Ethernet port on robot

[Jon Stratis]

Originally Posted by rsegrest

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.

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.

[fsgond]

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.

[wireties]

Originally Posted by Alan Anderson

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.

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

[nuttle]

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...

[Al Skierkiewicz]

Originally Posted by rsegrest

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'.

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.

[rsegrest]

Originally Posted by Al Skierkiewicz

This is more of a bad idea from the standpoint of connectivity than that of damage...It needs both of the antennas in the clear, away from noise generators and metal, to maximize bandwidth connection in both directions.

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.

[Jon Stratis]

Originally Posted by rsegrest

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?

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!

[jvriezen]

Originally Posted by rsegrest

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.'

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.

[rsegrest]

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.