Logging

A logger is already setup for your use. It logs to the wpilog file on the roboRIO, as well as to NetworkTables. Tools such as AdvantageScope can read these logged values.

Most basic types implement the Loggable trait (booleans, floats, integers, &str, String, and arrays of all those values). You can log them in a system using the Logger resource like so:

#![allow(unused)]
fn main() {
fn log(mut logger: ResourceMut<Logger>) {
    logger.append_value("Path/Number", 5.0);
}
}

The append_value function is only for basic values that implement Loggable. If you want to log types that have multiple values, you should use the append function (which supports all Loggable types as well).

AutoLog

Similar to AdvantageKit, there is an AutoLog trait which you can automatically implement for any struct that is made up of types that themselves implement AutoLog.

For example, the state for an intake subsystem could be specified like so:

#![allow(unused)]
fn main() {
#[derive(AutoLog)]
struct IntakeState {
    speed: AngularVelocity,
    angle: Angle,
}
}

You could then log this by calling logger.append("Intake", intake_state). Note that unit types also can all be logged.

You can also nest loggable types:

#![allow(unused)]
fn main() {
#[derive(AutoLog)]
struct IntakePivotState {
    angle: Angle,
    velocity: AngularVelocity,
}

#[derive(AutoLog)]
struct IntakeState {
    velocity: AngularVelocity,
    pivot: IntakePivotState,
}
}

The logging tree for the new IntakeState would look like this:

• Intake/velocity
• Intake/pivot/angle
• Intake/pivot/velocity