Mounting of router

[goofy173]

I just looked at the 2014 FRC Inspection List and under Robot Radio it says, "Radio must be mounted so that its LEDs are visible to field personnel" and referencing R62 The Wireless Bridge must be mounted on the ROBOT such that the diagnostic lights are visible to ARENA personnel.

Well, our electronics board is installed with drawer sliders and is located under the robot deck. My thinking is that the "radio" router is not going to be allowed underneath there. We were only worried about inspection where we could roll the board out on the drawer slides.

I think if you are at the right angle, you might be able to see the lights, but without being next to the robot until tomorrow, I won't know.

So I guess we'll have to mount it up on the deck somewhere or am I misunderstanding it?

Thanks for any input. If I don't respond it's because the internet at the school won't allow me to post here, but I can read everything. Weird but that's the way it is.

[eedoga]

Couple of things. For the Arena personnel being able to see your router makes it easier to diagnose why your robot won't connect to the field. Also, we in the past have made the mistake of mounting our router low down in our robot...Invariably this made it so that our robot would not connect to the field, or would connect, only to lose connection mid match. The robot itself provides interference making it difficult to maintain a connection, especially in a noisy environment. As a result we decided to always mount the radio higher up on the robot and out in the open if at all possible.

Hope this helps.

Edoga

[Jon Stratis]

Visibility of the router can only be for your benefit - the field personnel use it to help diagnose issues with your robot and team.

Additionally, it's a good idea to mount your router high up, away from metal and away from RF-generating sources (like the motors). Having a router buried inside a robot makes it much more likely that you'll lose connection during a match!

[TogetherSword8]

Is there any reason why you wouldn't be able to mount the router close to any other electronics, such as Crio and Digital Sidecar? Just double checking because we normally do this, and we have a track record of having more connection problems than other teams...

[Alan Anderson]

Keep the router away from electrically noisy components. That includes the Power Distribution Board, the cRIO, the Digital Sidecar, the 12v-to-5v converter, motor speed controllers, and ethernet-to-can gateways.

If you regularly mount the D-Link near other electronics, and you regularly have connection issues, take it as an indication that you should stop doing it.

[goofy173]

I wondered earlier if there could be a problem with the router and the network cable near motor controllers. I know if it was a big A/C freq drive like I work with, it could be a problem, but didn't really consider it much with these small DC drives.

Well, being that our router will now have to come out of the basement it will be away from most things. I'll have to tell them to not put it near a motor.

I also hadn't thought about connection issues. That's a good point.

Thanks for the responses.

[philso]

Originally Posted by goofy173

I wondered earlier if there could be a problem with the router and the network cable near motor controllers. I know if it was a big A/C freq drive like I work with, it could be a problem, but didn't really consider it much with these small DC drives.

Well, being that our router will now have to come out of the basement it will be away from most things. I'll have to tell them to not put it near a motor.

I also hadn't thought about connection issues. That's a good point.

Thanks for the responses.

From having spent many hours in an EMC test lab, I definitely recommend you take Alan's advice. I sometimes view the AC motor drives I do R&D on (88-2000 hp) as noise generators that are their own worst enemy.

[DonRotolo]

Remember folks, it is still a radio. The antenna needs to be as far away from any other metal as you can reasonably make it.

[goofy173]

I made my feelings known today, and to no avail, so if there is a problem, I'll stand back and say, "Told ya so" and go from there.

The lead mentor believes that as long as the field person can come out to the robot and see the router lights without too much trouble, we'll be OK. I'm going to have the kids mount the router at an angle so that it can be seen looking down into the front, just above the bumpers. If inspection says something about that, then again I can say, "Told ya so."

I am fighting the shop right now because they wanted the electonics on a drawer, and both times it was test fit, it didn't. The first time they forgot to take into account the height of the cRIO. This time new items they mounted on it blocked the drawer from even starting to slide in, so they rotated the drawer 180° and although it still didn't fit, they want that. So now all the electronics have to be removed and installed differently, and where I was told we could run wires from side to side, is now not available for wires. All this and they expected a running robot today. Very frustrating for me being a rookie mentor.

I just told the kid in my electronics team that I will be there when they try and blame us for any problem or being late, and I will remember that the shop changed everything for us twice (so far). The mentor in charge of the build (also a rookie) complains about a lack of communication between teams. I guess he feels that being in charge of the build means he doesn't have to communicate with anyone.

After 27 years of being in a union shop, I'm used to getting blamed, so its no big deal to me at all. I'm just going to go to bat for my students because they've done everything they've been asked to do.

[philso]

Sorry to hear about your trouble with "office politics". Your students are getting an early look at what they are likely to have to face in the future. Hopefully, your students will understand why you are telling them to do certain things like "communicate frequently and clearly with the other departments".

[DonRotolo]

If it were me, I'd be sure to print up a few cards that say "I told you so!", so when it happens at inspection (and it will), you can hand them out.

To help your kids manage the stress when they fail inspection, have them think of exactly how they are going to fix it, and make up all (or many of) the wires, brackets, and things they'll need to do it in the pits.

[Alan Anderson]

Originally Posted by goofy173

The lead mentor believes that as long as the field person can come out to the robot and see the router lights without too much trouble, we'll be OK.

Please let the lead mentor know that many people with years of experience as FRC technical advisors say to put the wireless bridge out in the open. Not just because it keeps the lights visible, but because it is a radio transceiver. If it's surrounded by enough metal and electrical components to make it hard for a person to see, it'll very likely be hard for the field's wireless access point to "see" it too.

[goofy173]

I said to him, "So we to are ignore those that posted that they've had problems?" His response was that it's hardly metal 'cause it's aluminum. I believe he has expertise in networking, but I honestly don't know how much.

I've had an offer for me to take a pic tonight and it be shown to a chief inspector and at least I'll know if its ok to be almost hidden.

I'm also having the kids leave enough power wire, held by a tie wrap, so that it can quickly be mounted on the deck. I asked for a hole thru the wooden deck in case, but I know that will be ignore.

I don't push my knowledge and electronic degree on the other mentors if they decide that things are to be done a certain way. I figure they should know more about building the robot and the rules than me. I think new blood is not always appreciated.

[Ikillee]

Can the router be placed on top of the battery? That's the best place we got where the router is the least interfered with. Other places are underneath our polycarbonate in the middle of all the electronics. My team doesn't want to agree with mounting on top of the battery because the battery could overheat or something.

[Al Skierkiewicz]

Ikillee,
During match play, the battery might get hotter than normal. It also contains a lot of metal. I would think you could find a better place. If it is on top of the battery, don't you have to remove it to change batteries? You don't charge batteries in the robot do you?