Elbow rule help

Ok, I'm fairly new to arduino but at the same time, I do understand a lot about it.
I am currently building a beer pong table, and just from previous knowledge, everyone, everywhere playing the game complain about the elbow rule.

This being said, I'd like to use arduino to help with this problem. Basically bringing technology to game.

For those of you that don't know in the game,using the elbow rule when shooting the ball on ur turn, your elbow can not cross the table vertically. (or else reshot or loss of shot)

Now I would like to have something that one could wear around their elbow area and be deteced when crossing the table, then possible using the arduino to make leds go off or play sound or something.

I just don't know at all what to use for the whole elbow thing. Any suggestions?

You could use a laser pointer, photo resister, and a buzzer to make a laser tripped alarm along the edge of the table.

How exactly would this work? keeping mind that upon shooting, from the elbow to the end of the fingertips, and ball will be crossing the table

Any suggestions?

String. Tie one end around the shooters elbow. Tie the other end to the wall right behind the shooter. Ensure the string is the exact length to prevent crossing over the table.

As an added bonus, the shooter end could be replaced with a choke-chain ensuring the shooter does not violate the rule.

]:smiley:

[quote author=Coding Badly link=topic=64004.msg465866#msg465866 date=1308106633]String. Tie one end around the shooters elbow. Tie the other end to the wall right behind the shooter. Ensure the string is the exact length to prevent crossing over the table.

As an added bonus, the shooter end could be replaced with a choke-chain ensuring the shooter does not violate the rule.
[/quote]

umm... Thanx

Really hoping for a serious answer.

Sorry if I didn't explain well enough. Here's a picture I found.

The elbow can go over the table

Scratch the laser idea, I thought that the entire arm was staying behind the table.
Another idea which is too expensive involves strapping an arduino to every elbow with a IR sensor and a buzzer on it. There would be an IR led under the table. If the sensor loses a signal then the arduino makes a buzzer buzz.

I was thinking the same concept, except one arduino on the table with some sort of powered ir led on the elbows, but the problem there, is that whose to say the led would always be pointing straight down.

Something said earlier got me thinking. Thinking of like security towers in stores, is there anything I could put on the table or even poles on the ethier side of the table, (or antennas), do detect when like a tag passes. (without spending way more than what the idea is worth)

I haven't worked with RFID before but do some research on it. I think they have sensors on either side, so on the table and on the ceiling.

A reflective band on the arm just below the elbow, one of those lasers like they use on automatic levels that will trace a line and then sense the reflection of the band when it crosses the laser line.

I've been looking at the all that with the tags and havnt been getting anywhere. Especailly because energetic with Arduino I've found has a very short range

Good idea with the laser though. I like it. Any suggestions on what to use to sense it? Or even laser
I'll be looking

I've seen them on laser levels at homeowner stores. I have one somewhere. Basically they are a laser that passes through a lens that makes the beam into a line. The line is actually fun to play with. To sense it get a sensitive photoreceptor. I bet some of the folks on here can suggest something. If you could go infrared, there would be less interference, but you couldn't see it. IMHO, seeing it is part of the fun.

Actually, you could put a reflector on them that is roughly the same color as the laser and it will light up like a spotlight when they cross the line. Similar to what happens when you point a red laser at the tail light of a car.

google laser levels and go from there for a ton of ideas.

Ok been looking for reflective sensors, but everything I'm finding is pretty short range...

Anyone have any suggestions?
Also keeping in mind the goal is to sense a reflection over a 2ft wide area (so a direct line really wouldn't work) and say a few feet high.