Example: drive, slow mode, and an intake that starts on

For: students who have driven a robot with the library and want a full TeleOp to copy. You need: lessons 2 (drive) and 3 (buttons), or the same knowledge.

A complete TeleOp for a common robot: a mecanum drive with a slow-mode toggle, and an intake that is ON from the start, can be stopped and started, and reversed while a button is held.

Program: ExampleDriveIntake.java Needs: motors front_left, front_right, back_left, back_right, intake.

The controls (gamepad 1)

Control	Does
Left stick	drive (forward/back, sideways)
Right stick X	turn
Y	slow mode on/off (2 buzzes = on, 1 buzz = off)
Right bumper	intake on/off
Left bumper (hold)	intake reverse (spit out); let go = back to what it was doing
BACK	debug telemetry on/off

How the intake logic works

Two simple switches decide what the intake does, every loop:

flowchart TB
    Q1{"left bumper held?"} -- yes --> OUT["intake.out()"]
    Q1 -- no --> Q2{"intakeOn?"}
    Q2 -- yes --> IN["intake.in()"]
    Q2 -- no --> STOP["intake.stop()"]

In the code below, () -> ... is a lambda: a small piece of code handed to a button, to run when it is pressed (or, with bindRelease, let go).

private boolean intakeOn = true;          // the intake starts ON
private boolean reversing = false;        // true while the left bumper is held
...
// The buttons only change the two switches. "!" = not, so RB flips intakeOn.
.bindPress(Pad.G1, Btn.RB, () -> intakeOn = !intakeOn)
.bindPress(Pad.G1, Btn.LB, () -> reversing = true)
.bindRelease(Pad.G1, Btn.LB, () -> reversing = false)
...
// every loop:
if (reversing) intake.out();       // reverse wins
else if (intakeOn) intake.in();
else intake.stop();
intake.update();                   // the motor gets its power here

Why switches instead of calling intake.in() from the buttons directly? Because then the rules are in ONE place you can read top to bottom. “Reverse wins” is one line. When you let go of the reverse button, the intake goes back to on OR off, whichever it was, with no extra code.

Why is it safe to call in() every loop? SpinMotor.in() does nothing if it is already running in, so it does not interrupt anything (like a jam back-out).

“Defaulted to on”: intakeOn starts true, and the first loop after START turns it on. It never runs during INIT (motors must not move before START).

How slow mode works

// bindToggle(pad, button, code when it turns ON, code when it turns OFF)
.bindToggle(Pad.G1, Btn.Y,
        () -> { slowMode = true;  confirm.play(true); },
        () -> { slowMode = false; confirm.play(false); })
...
double speed = slowMode ? SLOW_SPEED : 1.0;   // "a ? b : c" = if a then b, else c
drive.drive(forward, strafe, turn, speed);    // every wheel power times speed

A toggle is invisible, so ToggleRumble buzzes: two = on, one = off. SLOW_SPEED (0.35) is a constant at the top of the file, so it is easy to find and change.

Make it yours

• Two drivers: change the intake bindings to Pad.G2.
• Jam protection: add .jamDetection(80, 0.3, 0.4) to the intake (needs its encoder cable).
• Tune slow speed live: static final Tunable SLOW = Tunable.number("Drive/slow", 0.35, 0.05); and SLOW.get() (tuning guide).
• Trigger slow mode instead of a toggle: StickShaping.slowScale(gamepad1.left_trigger, 0.35).