Hello,

My buddies and I play a decent amount of Cornhole, and we have a shorter playing area so we came up with a rule that your elbows cannot cross a certain point of the board, to try and keep it challenging to play. I thought it would be an interesting project to try and design a simple device that would alert people (alarm, LED, etc) if someones elbow crossed the set point. I know it may be hard to design something that would test at all possible points on the plane that cannot be crossed, but to start simple, say I only need to test at one point on the plane. I have tried to look for devices that may test at this range that are compatible with an Arduino Uno, but it will be hard to differentiate forearm from elbow. My next thought was to use a reflective armband of sorts that when crossed the sensor, the sensor would recognize that the armband is past the point. I am unfamiliar with any of these sensors and I am curious if anyone else has any ideas for this, or knows of any current sensor/band combos that can be used, any info would be greatly appreciated!

Thanks for the help!!

 

It's an interesting problem.

I had to go look at what table top cornhole actually is and it is confusing. You mean tabletop like this one:

Or a coinhole variation like this one:

Either way, since you can place your hand and arm over the "foul line" but not your elbow, you can forget about the easy beam break methods and it look like you have.

I don't know, but it seems like wearing an armband is a good approach. If a detector is on the table and an emitter in the armband, an IR sensor might work but the elbow fault needs to right on top of the sensor. A magnetometer as a proximity sensor might offer something. Maybe even a capacitive proximity sensor.

As I am typing, however, I think your reflective idea might work. An emitter and detector on one side of the table and the elbow armband reflects the beam back to the detector.

A gesture sensor that only sees the elbow armband might be cool - but how?

Ultrasonic emitter on the elbow with a narrow band detector on the table?

Let us know what you try.