Gather your robot information

YAGSL is configured entirely from information about your robot — there is no universal constants file that works for everyone. Before opening config.yagsl.com, collect everything in this step. Having it all on hand up front saves you from re-measuring later.

Every swerve drive is different, even between robots using the same COTS modules (SDS MK4, MAXSwerve, etc.). Don't assume your numbers match another team's example.

Hardware types and connections

Feature	Notes
Gyroscope model and connection	e.g. Pigeon 2.0 on CAN, NavX over USB/SPI/I2C, CANandGyro on CAN. The connection method matters — a NavX over USB is a different config than one on the MXP (SPI).
Drive motor + controller for each module	e.g. Kraken X60 on TalonFX, NEO on SparkMAX, etc.
Angle/steering motor + controller for each module	Same as above, per module.
Absolute encoder model and connection for each module	e.g. CANcoder on CAN, REV Through Bore on a data port, attached to a SparkMAX analog/duty-cycle port.
CAN bus name	rio on a roboRIO, unless you're running CTRE devices on a CANivore (use the CANivore's configured name). Starting with the 2027 SystemCore, name whichever of its several native CAN buses each device is actually on.
CAN ID / channel of every motor controller, encoder, and gyro	Get this wrong and you'll be controlling the wrong device without realizing it.

Physical characteristics

Feature	Relevance
Drive gear ratio	How many drive motor rotations produce one wheel rotation. Usually published by the module manufacturer.
Steering/angle gear ratio	How many steering motor rotations produce one full module rotation. Also published by the manufacturer.
Wheel diameter	Needed to convert motor rotations into distance traveled.
Module locations	Distance in inches from the robot's center to each module's center, split into "front" (X) and "left" (Y) components. See below for how to measure this.

Measuring module locations

Measure in CAD if you can, for precision — otherwise, use this technique from Team 5010:

1. Lay the robot on its side and rotate the wheels perpendicular to the direction you're measuring.

2. Measure to the outside of each wheel and subtract one wheel width to get the center-to-center measurement.

3. Repeat in the other direction.

Record all four module locations (front-left, front-right, back-left, back-right) relative to the robot's center, in inches:

Module	X "Front" (in)	Y "Left" (in)
Front Left (FL)	+	+
Front Right (FR)	+	−
Back Left (BL)	−	+
Back Right (BR)	−	−

Inversion and offsets — record placeholders now, fill in later

You won't be able to determine these until your code is deployed (that happens in step 4), but it helps to have a table ready:

Module	Drive Inverted?	Angle Inverted?	Absolute Encoder Inverted?	Absolute Encoder Offset (°)
Front Left (FL)
Front Right (FR)
Back Left (BL)
Back Right (BR)

Also note whether your gyroscope needs to be inverted — it must report an increasing yaw while the robot rotates counterclockwise.

A printable version of a bring-up checklist covering all of the above (courtesy of DevilBotz 2876) is available in the repository's asset folder if your team prefers a paper checklist during bring-up.

With this information in hand, move on to installing YAGSL.