The FrogPilot and openpilot communities use a lot of shorthand and technical language. This page is a quick reference to help you decode what everything means.
Driver Assistance & Safety
| Acronym | Full Name |
|---|---|
| ACC | Adaptive Cruise Control (cruise control that automatically adjusts your speed to maintain a safe following distance from the car ahead, speeding up and slowing down as needed) |
| ADAS | Advanced Driver Assistance Systems (the umbrella term for all the safety and driver assistance features built into modern cars, including adaptive cruise control, lane keeping, automatic emergency braking, blind spot monitoring, and more) |
| AEB | Automatic Emergency Braking (a safety system that automatically applies the brakes when a collision is imminent and the driver hasn't reacted in time) |
| ALC | Automatic Lane Centering/Change |
| BSM | Blind Spot Monitoring (sensors that warn you when a vehicle is in your blind spot, usually indicated by a light on the side mirror) |
| Co-Pilot360 | Ford and Lincoln's suite of driver assistance features, including pre-collision assist, blind spot monitoring, and lane keeping; openpilot requires the Co-Pilot360 Assist+ package or higher, which adds adaptive cruise control with stop-and-go and active lane centering |
| DM | Driver Monitoring (the cabin-facing camera system that watches your face to make sure you're paying attention to the road) |
| DMS | Driver Monitoring System (the full hardware and software package for tracking driver attention, including the cabin-facing camera, face detection, and the alerts it triggers when you look away too long) |
| DRCC | Dynamic Radar Cruise Control (Toyota's name for their adaptive cruise control system) |
| EyeSight | Subaru's stereo-camera driver assistance system providing adaptive cruise, lane centering, pre-collision braking, and lane departure warning; required for openpilot compatibility on Subaru vehicles, and enabling openpilot longitudinal control will disable EyeSight's built-in safety features including automatic emergency braking |
| FCW | Forward Collision Warning (an alert that warns you when you're closing in on the car ahead too quickly; unlike AEB, it only warns and doesn't brake for you) |
| HDA | Highway Drive Assist (Hyundai's system combining lane centering and adaptive cruise control for highway driving; the standard ADAS package on most supported Hyundai, Kia, and Genesis vehicles) |
| HDA II | Highway Driving Assist II (the advanced version of HDA on newer CAN-FD vehicles like the Ioniq 5, Ioniq 6, and EV6; adds navigation-based driving assistance and uses a different internal architecture where the ADAS computer sits on the car's main bus instead of the camera bus, which changes the harness wiring needed) |
| Honda SENSING | Honda and Acura's driver assistance suite, including collision mitigation braking, road departure mitigation, adaptive cruise with low-speed follow, and lane keeping assist; openpilot replaces the lane keeping and, on many models, can also take over gas and braking |
| LDW | Lane Departure Warning (an alert that warns you when you drift out of your lane without a turn signal on; it only warns and doesn't steer for you, unlike LKAS or LTA) |
| LFA | Lane Follow Assist (Hyundai, Kia, and Genesis lane centering system that actively steers to keep you centered in your lane) |
| LKAS | Lane Keeping Assist System (a system that actively steers to help keep the car in its lane; this is the system openpilot replaces on Honda and Acura vehicles) |
| LTA | Lane Trace Assist (Toyota's active lane centering system that steers to keep you centered in your lane; this is what openpilot controls for steering on TSS2 and newer Toyotas) |
| ProPILOT Assist | Nissan's driver assistance system combining adaptive cruise control and steering assist for highway driving; available on models like the Leaf, Rogue, and Altima, and required for openpilot compatibility on Nissan vehicles |
| RCTA | Rear Cross Traffic Alert (a warning system that detects vehicles crossing behind you when you're backing out of a parking space) |
| RDM | Road Departure Mitigation (Honda's safety system that actively steers you back into your lane if you drift toward the road edge) |
| RSA | Road Sign Assist (Toyota's camera-based system for reading speed limit signs and displaying them on the dashboard) |
| SCC | Smart Cruise Control (Hyundai, Kia, and Genesis adaptive cruise control system that maintains distance from the car ahead and can bring you to a full stop in traffic) |
| SNG | Stop and Go (the ability to automatically stop in traffic and resume when the car ahead moves; see the full definition in Driving & Controls below) |
| Super Cruise | GM's hands-free highway driving system that uses pre-mapped roads and a driver attention camera to allow hands-off driving on certain highways; the Chevrolet Bolt with standard adaptive cruise control is supported by openpilot, but the Super Cruise trim has a different architecture that isn't compatible |
| TSS | Toyota Safety Sense (Toyota's umbrella name for their driver assistance features; comes in several generations with different capabilities and levels of openpilot support) |
| TSS-P | Toyota Safety Sense P (the first generation, with pre-collision warning, automatic emergency braking, lane departure alert, and radar cruise control; openpilot can steer on TSS-P cars, but gas and braking typically stay with the car's built-in cruise control unless a comma pedal or DSU is used) |
| TSS2 | Toyota Safety Sense 2.0 (the second generation, adding Lane Tracing Assist for active lane centering, full-speed radar cruise control, and Road Sign Assist; most TSS2 cars have full openpilot support for both steering and speed control) |
| TSS2.5 | Toyota Safety Sense 2.5 (an incremental update to TSS2 found on some 2021+ models like the Camry, Avalon, and Mirai, with higher steering torque limits and SecOC encryption on the CAN bus; fully supported by openpilot) |
| TSS3 | Toyota Safety Sense 3.0 (the latest generation on 2022+ Toyotas, adding intersection collision prevention, night pedestrian and cyclist detection, Emergency Steering Assist, and Proactive Driving Assist; openpilot support depends on whether the specific vehicle uses the Toyota Security Key encryption) |
Driving & Controls
| Technical Term | What It Means |
|---|---|
| Acceleration Path | An on-screen overlay that shows openpilot's current acceleration or braking intensity as a visual gradient on the driving path |
| Acceleration profile | How quickly openpilot speeds up, with options from gentle (Eco) to moderate (Sport) to maximum (Sport+) |
| Adjacent Lanes | An on-screen display that draws the lanes next to yours, showing what the driving model detects on either side |
| Blind Spot Path | A red overlay on the driving screen that appears in an adjacent lane when your car's blind spot monitor detects a vehicle there |
| Border colors | The colored border around the driving screen that shows the current state: green means engaged, blue means Always On Lateral, gray means disengaged, and orange means a driver attention warning |
| Calibration | The process where the device determines the camera's exact mounting angle relative to the road using the driving model's visual motion estimates while you drive above 15 mph in a straight line; takes a few minutes of driving to complete, and you'll see a progress percentage on screen until it finishes. If the device is moved or remounted, it will need to recalibrate |
| Chill Mode | The standard, non-experimental driving mode where openpilot follows lanes and adjusts speed using conventional rules rather than end-to-end predictions (the opposite of Experimental Mode) |
| Dashcam Mode | A passive mode where openpilot records video but doesn't control the car at all; used on unsupported or partially supported vehicles where openpilot can't safely steer or control speed |
| Deceleration profile | How firmly openpilot slows down, from gentle coasting (Eco) to stronger braking (Sport) |
| Desire | The driving model's internal way of expressing intent to change lanes; you might see this term in logs or developer discussions when the model is planning a lane change |
| Disengage / Disengagement | When openpilot stops controlling the car, either because you pressed cancel, turned the wheel firmly, or the system detected a problem; after disengagement, you're fully in control |
| Driving personality | A switchable driving style that controls how aggressively openpilot follows, accelerates, and brakes; the four options are Traffic, Aggressive, Standard, and Relaxed |
| Driving policy | The part of the driving model that decides when to brake, accelerate, or steer based on what the camera sees |
| Ego / Ego vehicle | Your own car; you'll see this term in logs and developer discussions to distinguish your car from other vehicles on the road |
| End-to-end | A driving approach where a single neural network goes directly from raw camera images to steering and speed decisions in one step, rather than using separate systems for detecting lanes, identifying objects, and planning a path |
| Engage / Engagement | When openpilot starts actively controlling the car's steering and/or speed; you engage by pressing the cruise control stalk or set button on your steering wheel |
| Following distance | The time gap openpilot keeps between your car and the vehicle ahead, measured in seconds; adjustable with the distance button on your steering wheel or through driving personality settings |
| Force stop | A FrogPilot feature that brings the car to a complete stop when the driving model detects a stop light or stop sign ahead |
| Green Light Alert | A FrogPilot notification that tells you when a traffic light ahead has turned green while you're stopped |
| Jerk (physics) | How quickly acceleration changes; lower jerk means smoother speed changes, higher jerk means more abrupt transitions |
| Lateral / Lateral control | Steering; when you see "lateral" in settings or discussions, it means anything related to steering the car left and right |
| Lead (noun) | The car directly ahead of you that openpilot is tracking; openpilot adjusts its speed and following distance based on the lead vehicle's position and speed |
| Lead Departing Alert | A FrogPilot notification that tells you the car ahead has started moving while you're still stopped |
| Longitudinal / Longitudinal control | Gas and braking; when you see "longitudinal" in settings or discussions, it means anything related to speeding up and slowing down |
| Neural network | The AI driving model that processes camera images to decide where to steer and when to brake; openpilot's main neural network is called "supercombo" and handles both seeing the road and planning what to do |
| Onroad / Offroad | The device's two states: onroad means the car is running and openpilot can drive, offroad means the car is parked with the settings screen showing |
| openpilot longitudinal | When openpilot directly controls gas and braking using its own driving model and camera, rather than relying on the car's built-in cruise control; provides smoother following, better stop-and-go behavior, and more tuning options, but isn't available on every car (compare: Stock longitudinal) |
| Override | When you take over from openpilot by pressing the gas pedal, brake pedal, or turning the steering wheel firmly enough; depending on your settings, overriding may pause openpilot temporarily or disengage it completely |
| Path | The colored lane overlay on the driving screen that shows where openpilot plans to steer; the width, color, and edges all convey information about the current driving state |
| Path colors | The color of the path overlay indicates the current mode: green (default), orange (Experimental Mode), yellow (Conditional Experimental Mode overridden), red (Traffic Mode), blue (navigation active), light blue (Always On Lateral) |
| Radar-based ACC | The car's built-in Adaptive Cruise Control, which uses its own radar sensor to track the car ahead instead of openpilot's camera-based driving model |
| Set speed | The target speed you set with the cruise control buttons on your steering wheel; openpilot won't exceed this speed unless you press the gas pedal |
| Steer ratio | The relationship between how much you turn the steering wheel and how much the front wheels turn; higher values mean more wheel rotation for the same turn, and openpilot needs to know this value to steer accurately |
| Stock longitudinal | When the car's own factory cruise control handles gas and braking while openpilot only handles steering; this is the default on cars where openpilot doesn't have direct control over acceleration and braking (compare: openpilot longitudinal) |
| Stop and Go | The ability to come to a complete stop behind a lead vehicle in traffic and automatically resume when the car ahead moves; requires openpilot longitudinal control, which isn't available on every car |
| Stopped Timer | A timer on the driving screen that shows how long you've been stopped behind a lead vehicle or at a traffic light |
| Torque (steering) | The rotational force applied to the steering wheel by openpilot; the car limits how much torque openpilot can apply, which is why it may struggle with very tight turns or sharp curves |
| Traffic Mode | A driving personality focused on stop-and-go traffic that follows the car ahead more closely and brakes later to keep up with the flow |
| Trajectory | The planned driving path that openpilot intends to follow, including both the steering line and the speed plan |
| Weather Condition Offsets | Settings that automatically adjust following distance, acceleration, and curve speed when rain, snow, or low visibility is detected through an OpenWeatherMap connection |
FrogPilot & openpilot
| Acronym | Full Name |
|---|---|
| AOL | Always On Lateral (keeps openpilot's steering active even when cruise control is off, so the car still centers in the lane while you control gas and braking yourself) |
| CEM | Conditional Experimental Mode (automatically switches between standard and Experimental Mode based on driving conditions like speed, detected stop lights, curves, or navigation turns) |
| CSC | Curve Speed Controller (automatically slows the car for upcoming curves using camera detection and/or map data to determine how sharp the curve is) |
| FP | FrogPilot |
| MTSC | Map Turn Speed Controller (a component of CSC that slows for curves based on the road's shape in the downloaded map data) |
| NNFF | Neural Network Feedforward (a community-developed steering controller by Twilsonco that uses a trained neural network to predict how much steering torque is needed for upcoming curves, resulting in smoother and more accurate steering) |
| NOO | Navigate on openpilot (turn-by-turn navigation that guides openpilot along a planned route, including taking highway exits and interchanges) |
| OP | openpilot |
| QOL | Quality of Life (convenience features and small improvements that make daily use more pleasant) |
| SLC | Speed Limit Controller (automatically adjusts your set speed to match posted speed limits using data from maps, navigation, or the car's dashboard camera) |
| VOACC | Vision Only Adaptive Cruise Control (a driving model capability where gas and braking are controlled by the camera alone, without using the car's radar sensor) |
| VTSC | Vision Turn Speed Controller (a component of CSC that slows for curves based on what the driving model's camera sees ahead on the road) |
General
| Acronym | Full Name |
|---|---|
| CAN | Controller Area Network (the wiring network connecting all the computers inside your car; every message between the engine, brakes, steering, and other systems travels over this network) |
| CAN-FD | Controller Area Network with Flexible Data-rate (a faster, higher-capacity version of CAN found in newer vehicles that can carry more data per message) |
| DBC | CAN Database (a file format that maps the raw numbers on a car's CAN bus to human-readable names like "steering angle" or "brake pressure") |
| E2E | End to End (a driving approach where a single neural network goes directly from raw camera images to driving actions, rather than using separate systems for lane detection, object recognition, and path planning) |
| ECU | Electronic Control Unit (one of the many small computers inside your car that each control a specific system like the engine, brakes, steering, or airbags) |
| EPS | Electric Power Steering (the electric motor that assists your steering; this is what openpilot sends commands to when it steers the car) |
| HKG | Hyundai/Kia/Genesis (shorthand for all three brands, which share vehicle platforms and are supported as a single group in openpilot) |
| OBD-II | On-Board Diagnostics (the standardized diagnostic port under your dashboard, originally designed for emissions testing but also used for connecting aftermarket devices) |
| OSM | Open Street Maps (a free, community-built mapping database that FrogPilot can use for speed limit and road data) |
| OTA | Over-the-Air (software updates delivered wirelessly to the device without needing to plug anything in) |
| SecOC | Secure Onboard Communication (an encryption protocol that some Toyota, Lexus, and Subaru vehicles use to verify that messages on the CAN bus are legitimate and not from an unauthorized device; openpilot supports SecOC on many vehicles, but the newer Toyota Security Key variant on some TSS3 cars hasn't been cracked yet) |
| SSH | Secure Shell (a way to remotely access your device's command line over the network for troubleshooting and development; available with comma prime) |
| TSK | Toyota Security Key (an enhanced encryption system on certain newer Toyota and Lexus vehicles that prevents third-party devices from sending commands to the car; this is the main barrier to openpilot support on affected models, and comma.ai is actively working on cracking it) |
| UI | User Interface |
| UX | User Experience |
Hardware & Devices
| Technical Term | What It Means |
|---|---|
| Clone | A non-comma hardware device built from off-the-shelf components that runs openpilot; not officially supported by comma.ai |
| comma 3X | comma.ai's previous flagship device (often shortened to C3X), with three cameras (road-facing, driver-facing, and wide-angle), built-in CAN-FD support, and an integrated panda for car communication; superseded by the comma four |
| comma four | comma.ai's newest and smallest device (often shortened to C4), about one-fifth the size of the 3X with the same processing power and three-camera setup; designed to fit discreetly behind the rearview mirror |
| comma pedal | A community-designed aftermarket device that plugs into the gas pedal wiring to give openpilot throttle control on older cars that don't natively support it; no longer manufactured but still used on some existing setups |
| comma three | An earlier comma.ai device (often shortened to C3), the first built with three cameras; still functional but superseded by the 3X and comma four |
| comma two | The second-generation comma.ai device (often shortened to C2), now discontinued; had a single road-facing camera and required an external panda for car communication |
| Distance button | A steering wheel button originally for adjusting your car's following distance that FrogPilot can remap to trigger other functions like toggling Experimental Mode or changing driving personalities |
| DSU | Driver Support Unit, a module in some older Toyotas that handles radar cruise control processing; removing or bypassing it with an SDSU allows openpilot to take over gas and braking directly on cars that otherwise wouldn't support it |
| EON | comma.ai's original device, based on a OnePlus 3T smartphone in a custom 3D-printed case with a fan for cooling; the first consumer device to run openpilot. Discontinued and no longer supported by current versions of openpilot |
| FrEON | A community-modified version of the EON that replaced the OnePlus 3T with alternative smartphone hardware while keeping the same form factor and case design |
| Harness | The cable and relay assembly that connects the comma device to your car's ADAS camera port behind the rearview mirror; each supported car model uses a specific harness connector type |
| Harness box | The small relay box built into the harness that switches control between the car's stock ADAS system and openpilot; if openpilot crashes or the device disconnects, the harness box automatically hands control back to the car's stock system as a safety measure |
| LKAS button | A steering wheel button originally for toggling lane keeping assist that FrogPilot can remap to trigger other functions |
| Mount | The bracket that attaches the comma device to your windshield, positioned behind the rearview mirror to share the same view as the car's stock ADAS camera |
| OBD-C cable | The cable connecting the comma device to the car's harness, providing both power to the device and the data connection to the car's CAN bus |
| Panda | The communication chip inside the comma device (or external on older setups) that translates between openpilot's software and the car's CAN bus; also enforces safety limits on steering torque and braking force to prevent dangerous commands from ever reaching the car |
| SDSU | Smart Driver Support Unit, a community-built replacement for the Toyota DSU that intercepts the radar cruise control signals and lets openpilot take over gas and braking on older Toyotas that don't natively support openpilot longitudinal control |
| ZSS | Zorrobyte Steering Sensor, a community-built aftermarket steering angle sensor for older Toyotas that lack a precise one from the factory; improves openpilot's steering accuracy on those vehicles |
Software & Community
| Technical Term | What It Means |
|---|---|
| AGNOS | The Ubuntu-based operating system that runs on comma three, comma 3X, and comma four devices; handles the device's hardware, networking, and camera drivers, and provides the environment where openpilot runs |
| Branch | An installation channel for FrogPilot; the main branch is stable, while Staging and Testing offer early access to upcoming features that may still have bugs |
| Cabana | comma.ai's tool for viewing and decoding CAN bus signals from your car; used by developers to reverse engineer vehicle communication when adding support for new car models |
| Cereal | openpilot's internal messaging system that processes use to talk to each other; you might see it in error logs but don't need to interact with it directly |
| comma connect | comma.ai's web dashboard (connect.comma.ai) for viewing your recorded drives on a map, managing your device remotely, setting navigation destinations, and tracking your driving statistics |
| comma prime | comma.ai's optional paid subscription that adds remote SSH access to your device, cloud storage for drive recordings, live GPS tracking, and a built-in cellular data plan so the device stays connected without Wi-Fi |
| comma prime lite | A lower-cost comma.ai subscription with the same cloud features as Prime (remote access, drive storage, GPS tracking) but without the included cellular data plan, so you need to provide your own connection via Wi-Fi or a mobile hotspot |
| Drive Summary | The post-drive screen that shows trip stats like distance, time, openpilot engagement percentage, and a prompt to rate how the driving model performed |
| Fingerprint | How openpilot identifies your specific car model on each startup by reading the unique pattern of messages on your car's CAN bus; if fingerprinting fails, you'll see an "unsupported vehicle" message |
| Fork | A modified version of openpilot maintained by an independent developer or team; forks like FrogPilot, SunnyPilot, and DragonPilot add features, customizations, and car-specific tweaks beyond what stock openpilot offers |
| Holiday Themes | Seasonal UI themes that automatically activate on holidays like Christmas, Halloween, and World Frog Day, changing the on-screen visuals and sounds |
| Konik | An alternative cloud server (connect.konik.ai) that FrogPilot can use instead of comma connect for drive uploads and statistics |
| Mapbox | The mapping service FrogPilot uses for on-device navigation and speed limit data; requires free API keys from Mapbox's website to activate |
| Model Randomizer | A feature that rotates between your downloaded driving models, letting you compare how different models handle your daily routes |
| opendbc | The open-source repository of CAN bus signal definitions (DBC files) for all vehicles supported by openpilot; this is how openpilot knows what each message on your car's network means |
| OpenWeatherMap | A weather API service that FrogPilot can connect to for detecting current weather conditions and automatically adjusting driving behavior through Weather Condition Offsets |
| Params / Params_memory | Where FrogPilot saves your settings (params, persists across reboots) and stores live driving data that resets each trip (params_memory) |
| Pre-built | A pre-compiled version of a fork that's ready to install directly on the device without needing to build the software from source code; this is how most users install FrogPilot and other forks |
| Random Events | Fun surprise alerts and animations that pop up while driving, including movie references and sound effects; toggled on in Theme and Appearance |
| Route | A recorded driving session captured by the device, including video from all cameras, CAN bus data, and GPS coordinates; viewable in comma connect or developer tools like Cabana |
| Screen Recorder | A feature in System Settings that records your driving screen as video, useful for sharing clips or reviewing drives |
| Segment | A one-minute chunk of a route; drives are split into segments to keep file sizes manageable and make uploading and reviewing easier |
| Selfdrive | The core openpilot process that coordinates perception, planning, and vehicle control in real time; if you see it in error logs, it means the main driving software encountered an issue |
| Standby Mode | A power-saving mode that turns off the device's screen while keeping it running in the background, reducing heat and power draw while parked |
| Supercombo | The name of openpilot's main driving model: a single neural network that handles both perception (detecting the road, cars, lane lines, and traffic lights) and planning (deciding where to steer and when to brake) in one combined model |
| The Pond | FrogPilot's community theme repository where you can browse and download custom color schemes, icons, sounds, and steering wheel images created by other users |
| Thneed | The compiled file format openpilot uses to run its driving models efficiently on the device's hardware; you might see .thneed files when managing driving models |
| Tinygrad | The lightweight machine learning framework openpilot uses to compile and run its neural network driving models on the device; developed by comma.ai's founder George Hotz |
| Toggle | A setting in FrogPilot you can switch on or off; the number of visible toggles depends on your tuning level, with higher levels revealing more advanced options |
| Tuning level | Controls which FrogPilot settings are visible in the menus; Minimal shows just the basics, Standard is recommended for most users, Advanced gives detailed control over driving behavior, and Developer exposes everything including debug tools |
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