Citrus Circuits

​

Basic Components�Lesson 2

Lesson Summary:

• FRC Control System Overview
• Introduction to Basic Components
• Will be taught what they do
• Will be passed around
• Future of FRC Parts???

​

FRC Control System Overview

The basics of the current control system has been roughly the same since 2015, just with updated parts

​

*Other components not on the diagram can be wired into the system as well (ex. SPARK Max, LEDs, extra PCM, custom circuit boards, sensors, cameras etc.

Fuses VS Breakers

• Fuses: ← Commonly used on small wires
• One use
• Have a metal piece inside of them with a wave pattern.
• If the amperage (flow rate of electrons) gets too high, it breaks and permanently shuts flow of electricity
• Breakers: ← Commonly used on medium wires
• Reusable
• If amperage gets too high, it temporarily halts the flow of electrons, and doesn’t have to be replaced after an overcharge.

Power Distribution Hub (PDH)

• Each motor controller needs to be connected to a slot on the board
• Provides power to the RoboRio, PCM, VRM, and all Falcons
• PDH gets power from the battery and distributes the power to all of the other components

​

• Black wire from the lead acid battery connector to negative PDP terminal
• Red wire from the main breaker to positive terminal on PDP

Voltage Regulator Module (VRM)

• Has a system which regulates the voltage so it remains constant, even if the input voltage it gets varies.
• Wired to PDP
• Used to power the radio
• Connected to radio through 12V 2A connection on VRM
• MAJOR FLAW:
• Only has two of the slots we use most.
• Because of this, we now use the MPM

Mini Power Module (MPM)

• Relatively new we only got these around March of 2023.
• Functions as a better VRM, takes in a power input from the PDH and outputs it into 6 smaller outputs
• Each of these are individually fused, meaning if one goes down, only that one goes down.
• We will have two of these per robot, replacing the VRMs.
• One of these will be for the 4 CANcoders and the Pigeon 2.0

Falcon 500

• The best motor we use, and usually the only motor we use.
• Very efficient (Brushless)
• Much lower chance of overheating than other motors
• Really good RPM and Torque.
• Incorporated in CAN loop
• Most other brushless motors aren’t in the CAN loop, they instead need speed controllers to control speed

​

The RoboRIO

• The central brain of the robot
• Receives signals from sensors, and sends out signals to motors and other components.
• We use mostly only the top row and the row to the right, alongside RSL.
• We use DIO also, but less often.
• At the top row, you see something that says “CAN”
• This is the CAN output, where it sends out the CAN loop to the rest of the robot. (Starting point)
• Next to it is something which says INPUT. This is where we get power to from the PDH.

The RoboRIO (Cont.)

• After that, we have a few slots for some software systems, mainly the port right next to the input, and the two USB ports.
• Next to there, we have the Ethernet port.
• This is where we connect to the Radio.
• On the right side, it says PWM.
• This is where we plug in all our sensors.
• We normally cover the rest of the ports with electrical tape to prevent shorts.

The Radio

• The way how the robot communicates with the Driver’s Laptop

​

• Has a wifi network which it creates, and transfers data over

​

• Two Ethernet ports, normally have one going to the Ethernet Switch, and one to the RoboRIO

Radio Power Module (RPM)

• Is how we can power the Radio without using the plug
• Is very clear which side is the input and output
• Has a power input and an input from the RoboRIO, and then “injects” the power into the Ethernet output.
• Is much safer than using the regular radio plug, which is quite prone to falling out or becoming loose, even with hot glue.

Pigeon 2.0

​

• Tells us exactly what orientation and speed the robot is going.
• The RoboRIO does have both of these already, but they are quite inaccurate and do drift off, unlike the Pigeon.
• Normally placed near the center of the robot.
• Placing it here leads to minimal issues regarding it.

​

​

CANivore

• Creates a second faster CAN loop
• We normally put every component on this CAN loop, and only use the built-in one on the RoboRIO for connecting to the PDH
• Has inputs on one side for power, and an output for CAN.
• Opposing this is a USB-C Input
• Plugs into RoboRIO, is how the CANivore gets its signal.

CANcoders

• A magnetic encoder, which uses the CAN loop.
• Magnetic encoders detect the rotation of a magnet, which is placed in a spinning component. I
• The CANcoder takes this measurement and sends it out into the CAN loop.

​

We use these to measure the rotation of the wheel, so software can get accurate autos and driving.

The Future of the FRC Control System

• In February 2020, FIRST announced that there will be a new control system from 2022 to 2026 primarily provided by National Instruments and REV Robotics.
• National Instruments will provide a next generation roboRIO
• Increased RAM and flash memory
• Improved low-voltage protection
• REV will provide new modules
• Pneumatic Hub - 12 solenoid channels
• Voltage Regulation Hub - 12V or 5V module options, 3 individually protected output channels (Hopefully will be even better than the MPM)
• A new radio is being worked on by an unidentified party/supplier.

QUIZ TIME!

​

• Q1: What is this component, and what does it’s name stand for?

a: PDH (Power Distribution Hub) c: MPM (Modular Powering Macro)

b: MPM (Mini Power Module) d: PDH (Power Dispensing Hub)

• Q2: Why did we stop using the VRM?

a: I spent all the money on other stuff :( c: Only had a small amount of good slots

b: It was too big and clunky d: It had issues where it had a risk of messing up the can loop

• Q3: What is the most important difference between fuses and�breakers?

a: Fuses are big, Breakers are small. c: Fuses are single use, Breakers are multi-use.

b: Breakers are single use, Fuses are multi-use. d: Breakers are big, Fuses are small.

• Q4: Which of the following is where the RoboRIO gets its power directed from?

a: The Battery c: The MPM

b: The Main Breaker d: The PDH

• Q5: What makes Falcon 500s so good?

a: They are brushed motors, thus last longer c: They use PWM instead of CAN.

b: They are really heavy and keep us upright d: They are brushless, more efficient

QUIZ ANSWERS!

​

• Q1: B, It is the MPM, aka the Mini Power Module

​

• Q2: C, the VRM only had a small amount of good slots.

​

• Q3: C, Fuses are single use, Breakers are multi-use.�
• Q4: D, The RoboRIO gets its power from the PDH.

​

• Q5: D, They are brushless motors, thus more efficient.