MXP Ethernet Switch

[Richard.Varone]

So a post in the new Radio thread got me thinking ( and designing ), and I have a few questions.

How much interest would there be for a MXP 4 Port Ethernet Switch?

How much interest would there be for a MXP 4 Port Ethernet Switch with additional processing power ( CPU/FPGA )?

How much interest would there be for a MXP 4 Port Ethernet Switch with additional features ( please list wanted features )?

Thanks

[marshall]

Originally Posted by Richard.Varone

So a post in the new Radio thread got me thinking ( and designing ), and I have a few questions.

How much interest would there be for a MXP 4 Port Ethernet Switch?

How much interest would there be for a MXP 4 Port Ethernet Switch with additional processing power ( CPU/FPGA )?

How much interest would there be for a MXP 4 Port Ethernet Switch with additional features ( please list wanted features )?

Thanks

I actually don't think this is a worthwhile endeavor but don't let that stop anyone from trying. If it works out and makes sense then we might be interested in it. That being said, here are my reasons why I don't think this makes a lot of sense:

There are ethernet switches available already that run off of 5v and 12v and draw less than 1A of current: http://www.amazon.com/gp/product/B002HH0W5W

The MXP boards are typically screwed down to the roboRIO, which is then typically firmly attached to the chassis. People yank on ethernet cables. They have tabs to stop them from being pulled out. If someone were to accidentally yank on a cable coming off of an MXP board on the RoboRIO then that would be not so good for a lot of reasons.

The weight savings is minimal for this compared to just using a more common switch.

You can't pass ethernet traffic over the MXP port without some serious voodoo.

There is likely a very small market for this product. My guess is less than 2% of all FRC teams. That's less than 80 teams.

There's no real gain from drawing power from the MXP port instead of just pulling from the chassis directly.

Any additional features have to fit within an already crowded footprint space.

Extra sensors and things like CPUs might require shielding from the magnetic couples on the ethernet jacks and just draw more power on the RoboRIO.

Again, don't let me deter you. Prove me wrong. Make this and make it work somehow. Someone tell me why it will work.

[Richard.Varone]

Just a little background, I work for a company that builds rugged compact low power modular systems for the defense and aerospace industry. We already make very low power and compact ethernet switches with integrated processing power.

How I imagine my team using this product would be RoboRIO Ethernet -> OM5P-AN -> MXP Ethernet switch, our camera(s) and tether would connect to the the MXP Ethernet, our vision processing would take place on the integrated processing power ( CPU/FPGA ) and then talk to the RobotRIO through either/both the SPI/DIO on the MXP and Ethernet.

I'm not necessarily looking to make this a "business", so the small market isn't really that much of a concern to me, but I wouldn't be opposed to it .

Edit: Btw I appreciate the comments/concerns, but unless this project is somehow deemed illegal by 2016 rules, I'll be working on this for my team regardless of other's interest as a product, I'm just curious if anyone else would be interested in this or something similar as well.

[marshall]

Originally Posted by Richard.Varone

Just a little background, I work for a company that builds rugged compact low power modular systems for the defense and aerospace industry. We already make very low power and compact ethernet switches with integrated processing power.

How I imagine my team using this product would be RoboRIO Ethernet -> OM5P-AN -> MXP Ethernet switch, our camera(s) and tether would connect to the the MXP Ethernet, our vision processing would take place on the integrated processing power ( CPU/FPGA ) and then talk to the RobotRIO through either/both the SPI/DIO on the MXP and Ethernet.

I'm not necessarily looking to make this a "business", so the small market isn't really that much of a concern to me, but I wouldn't be opposed to it .

Edit: Btw I appreciate the comments/concerns, but unless this project is somehow deemed illegal by 2016 rules, I'll be working on this for my team regardless of other's interest as a product, I'm just curious if anyone else would be interested in this or something similar as well.

Rock on! Like I said, don't let me stop you. I think this would be cool if it could be done. It's definitely an interesting notion.

Edit: Also, I don't know if it got through from St Louis last year but I work with the son of one of your mentors, Mr Culotta. It's proving to be a very small world today for me.

[AllenGregoryIV]

I don't really see a huge use for this either. The NavX right now seems like the most useful MXP board to me and since there are other switches and co-processors I can add easily, I don't see us using it. Like Marshall if it's something you think you need, it could be worthwhile for others too.

[nuclearnerd]

Originally Posted by AllenGregoryIV

The NavX right now seems like the most useful MXP board to me...

No reason why more than one mxp board can't stack like arduino shields, is there?

[TheHolyHades1]

Originally Posted by nuclearnerd

No reason why more than one mxp board can't stack like arduino shields, is there?

Speaking of which, maybe an arduino MXP board?

[Richard.Varone]

No reason why more than one mxp board can't stack like arduino shields, is there?

This is a great idea, with what I'm thinking, it would be possible to stack almost any other MXP board on top of the ethernet board I'm thinking about.

Originally Posted by TheHolyHades1

Speaking of which, maybe an arduino MXP board?

Rev already makes this:

http://www.andymark.com/product-p/am-2996.htm

[GeeTwo]

Some of the questions appear to indicate a poor understanding of the valid vs invalid uses of MXP, so I'm just going to throw out a calibration here:

Assuming the rules for 2016 match the rules for 2015 (usual caveats, but I'd put the odds at 75%+% for this point this year), MXP boards that only interface to sensors, data feeds, computing resources, or decorative lighting are good to go, without certification. Likewise, any MXP board that is entirely passive (has no electronics or computer function, but consist of conductors designed to faithfully replicate signals sent from the 'RIO) is probably good to go. Anything that actuates or similarly interfaces with a motor controller or other actuator that is not equivalent to a bundle of wires needs to be vetted and approved through FIRST to be approved for use. Last year, I was aware of no a device which interfaced "intelligently" with sensors while interfacing "passively" with actuators, but I expect that such a hybrid device would have been put through the active device approval process.

There is a serious potential weirdness in the use of MXP to host an ethernet switch. A network camera is obviously a sensor. A network raspberry pi that does vision processing but touches no manipulators is also demonstrably acceptable. Unfortunately, there are a great number of network devices that perform communications illegal for FRC, or actuate real-world devices. Exactly where the GDC will come down on this is completely up for grabs. Based on past performance, I'd put the likelihood that the GDC will allow network-through-MXP communication with other CPUs, even if it just consists of data processing, at a bit under 50%. That is, they seem to prefer to err on the side of being too cautious rather than being too permissive. That's just the sort of stuff happens when you put a bunch of engineers on a committee. (Not a complaint, but an observation.)

[nuclearnerd]

Originally Posted by GeeTwo

MXP boards that only interface to sensors, data feeds, computing resources, or decorative lighting are good to go, without certification. Likewise, any MXP board that is entirely passive (has no electronics or computer function, but consist of conductors designed to faithfully replicate signals sent from the 'RIO) is probably good to go.

The proposed switch would not use any of the MXP pins except power. As such, I would not expect it to be subject to RIO regulations (although I've been surprised by rulings before.)

[GeeTwo]

Originally Posted by nuclearnerd

The proposed switch would not use any of the MXP pins except power.

That's not how I read some of the posts above (emphasis mine):

Originally Posted by Richard.Varone

How much interest would there be for a MXP 4 Port Ethernet Switch with additional processing power ( CPU/FPGA )?

How much interest would there be for a MXP 4 Port Ethernet Switch with additional features (please list wanted features)?

Originally Posted by Richard.Varone

How I imagine my team using this product would be RoboRIO Ethernet -> OM5P-AN -> MXP Ethernet switch, our camera(s) and tether would connect to the the MXP Ethernet, our vision processing would take place on the integrated processing power ( CPU/FPGA ) and then talk to the RobotRIO through either/both the SPI/DIO on the MXP and Ethernet.

Originally Posted by TheHolyHades1

Speaking of which, maybe an arduino MXP board?

[electroken]

Originally Posted by TheHolyHades1

Speaking of which, maybe an arduino MXP board?

I'm just finishing up an MXP design that adds an Arduino Micro and a 5V, 2A power supply to our MXP design from last year.

Gotta have Neopixels...

[jds2001]

I don't want to dissuade anyone from anything, but I'd like to draw attention to R58 from last year:

If a motor or servo is controlled via the MXP, it (or its power regulating device) must be connected by one of the following
methods:
A. directly to any PWM pins,
B. via a network of PASSIVE CONDUCTORS used to extend the PWM pins, or
C. via one approved ACTIVE DEVICE:
a. Kauai Labs navX MXP
b. RCAL MXP Daughterboard
c. Rev Robotics RIOduino

I can find precious little other information on ACTIVE DEVICES with a quick search, but I seem to recall that they were prohibited last year except for the 3 above (though the wording of that rule seems to indicate that was only if motors were connected through it)

I'd tread carefully on investing significant amount of time/money into this before we know the rules for this year, and what will be allowed to connect to the MXP.

[AustinSchuh]

Originally Posted by nuclearnerd

The proposed switch would not use any of the MXP pins except power. As such, I would not expect it to be subject to RIO regulations (although I've been surprised by rulings before.)

Be aware that the MXP power isn't very good power. It browns out soon after the motors brown out. I would expect to see it go much more often next year.

[FrankJ]

Obviously this is going by 2015 rules. A minor assumption that 2016 rules in area will be similar. An Ethernet switch would considered an active device. Completely legal if you are not controlling motors or servos via the MXP port. If you wanted to use the MXP for motors & servos the board would have to be "approved" even if the outputs pins were a simple pass-thru or even on a different header.