IR Jamming from 2 or more remotes - results

[Joe Ross]

In our tests, we could get a command in every few seconds with 1 remote jamming, but not with two.

[Alan Anderson]

Originally Posted by Matt H.

As your alliance partners are all pointing their remotes right where you are pointing your you may end up not able to do anything.

You wouldn't be aiming your remote at your alliance partners' robots. Why would they be pointing theirs at yours? And if you narrow your sensor's field of view enough, only one remote will be visible to it anyway.

I think I'll suggest mounting our IR sensor near the floor, with a shield above it. Only someone holding a remote a few inches off the ground should be able to get a command through to it.

[Matt H.]

Your alliance partners start the match very close to your robot--It would require a very directional sensor on everyone's part not to be pinging other peoples robots.

[Alan Anderson]

Originally Posted by Matt H.

It would require a very directional sensor on everyone's part not to be pinging other peoples robots.

Something as simple as a paper towel tube ought to suffice. Consider bringing a handful of them to the field and handing them out to your alliance partners if it looks like they'll be spraying IR all over the place.

[Daniel_LaFleur]

Originally Posted by Alan Anderson

Something as simple as a paper towel tube ought to suffice. Consider bringing a handful of them to the field and handing them out to your alliance partners if it looks like they'll be spraying IR all over the place.

Shhhhh .... dont tell them our secret

I toilet paper roll tube for the robot ... 50 cents and Cots (once roll is used )
1 paper towel roll tube for robocoach ... 50 cents and cots (again once roll is used )
Being able to block all IR but your own for the initial command ... priceless

[Bongle]

Originally Posted by Daniel_LaFleur

Shhhhh .... dont tell them our secret

I toilet paper roll tube for the robot ... 50 cents and Cots (once roll is used )
1 paper towel roll tube for robocoach ... 50 cents and cots (again once roll is used )
Being able to block all IR but your own for the initial command ... priceless

I'm not sure this is necessary though. If you're only going to send an initial command, simply mounting the IR on the back of the 'bot and having your robocoach stand at the station behind it would be sufficient. At that point, you're only competing with alliance partners for signalling, so you can just tell them "hey, I just have one signal to send". Plus it would give you a bit more flexibility to signal it once it has moved. A TP tube over the sensor would make it so directional you'd ONLY be able to signal at the beginning.

[joshyboy9987]

So, what about something that's not IR? But I guess this isn't the point...

I was thinking that you could use a ultrasonic device to send a pulse for the robot to listen for impulse during that pulse. That way it wouldn't get signals from other robots, and you wouldn't have to waste CPU time listening... Also, with ultrasonics, you can apply electronic filters on them, which means that you can choose to only accept your frequency.

Another thing I've read on some other posts is that you could use a gyro to make the IR detector always point toward the Robo-Coach. I suppose a electronic compass would work for that too (are we allowed to use those?)

Even though, I've been toying with the idea of not even using the hybrid part at all... That would make IR signals irrelevant...

[MiniNerd24]

Uhhh... I'm probably wrong but are you allowed to purposely jam the others signals? I thought that was illegal. (TEASER: Well with our modification jamming won't be a problem. )

[nparikh]

Originally Posted by MiniNerd24

Uhhh... I'm probably wrong but are you allowed to purposely jam the others signals? I thought that was illegal. (TEASER: Well with our modification jamming won't be a problem. )

Good to hear that you've found a way to eliminate jamming! I don't think that many teams will intentionally jam the field, but interference may definitely be an issue. Looking forward to seeing how it works!

[Mr. Lim]

Originally Posted by MiniNerd24

Uhhh... I'm probably wrong but are you allowed to purposely jam the others signals? I thought that was illegal. (TEASER: Well with our modification jamming won't be a problem. )

Not as worried about intentional jamming, but:

A RoboCoach who holds down a button continually, or hits it repeatedly will jam others. Intentional or not.

If you're a RoboCoach, you hit a button and it doesn't work right away, what will you naturally try and do? Chances are, you will either hold it down, or press it as fast as you can, possibly jamming the RoboCoach beside you.

Guess what the RoboCoach beside you will try and do now that their buttons don't seem to be working?

This thread has a couple of good solutions, but it looks like it'll be a combination of many things to effectively get around this. Adjusting scope of IR emissions, adjusting scope of IR reception, and the all important social engineering between RoboCoaches.

Make sure your RoboCoaches know the ins and outs of your robot's IR requirements! I'm calling it now, you WILL run into more than one team (alliance or opponent) whose Hybrid mode will depend on sending continuous IR commands to their robot.

Be prepared to deal with it - in a GP manner of course =).

[GGCO]

Unless you buy some really really really unpopular remote I am 100% sure that we are going to encounter interference.

I recommend trying to depend on the IR board as little as possible.

[JesseK]

It would seem that this IR jamming problem could become irrelevant if you adjust your designs and strategies. For teams attempting to complete a full lap and/or knock their trackball off of the opposing alliance's overpass, things will be extremely complex to avoid interference.

However, for your own side/alliance, there's a pretty easy solution: coordination. If you can "point" your cardboard tube back at your own alliance station as you're driving away, then simply coordinate a system of yelling out to your alliance partners when you're signalling. Especially if you discern a sequence of who goes first after the trackballs are placed, you'll be ok. For elims I can see this being a common practice with much synergy, but for normal matches probably not unless you have a very understanding alliance.

As the ultimate symbol of GP, to come back on the opposite side, you can have your robocoach who's on the opposite side of the field coordinating with the opposing alliance. This WILL come full circle if you do, as they will probably very graciously have their robocoaches on your side return the favor.

Actually, after thinking about how the field and robocoach stations are setup, you can really design this to where interference with/from your opponents is ALL a moot point since IR is directional with some refraction. I'll have to post a drawing later some time.

[rjmah]

I believe it would be best to have an optically focused beam. Paper tubes on the transmitter will be of limited use.

The tsop34838 receiver has AGC in the circuit. You just need more of your signal to show up at the receiver than ambient noise. I haven't finished building it yet but the plan is to use an old flashlight reflector and put the IR LED in the "sweet spot" for a nice parallel beam. Has anyone tried this?

It should be the same as having a signaling remote 5 ft. away versus an interfering one at 10 feet away from your detector.

[Devibeast]

IR is definitely going to be..... interesting. Something or another is going to be jamming the signal, with all six teams on the field god only knows how the match is gonna turn out.

[MiniNerd24]

So yeah after days of planning we went with no anti jamming device and a short range remote...this is going to be an interesting match.