With the new VH-109 radio replacing the outgoing OMP5-AC, I guess it is time to update our 2019 (2015 CTRE) and 2022 (REV) Control System Diagrams for the 2025 Season (up until the new robot controllers come out in 2027 i guess).
Basic/Primer Diagram
Understanding from feedback that the original diagrams can be confusing and too complex especially for rookie teams, with subsystems and components that you would not normally need for an FRC robot to be legal at the bare minimum, a new primer diagram, that gives a much simpler, introductory look at how the FRC Control system hardware is set up with basic components, what they do, and their importance (plus a couple of tips) now exists.
These diagrams are the direct successor of the two older diagrams they are replacing. These offer a fairly comprehensive visual look at how a control system hardware setup can be connected together for an FRC Robot using the current vendor systems.
Amazing! I cannot thank you enough for including the individual component svg files, this means we can really easily make our own wiring diagram with something like Draw.io or Visio.
In my professional life, I use stuff like this for network diagrams, and I can never find images of the actual devices I am making diagrams for, so this is sweet!
Thanks, great resources. What program do you use to create the system diagrams? I want our students to create a diagram for our bot to hang in the pit.
We use illustrator for these diagrams and the component illustrations, looking into using figma for future/new diagrams though (its nicely collaborative, not great if you want to print them though but there are workarounds).
Do not have to use either of those though, pretty much any software that can work with images and lines are able to do them (draw.io, miro, microsoft paint, sketchbook pro, procreate etc…)
robot-specific diagrams are neat, we havent done them ourselves but might be looking to do them next year too.
Omg yes! Strip lengths would be really valuable! Especially for the Rev one…
If you do that, please put a reference ruler bit in the corner for scale checking…
Will be implementing them shortly (at least the errors), will see on the strip length guide/tips (since will have to find/make space for them) but its tempting since its something that yeah i agree will be very helpful.
One small suggestion, you can simplify the plumbing for the pressure tanks by using a T-connection off the compressor. A single tube to the air tanks is fine, the air will flow in or out as needed, it doesn’t need to go “through” the tank.
Since you showed how to cut tubing you could also include how to wrap tape around the “hard” connections. Students often wrap the wrong direction, start too close to the end, and go too many times around.
Also note for other teams like mine that solenoids can operate on 24V and the pressure sensor can be digital or analog.
It would be interesting to have things like CANivore, CANcoders, and Pigeon 2.0 on the CTRE one or a separate one with stuff like that and some other products I didn’t list. Those are in my opinion the ones that need to be looked up the most on my team.
Could you add how to wire in a strip of addressable LEDs? They may draw over 1 amp, depending on the strip length, and it is not clear to me if the RoboRIO’s PWM can power them or if they need to powered by the VRM, with only the signal coming from the PWM. I have been doing the latter.
Inspired by your team my team is developing one Control System Diagram too! We’re implementing new components that we utilized during the Crescendo season, here’s a print screen of our ongoing design:
The diagram is still ongoing, if you guys have any more ideas on what would be cool to have in the diagram, please let me know!
We came up with the idea of creating our diagram because we presented our robot diagram on the pit, here is the photo:
The RoboRIO’s PWM power rail is designed to power servos, so it can source up to 2.2 amps. The problem, however, is it’s at 6V, not 5V, so if you use it, it may significantly overvolt your 5V strand. The good news is the DIO power rail is 5V and can source up to 1 amp.
A VRM has very limited capacity (1.5 A continuous) not much more than the DIO. There are 100’s of THIS type of regulator. Established teams may still have a few of them from the D-Link radio. We use this type for our LEDS (regulator $8 to $25 depending on amperage and minimum input voltage).
We’ve used the PWM 6V rail to power 5V LEDs for a few years now and haven’t had problems with overvoltage. The rail is closer to 5.8V, and a 15% overvoltage isn’t unreasonable for most things. We’ve powered strips of ~100 LEDs without problems, but I wouldn’t go much higher than that to avoid hitting the 2.2A limit. I wouldn’t do it if it were a critical part of the robot or if there was anything else connected to the 6V rail, but few teams use PWMs anymore so it’s not really an issue.
