Official Q&A: VEX V5 Robotics Competition 2025-2026: Push Back

R28d states:

“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.”

R21c states:

“V5 Smart Cables may only be used for connecting legal electronic devices to the V5 Robot Brain.”

R8 states:

“Robots must ONLY use one (1) VEX V5 Robot Brain (276-4810). Any other microcontrollers or processing devices are not allowed, even as non-functional decorations.”

Teams have been seen to use addressable LED lighting on their robots. Per R8, these lights must be controlled by the v5 brain if they are to be legal (otherwise the LEDs would be controlled by another microcontroller). Beyond that, there is not explicitly clarity on how to evaluate the legality of such a nonfunctional attachment to the brain. To connect these LEDs to the brain, teams could either use a smart port or a 3-wire port. Per R21c, a smart port does not appear to be a legal attachment method, as the attached LEDs are not a “legal electronic device”. Alternatively, a team could use a 3-wire port to attach the LEDs. R28d explains that 2-wire/3-wire cables may not be modified in such a way that additional functionality is added, which sounds like any attempts to solder an LED strip to a 2-wire/3-wire cable would be illegal (as this new interface created by soldering would add additional functionality). Here are some foreseeable scenarios, which ones, if any, would be legal?

Scenario A: A team snips off the end of a v5 smart wire, and solders an LED strip to this wire. The wire is then connected to the brain to control the LEDs.

Scenario B: A team solders the LED strip to breadboard jumper cables, or a similar wire that could make contact with a smart wire. The team then tapes (or similarly fastens without soldering) these wires to a smart port or the end of a smart wire. The brain is then used to control these LEDs.

Scenario C: A team snips off the end of a 3-wire (or a 2-wire) cable, and solders an LED strip to this wire. The wire is then connected to the brain, or a 3-wire expander, and the LEDs are controlled by the brain.

Scenario D: A team solders the LED strip to breadboard jumper cables, or a similar wire that would fit into a 3-wire port. The team then inserts these wires into the brain, such that the brain can control the LEDs.

Scenario E: A team solders the LED strip to breadboard jumper cables, or a similar wire that would fit into a 3-wire port. The team then inserts these wires into a 3-wire/2-wire extension cable, and plugs that cable into the brain or a 3-wire expander. The LEDs can then be controlled by the brain.