Ethernet port on robot
 

Ok, so my electrical peeps have posed a question and before I say ok I would like to know if anyone else has tried this.

They want to mount an Ethernet port on the bot. The Ethernet cable on the backside would lead to a port on the cRio and be 'permanently' connected (i.e. there would be no need to plug and unplug this cable from the cRio).

The idea is that when the coders needed to upload code they would do so through this port instead of having to, 'reach inside the bot where there are sharp pointy things that can poke and scratch the coders' sensitive hands.'

I have searched CD and have not seen where anyone has done this and according to the peeps interpretation of the rules this would fall under a 'custom circuit'.

I have told them that I was first going to check CD and then post in Q&A before I would consent to their experiment.

Thoughts?

Re: Ethernet port on robot
 

Not sure if this is what you mean, but last year we ran an Ethernet "pigtail" (male to female) from our radio to an easily accessible spot for ease of access to a port. Worked quite well at competition.

Re: Ethernet port on robot
 

Maybe...ok, I see what you're talking about (thank you Google). What they are actually talking about is the wall-jack itself (like you see in a wall where you plug in your Ethernet cable. In their minds they would physically wire the jack themselves with the RJ-45 end plugged into the cRio and the port available for plugging in the computer.

What you guys implemented is makes more sense logically.

Re: Ethernet port on robot
 

If you're concerned about it working properly: it should be fine. We've used similar setups for the same reason over the years, and they've worked well.

If you're concerned about rules: a) you won't be connecting from the ethernet port to a computer during competition unless you are changing code at competition. b) R56 says that the wireless bridge may be connected via a pigtail, which is what it sounds like you are using.

Either way, you should be fine.

Re: Ethernet port on robot
 

Thank you for the quick replies :]

Re: Ethernet port on robot
 

How would the radio be connected to the cRIO in this scenario?

Re: Ethernet port on robot
 

you can have a spot where the pigtail is out of the robot. Ie what spectrum did in their drive train during the off season. This allows for an easy remove/install for the cable. See http://www.chiefdelphi.com/forums/sh...d.php?t=119581 they did what I think you are speaking of.

Re: Ethernet port on robot
 

I would put the pigtail in the router if your using the crio II.

Re: Ethernet port on robot
 

I would recommend doing this not only on your robot but your driver station as well. That port gets frequent use and my team had actually experienced the Ethernet port on the laptop fail causing us not to move in a match. Here is a company associated with FRC that sells the one that we now use https://www.estoprobotics.com/estore...d&productId=27

Re: Ethernet port on robot
 

Agreed. We beat up our Classmate ethernet pretty badly, so when we got a new laptop, we made sure to use a pigtail for the connection.

There are enough things that can go wrong without worrying about the ethernet port...

Re: Ethernet port on robot
 

Can we have the radios on in the pits? I thought not but maybe that is an old rule. We always hook up a little 4-port bridge for pit access - that way we can hook up the cRIO, tether the DS and connect a code development laptop.

Re: Ethernet port on robot
 

In 2012, we used one of these port savers to easily connect to the robot, since the ports all pointed down on the radio in a most-inconvenient way.

As to radios in the pits:

Re: Ethernet port on robot
 

We've had an externally available port for a number of years. Typically we do it with a female-female connector designed to be mounted through a surface - just cut out an appropriate rectangle in one of the lexan shields, push it in until. It clicks in place, then hook it up permanently to the radio using a short Ethernet cable. The benefit of this over a wall jack is that you don't have to mess with the wiring - just use standard cables and it all works out. I hate cutting open an Ethernet cable and having to figure out where all 8 wires go!

Re: Ethernet port on robot
 

You can have the D-Link powered on in the pit, as long as you leave it in Bridge mode and don't try switching it to AP mode. You are encouraged and expected to leave everything connected on the robot, and plug in your programming computer and/or Driver Station using an available D-Link ethernet port.

Re: Ethernet port on robot
 

Which is what we have typically done. I am not sure where they are talking about burying the router that this is necessary (we have not fully discussed their reasoning yet as they proposed this close to time to go home last night). They just kept saying, 'but it would be soooo much safer'.

Thank you to everyone who responded and we will take your suggestions under advisement.

Re: Ethernet port on robot
 

It is safer... a few years ago before we started doing this, our programming team managed to bust enough of the ports to kill 2 radios, just through practice/test while tethered on the practice field. With an adapter in the middle (properly supported, of course), you'll bust the adapter, not the radio - and the adapter only costs a buck or two.

Re: Ethernet port on robot
 

Last year we tried something new with great results. We ran a wire to the back of the robot, nearest the programmers in the pit, and used a punch down network jack. We velcro-ed it down. We have always had problems in the past with people tripping over the wire and breaking something important. With this method they just yank out the punched down wires, which can be quickly punched down again.

Re: Ethernet port on robot
 

Yikes - We have been too restrictive in the past. Thanks Alan! Your posts are always most helpful.

Re: Ethernet port on robot
 

FWIW, burying the radio is probably a bad idea apart from the Ethernet cable(s). You have to take it out to have it programmed with the security key for the event, the lights are supposed to be visible when on the field, and it may not work as well when surrounded by metal and/or near things like motors and the power converters...

Re: Ethernet port on robot
 

This is more of a bad idea from the standpoint of connectivity than that of damage. The AP has two antennas that communicate with the field wireless router. It needs both of the antennas in the clear, away from noise generators and metal, to maximize bandwidth connection in both directions. Low and inside is good for baseball and bad for the AP.

Re: Ethernet port on robot
 

Which makes sense as we have had unexplained connectivity issues in the past which in turn taught us to mount the radio in more clear spaces.

Our design is very similar to Boom Done with a vertical backplate. The router is to be mounted toward the top of the backplate behind the catapult arm.

Two students are full steam ahead to implement the idea. Engineering mentors have said that this is not necessarily a bad idea. I just am having a hard time seeing it's purpose in our current design. On some of our other bots, maybe, just not necessarily this year's bot.

My contention is that you should never plug and unplug the programming computer from the router or cRio when the robot is powered. Period. Turn off the robot, disconnect the battery and then plug and unplug from the router. Or do I not correctly understand how code is uploaded and transferred?

My primary issues were legality (which has been answered here) and whether or not it had been done before.

Re: Ethernet port on robot
 

There's no need to turn everything off to plug in or unplug a ethernet cable. You can leave the robot running and upload code as many times as you want, you just may need to occasionally reboot the cRio.

The real use for a port like this is for the practice field. If you're driving the robot around while it's tethered, or attempting to test autonomous, it's possible (even likely?) that the ethernet cable will get yanked at some point. Even in your pit, it's possible for someone to trip over it. When that happens, you don't want it to break the ports on the router!

Re: Ethernet port on robot
 

If you have sharp pointy things that can poke/scratch hands, they ought to be dealt with. It's an inspection checklist item and I'm surprised Jon and Al didn't already make mention of this!

Your electrical team has sensitive hands also, as do your inspectors.

That being said, it still adds convenience for reasons previously covered, and prevents programmers from disrupting things when reaching into the bot, even if those things are now non-pointy.

Re: Ethernet port on robot
 

My apologies, let me clarify; from a safety standpoint I have always told my students that they are not to ever place their hands within the frame of the robot while it is powered up. Let it destroy itself if it goes haywire but not my children's hands (or other appendages for that matter). And as far as the 'sharp pointy things' yes those will be taken care of prior to competition I promise :]

The first year I participated in FIRST a safety incident was posted here on CD regarding a child who lost a finger at another regional because they thought their code had completed its cycle. That may have made me a little paranoid regarding sticking hands and fingers inside the bot while it is powered. Unplugging the battery is just an added precaution that the robot is not going to eat anyone.

I can see the argument for the port on the practice field. Like others we have a Classmate who has a port issue due to a short Ethernet cable. I just had never heard of the pigtails being used.