Addressable LEDs - QnA #2652

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1

Howdy!
I’m just looking for some clarification/reasoning behind a recent QnA, specifically #2652.

This QnA specifically addresses addressable LEDs on robots and how they are connected to the brain. As explained in the QnA response, < R27 > specifically prohibits “welding, soldering, brazing, gluing, or attaching parts to each other in any way that is not provided within the VEX platform,” with the exception for rule < R28d > "External wires on VEX 2-wire or 3-wire electrical components may be repaired by soldering or using twist/crimp connectors, electrical tape, or shrink tubing such that the original functionality and length are not modified in any way"

As recently as late last year, we’ve seen a VEX Employee talking about Aleds in the v5 system, and in previous years we haven’t really seen anyone being turned away at inspections for having these leds on their bots, even at worlds. In addition, the brain is able to fully support this!

Does anyone have an idea for reasoning behind this change? I’ve heard people try to explain that this adds additional functionality that is not included in the system (driver feedback), even though < R17b > allows SKU 276-2176 (the LED 2wire indicator). I get that the GDC doesn’t want us soldering at all, but I wish there was more clarification on why, especially if this hasn’t been illegal in the past.

This is only specifically focusing on Aleds being controlled by the brain, not leds controlled by a battery pack - allowed by < R24e >

I may be grasping at straws here :​)
Thank you!

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I forgot to mention < R24g > which allows for these leds as visual feedback, but we have no way to make them provide useful visual feedback to the driveteam, since no external microcontrollers are allowed (which makes sense), and we seemingly can’t connect them to the brain.
“Decorations which provide visual feedback to Drive Team Members (e.g., decorative lighting) are permitted, provided that they do not violate any other rules and serve no other function (e.g., structural support).”
This refutes the whole arguement for additional functionality since it seems that using lights for feedback is fully allowed.

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My personal suspicion is that they just may have received too many queries up the chain of command about its legality and placed a blanket rule in place to simplify matters.

4

What you heard is likely the reason, someone pushing the limits a bit too far, and now we can’t have nice things :slight_smile:

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Only the GDC knows why no soldering is being enforced this year, as far as I know its never been legal despite what teams may have done in the past. I’m not on the GDC and have no insight, however, I would consider non-soldering techniques and perhaps some out of the box thinking.

If you could buy an addressable led strip that was already terminated with a compatible 3wire connector that would be legal.

perhaps if you crimp a compatible 3wire connector to the cable attached to the addressable led strip it would most likely be legal as crimping smartport cables is already allowed.

perhaps the use of miniature splicing connectors such as those linked would be legal.

If you fail inspection using any of these ideas you could then, and only then, post a new Q&A.

6

Adding onto to the excellent suggestion by jpearman, these seem to be specific to LEDs and may work better. We are planning on ordering some but have not yet. These would also not require using the provided connector to the LEDs, allowing you to be able to cut the strips to the desired length and then connect to 3-wires.

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How? Would such an LED strip not have that preterminated cable soldered to it?

What exactly is the GDC banning here, and why? Is anything soldered together considered illegal as a nonfunctional decoration per this ruling? If that’s the case, then R24b is utterly pointless since cameras are guaranteed to have solder somewhere in their materials.

On the other hand, if that’s not the case and the ruling is just banning students from doing any soldering their nonfunctional decorations (oh the humanity!), then I guess I should set up a shop where I solder together lengths of LED strips with 3 wire connections and sell them as pre-terminated cables to VEX teams.

To the contrary, R27 limitations of manufacturing, attachment, etc. have historically not been applied to R24 nonfunctional decorations.
Here is a Q&A where the GDC explicitly ruled this exact scenario as legal:

@Cooper_614A even used his soldered together speaker driver electronics at worlds a few years ago (after being approved by the GDC). Heck, if we’re going to suddenly start saying that R27 applies to nonfunctional decorations, are we banning stickers next, since they utilize adhesive, which R27 specifically bans?

Welding, soldering , brazing, gluing, or attaching parts to each other in any way that is not provided within the VEX platform is not permitted.

What exactly are we trying to accomplish here? How does this improve the student experience? To borrow terminology from a certain other robotics competition, how does this new ruling make VEX more inspiring for students? Personally I thought these LED strips made robots look significantly cooler and thus increase the inspiration factor of VEX. As a former longtime competitor, and as a current longtime head referee whose job it is to enforce these rulings, I have no answers for these questions. I reached out to the GDC email more than a month ago hoping to get some answers, but got silence.

Thus, what I’m left with is a scenario where a student will inevitably show up at inspection with some cool soldered LED lights attached to their robot that clearly are nonfunctional decorations, and I get to be the one that tells them that they have to rip them all off before they can participate this year. This is disheartening and demotivating for me as a referee.

To the GDC I ask: Please reverse this decision, or at the bare minimum give the reasons behind this change, because unlike many recent well written and reasoned Q&A answers, the reasons for this one escape me.

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Charles

I think we need to leave the worms in the can.

Sometimes questions get asked that the GDC answer based on the rules of the game manual (as I understand it, again, not a GDC member here).

The old question you linked to was from 2015, different times, different GDC, not really relevant.

There was a different question from a couple of years back.

Scenario D: a robot uses an LED light strip without an RGB controller and is connected directly to the V5 brain through one or more 3-Wire ports. The V5 brain is used to set the LEDs.

That was considered legal.

VEX has an API to control addressable LED strips.

I gave some suggestions, don’t over think this.

James.

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As Mom says, “try not to break into jail”. :thinking:

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Would someone be willing to submit a Q&A asking if this style of solderless 3 wire LED connectors are legal? I wrote some text below, but our team isn’t currently registered so I can’t ask the question.

Google doc link to the same text, if that makes it easier to copy: Legality of Attaching Addressable LED Strips to the v5 Robot Brain, Without Soldering - Google Docs

Legality of Attaching Addressable LED Strips to the v5 Robot Brain, Without Soldering

In previous seasons, teams have been seen to use addressable LED lighting strips on their robot as decoration and to provide driver feedback, under Rule R24g; “Decorations which provide visual feedback to Drive Team Members (e.g., decorative lighting) are
permitted, provided that they do not violate any other rules and serve no other function”

Under Rule R8, “microcontrollers or processing devices [other than the VEX V5 Robot Brain] are not allowed, even as non-functional decorations.” Per this rule, teams previously directly soldered addressable LED strips without microcontrollers to 3-wire wires, plugged into the brain. The VEX V5 platform supports addressable LED controlled by 3-wire, as described by the official VEX API reference site; https://api.vex.com/v5/home/python/AddressableLED.html

Q&A #2652 states specifically soldering LEDs to wires or other components is not allowed under Rule R27.

Rule R28d which states “3-wire electrical components may be repaired by soldering or using twist/crimp connectors, electrical tape, or shrink tubing such that the original functionality and length are not modified in any way,” which is an exception from Rule R27e.

Provided the use of addressable LED strips is allowed for the VEX v5 Robotics Competition, if soldering to connect addressable LED strips to the brain is not allowable, would any of the following scenarios be allowable?

Scenario A: A team uses an off the shelf “3 Pin Solderless LED Light Strip Connector” as a connector between a 3-wire wire and an addressable LED strip. The brain is then used to control these LEDs.
This is not expressly allowed under Rule R20, which allows certain non-VEX components to be used.

Scenario B: A team uses tape to attach the ends of a 3-wire wire to an addressable LED strip. The brain is then used to control these LEDs.
Rule R22a allows the use of tape to secure connections between any 2 VEX cables, or Rule R22d allows the use of tape in any application that would be considered a non-functional decoration.

Scenario C: A team uses zip-ties to attach the ends of a 3-wire wire to an addressable LED strip. The brain is then used to control these LEDs.

Scenario D: A team trims and modifies the ends of an addressable LED strip to interface with a 3-wire port on the brain. The brain is then used to control these LEDs.

Scenario E: A team purchases off the shelf, pre-assembled addressable LED strips with a 3-wire connector already attached. The brain is then used to control these LEDs.

Scenario F: A team attaches an addressable LED strip using any of the fastening methods listed above, but instead of attaching said LED strip to a 3-wire cable, the strip is attached to a V5 Smart Cable. The brain is then used to control these LEDs.
Rule R21c states “V5 Smart Cables may only be used for connecting legal electronic devices to the V5 Robot Brain.”

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I was able to get them to work by putting the wire stock ends from the strip itself into the female end of a 3-Wire extension:

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and if you get answers you don’t like, then what ?

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What’s that supposted to mean? @piplup is just trying to get clarifacation.

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womp womp no leds for me :​)

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At that point I feel like soldering is much safer than that.

Random rant but since V5 got released, the robotics components switched from familiar wires with +, -, and a signal (Cortex era) to the V5 system where things clip onto place and everything can essentially turn itself into a serial bus.

Does this degree of obfuscation, like intentionally barring students from even experimenting from electronics and wiring AT ALL, go against the entire ethos of a learning platform as VEX? We are talking about people who are in high school where, if they are considering engineering, may be leaping into an educational institution where they WILL need to learn to soldier and connect things together. It would be really nice to see VEX at least give teams a couple minutes of familiarity before one jumps into a pit of pirrhanas like electrical engineering.

If the emphasis is on VEX right now is JUST computer science, there are already too many computer science students, while electrical and mechanical probably would benefit with more attention and understanding.

Maybe I am overthinking this, but what are y’all’s thoughts?