How to get more 12v pins on robot?

Hey all!
I’m looking into doing a lot more electronics stuff this year (arduino LED control, network switch, pi4 for better video encoding, probably other things) and I realized that we won’t have enough 12v 2A pins on the VRM. We plan on filling up the PDP with motors for a belt system and other things, so we can’t just hook up another CTRE VRM to one of those. I have seen references to other voltage regulators with more available pins, can someone direct me towards one of these that works well?
Thanks!

Just a note, per R33, you can use USB battery packs to power co-processors, etc.

COTS USB battery packs with a capacity of 100Wh or less (20000mAh at 5V) and 2.5 Amp max
output per port, or batteries integral to and part of a COTS computing device or self-contained
camera (e.g. laptop batteries, GoPro style camera, etc.) may be used to power COTS computing
devices and any peripheral COTS input or output devices connected to the COTS computing device
provided they are:
A. securely fastened to the ROBOT.
B. connected only using unmodified COTS cables
C. charged according to manufacturer recommendations

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According to R47, the VRM connected to the VRM/PCM plugs on the PDP, (which has your radio connected to it) cannot have anything else connected to the 12V 2A output (excluding radio ofc).

Also, the 2x 12V 2A outputs on the VRM share the 2A limit, so in essence there is only 1x 2A output if you use the full 2A.

As far as I am aware, if you want more 12V regulated outputs, you will have to sacrifice one or more of your PDP outputs. However R52 allows you to have 3 VRMs connected to 1 PDP port, provided your wiring complies with R49.

Should you want even moar power, I’m not aware of any rule that prevents you from using your own regulator with a higher rated output, so long as it complies with the rest of the rules. My understanding is that it would be classified as a Custom Circuit.

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Just a note, per R33, you can use USB battery packs to power co-processors, etc.

Oh, that might be a good solution, thanks!

That’s good to know, I’ll see if I can negotiate with engineering for another PDP slot lol

Any recommendations on what to use specifically? I’ll see if anything is on Amazon, but the 3x VRMs is probably the best bet.

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Keep in mind each pack is still only allowed to be capable of 2.5A, so if you are using the full output you will need multiple packs. All of which have to be charged between matches.

Also keep in mind R33-B

B. connected only using unmodified COTS cables

Meaning you can’t make your own cable to connect the device.
Since it must be a USB battery pack, you then need to use a USB cable. Fine for Arduino/RPi so long as you prevent the cable from falling out.
However for a network switch you will need to find one that takes power over USB, or a COTS USB-To-Something cable.

Also, another thought, these power packs being USB are probably 5V.

Anyone feel free to correct me if I’m wrong here!

I would certainly recommend using your own regulator connected to the PDP. I’ve not actually done this and so don’t have any recommendations.

We’ve used these (or something similar) for powering rpi’s, Jestons, LEDs, and other “custom” electronics. Any buck-boost converter that provides the voltage and current you need should work. This is definitely what I’d recommend for teams that need a steady voltage on their robot for anything other than the radio.

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Awesome! How many can you do per PDP slot? Also, can this go into the VRM power slot?

I’m imagining that these motors are of the smaller variety. The manual lists a few motor types that can be paired on a single speed controller. If they are all running in the same direction/speed anyway, that is a way to shrink the number of PDP slots needed for the belt drive system, and simplify code just that much more as well.

R52 states that you can only have 1 Custom Circuit per PDP slot, however you may be able to do the same thing as the VRMs (1 wire into the PDP, but the wire can branch to multiple devices) but I’m not 100% sure. I believe it is legal, anyone else care to comment?

Or opposite directions (e.g. for an intake), by wiring one of the motors in reverse of the other.

The BAG motor and 9015 were added to the two-per-controller list this year.

Oh, I thought it was strictly one motor per slot! I’ll definitely check that out. Thanks!

Take a look at R30 for WHICH motors you can do that to.

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To channel the GDC, “there are no rules that prohibit that”. Basically the splice would be considered part of the custom circuit. As long as you meet the wire size requirements for the breaker size and there’s only one wire going into the PDP, it’s legal to have splices in your custom circuits.

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Unfortunately, the dual motor choices are rather subpar. Of the listed motors, I’ve only used the snow blower before, and it constantly failed on us until we switched it out for a 775. I’m asking my engineering lead what he thinks the best of those options are, do you all have any input on what we can use in place of a 775pro/redline?

(r30)

BAG motors are great. High RPM, not a lot of power, but still comparable to a 775 (and they wont burn out as easily when stalled which could be well suited to stuff like conveyors)

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See this page for motor testing info. Power curves, peak power-until-failure, and stalled rotor tests at 2V increments. Bottom line is that BAGs (and 9015s if you have them) are going to be perfectly adequate for most intake and conveyor systems this year.
https://motors.vex.com

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