the video version
The same lesson as a narrated video. Watch it on YouTube
Every FRC robot shares a common control system#
To keep the competition safe and fair, FIRST requires every robot to use a standardized control system. Knowing these components by name makes the whole sport legible — you'll understand pit conversations, match-day failures, and the Game Manual's robot rules.
The core hardware#
The brain: roboRIO#
The NI roboRIO is the main robot controller — the 'brain' that runs your team's code and commands everything else. It connects to motor controllers, sensors, and the radio. (Looking ahead: FIRST is replacing the roboRIO with a new controller called SystemCore starting in the 2027 season, but the roboRIO is the required brain through 2026.)
Power: battery and distribution#
- A single 12V, 18Ah Sealed Lead-Acid (SLA) battery powers the whole robot.
- A 120A Main Circuit Breaker acts as both the master power switch and overcurrent protection.
- A REV Power Distribution Hub (PDH) — with 20 high-current (40A-max) channels — or a CTR Electronics Power Distribution Panel (PDP / PDP 2.0) distributes power through auto-resetting circuit breakers and fuses, protecting each branch of the robot.
- Clean power wiring is essential to avoid 'brownouts' (the robot losing power and resetting under heavy load).
Making things move: motors and motor controllers#
Motors don't connect directly to the roboRIO — a motor controller sits in between and translates commands into power:
- CTR Electronics Talon FX, integrated into the Falcon 500, Kraken X60, and Kraken X44 brushless motors (with built-in encoders and smart features), plus the standalone Talon FXS.
- REV Robotics SPARK MAX and SPARK Flex, which drive brushed motors or the brushless NEO and NEO Vortex motors.
- These communicate over the CAN bus (a robust daisy-chained data network) or PWM.
Communication: the radio#
The robot's radio provides the wireless link to the Field Management System (FMS) at events and to the Driver Station laptop in the pit. The current standard radio is the Vivid-Hosting VH-109, which uses Wi-Fi 6E to avoid the 2.4 GHz congestion that plagued the previous-generation OpenMesh radios (OM5P-AN and OM5P-AC). Those radios are no longer used in most of the world, but the 2026 manual (R702) still requires an OpenMesh radio at events held in China.
Sensing and pneumatics (optional but common)#
Teams add sensors (encoders, gyros, limit switches, cameras) and may use pneumatics via a REV Pneumatic Hub or CTRE Pneumatics Control Module for air-powered mechanisms.
The core software#
WPILib#
WPILib is the official, free software library and toolchain for programming FRC robots. It installs a customized version of Visual Studio Code and supports three languages:
- Java (most popular in FRC)
- C++
- Python (via RobotPy)
WPILib provides the building blocks for drivetrains, sensors, command-based robot structure, and simulation. (LabVIEW was supported for many years but has been deprecated and is not supported on the upcoming SystemCore controller — new teams should choose Java, C++, or Python.)
FRC Driver Station#
The FRC Driver Station (Windows-only) is the program that enables/disables the robot, selects autonomous vs. teleop, and routes joystick/gamepad input. At an event it talks to the FMS; in the pit it connects to the radio directly.
Vendor tools and vision#
- REV Hardware Client and Phoenix Tuner X (CTR) configure and update firmware on motor controllers and devices.
- Limelight and PhotonVision provide camera-based targeting (e.g., aligning to AprilTags, scoring locations, or game pieces).
How it all fits together#
A simplified signal path: your WPILib code runs on the roboRIO, which sends commands over CAN to motor controllers, which drive motors, powered through the PDH/PDP from the 12V battery — while the Driver Station (via the radio and FMS) tells the robot when it's enabled and feeds it driver input.
The official WPILib Zero-to-Robot guide walks a rookie through wiring and programming this exact system, which we cover in the next module.
Learn more#
- FRC Control System Hardware overview: https://docs.wpilib.org/en/stable/docs/controls-overviews/control-system-hardware.html
- WPILib documentation home: https://docs.wpilib.org
the part worth keeping
Key takeaways
- Every FRC robot uses a standardized control system: a roboRIO brain, a 12V 18Ah SLA battery behind a 120A main breaker feeding a REV PDH or CTR PDP, motor controllers (Talon FX/Kraken, SPARK MAX/NEO), the Vivid-Hosting VH-109 radio, and sensors.
- Motors are driven through motor controllers (not directly), usually over the CAN bus, and clean power wiring prevents brownouts.
- Software is built on free WPILib (Java, C++, or Python in VS Code) plus the Windows FRC Driver Station, with vendor tools and Limelight/PhotonVision for configuration and vision; LabVIEW is deprecated and roboRIO gives way to SystemCore in 2027.
Getting Started with FRCCulture, Teams, and Roleslesson 3 of 3
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where this came from
Sources and corrections
This lesson is AI-assisted: drafted from primary sources, then reviewed and edited by hand. Errors still get through. When one is reported we fix it and write down what changed, in public, in the corrections log.
last correctedsee what changed
sources and further reading
- docs.wpilib.orgFRC Control System Hardware Overview (WPILib)
- docs.wpilib.orgWPILib Documentation
clipped to this lesson
Articles that go further on this
The lesson gets you through the topic. These go wider on it, and they read in one sitting.
- 8 min readThe FRC Control System Explained: roboRIO, PDH, Radio, and Everything BetweenThe FRC control system explained: how the roboRIO, REV PDH, radio, motor controllers, and CAN bus connect to make your robot drive — a plain-English electronics board tour./blogread it
- 20 min readREV Robotics for FRC: NEO Motors, Spark MAX/Flex, PDH & MAXSwerveA practical guide to the REV Robotics FRC ecosystem: NEO, NEO Vortex and NEO 550 motors, Spark MAX and Spark Flex controllers, the PDH, and MAXSwerve./blogread it
- 19 min readFRC PDH: The Power Distribution Hub Explained (Channels, Fuses & Wiring)A complete guide to the REV PDH (Power Distribution Hub): all 24 channels, breaker and fuse sizing, clean wiring, the switchable channel, CAN telemetry, and PDH vs PDP./blogread it
answer sheet
Lesson quiz
All 3 right completes the lesson. Miss one and only that question comes back, anything you already answered correctly stays banked.
0 of 3 answered
01In the standard FRC control system, which device serves as the robot's main controller, or 'brain,' running the team's code to command the rest of the hardware?
02What is the nominal voltage of the single sealed lead-acid battery that powers a standard FRC robot?
03Which communication bus is commonly used so devices like the Power Distribution module and smart motor controllers can talk to the roboRIO over a shared wiring loop?
Answer every question to submit.
All 28 lessons in Getting Started with FRCopenclose
01 / what-first-and-frc-are
02 / the-season-and-the-game
03 / culture-teams-and-roles
04 / getting-started-your-first-steps
05 / worked-examples-mini-projects
- Not read yet:Project 1 — Make a NEO Spin with the REV Hardware Client
- Not read yet:Project 2 — Deploy a Real Arcade-Drive Program
- Not read yet:Project 3 — Refactor into a Command-Based Drive Subsystem
- Not read yet:Project 4 — Build a Fuel Launcher for REBUILT
- Not read yet:Project 5 — A One-Button Autonomous Routine
06 / common-mistakes-troubleshooting
- Not read yet:The Connection Chain: When the Driver Station Won't Connect
- Not read yet:Brownouts: Why the Robot Goes Limp Mid-Match
- Not read yet:CAN Bus Gremlins: Missing and Conflicting Devices
- Not read yet:Software Gotchas: Inverted Drives, Scheduler Stalls, and Reading the RioLog
- Not read yet:Inspection-Day Failures: Bumpers, Size, and Weight
07 / advanced-techniques-case-studies
- Not read yet:Closed-Loop Control: PID + Feedforward for a Consistent Shot
- Not read yet:Swerve Drive: Omnidirectional Movement with YAGSL
- Not read yet:AprilTag Vision: Knowing Where You Are with PhotonVision
- Not read yet:Data-Driven Strategy: Scouting, EPA/OPR, and Alliance Selection
- Not read yet:Choosing Your Hardware Ecosystem: REV vs CTRE