Answered: VUR7: Electronics to improve electrical reliability in VEXU

[Telemascope]

Hello GDC,

The following question pertains to VEXU, NOT VRC in which I’m fairly certain none of this is legal.

VUR7 states:

There is NO restriction on sensors and additional electronics used for sensing and
processing except as follows:
a. Sensors and Electronics MUST be connected to the VEX ARM® Cortex®-based
Microcontroller, and can only be connected via any of the externally accessible ports.
b. Sensors and Electronics CANNOT directly electrically interface with the VEX motors, motor
controllers, or solenoids.
c. The additional Sensors and Electronics may only receive power from any of the following:
i. Directly from the VEX ARM® Cortex®-based Microcontroller via any externally
accessible port.
ii. From an additional VEX 7.2V Robot Battery or from a VEX 9.6V Transmitter Battery
(only one (1) additional battery can be used for sensor power.)

Additionally, a Q&A from 2012 which I assume still stands states that for VEXU:

There are no current restrictions on what can be interfaced with the partner port of the VEXnet Joystick.

I have a few questions pertaining to this:

1. Would an electrical device used to reduce noise or power dropouts qualify as electronics used for sensing and processing (given they are designed to augment the cortex’s processing ability)? Such a device would comprise of capacitors and a TVS diode.

2. If such a device is not legal, would incorporating this functionality into a device which was also used for sensing be legal?

3. If question 1 is legal, would plugging this into the cortex motor ports be legal, or would it qualify as directly electrically interfacing with the motors?

4. Is plugging external devices into the partner joystick port still legal?

5. If so, is plugging external devices into the other ports on the joystick ,eg. the programming port, legal?

6. If so, would including a device between the input competition field control cable and the competition port on the joystick be legal, provided it could be proved that it did not alter the switching of competition modes in any way? The purpose of such a device would be to protect the joystick from static or surges on the competition control line.

7. If plugging external devices into the partner joystick port is legal, is there a restriction on who can touch/interact with these devices? I’m envisaging a situation where a non-VEXU legal driver is able to operate a robot through an interfacing device. (I assume this is covered by G2 but thought I would confirm in case anyone is desperate enough to attempt it).

Note the intent of this Q&A is to give VEXU teams the ability to sort out their electrical gremlins, not to gain any kind of other competitive advantage.

Thanks for your time,
Lucas

EDIT: I would like to add another related question:
8. Is it legal to bring your own cable to the field to plug into the field controller? If so, would it be legal for this cable to have some form of isolation or static protection provided it did not alter the switching of competition modes in any way?

[VEX_GDC]

1 - No.

2 - Yes.

3 - Yes, provided that it was the only thing plugged into that motor port (i.e. the hypothetical device is not “between” the Cortex and a motor or motor controller).

4 - Yes, provided the joystick is not modified.

5 - Yes, provided the joystick is not modified.

6 - No, this is not legal.

7 - The three Drive Team Members in the Alliance Station are the only students that are allowed to interact with the controls, per G5.

8 - No, this is not legal.