
And half-way up, off he went -- blooey!"
 
E

ehsjr

Jan 1, 1970
0
Bob said:
How about a random timeout that drops a ruler? The victim puts their
fingers near the 12" mark, and a solenoid is used to release the thing.
The score is where they grab it, in inches...

Nice!!

Plus the follow up with pointers to the parts ... great!

Ed
 
J

JeffM

Jan 1, 1970
0
Have them hold their thumb and forefinger about 2" (50 cm) apart
(Hey, I'm an American! Those damn metric things are UNNATURAL!)
Rich, Under the Affluence

Nah. The *count by tens* thing is natural enough.
It's the converting back & forth that sucks.

If we'd just bit the bullet in 1917
when the Industrial Age was hitting its stride
and the i18n thing was warming up,
it would all have been so much easier.
 
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