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controller.rs — Gamepad Input

Runs a background listener for gamepad input using the gilrs library, translating button and axis events into UDP packets sent to the rover. All dispatching is gated on the current mode (drive vs. pickup) and whether the relevant manual mode is active.

Modes

The controller operates in one of two top-level modes, toggled with the Start button:

Mode

Active when

Controls

Drive

pickup_mode = false

Left stick (forward/turn), triggers (brake)

Pickup

pickup_mode = true

Both sticks (X/Y/rotate/flick), D-pad (Z), triggers (gripper)

Within each mode, the Select button toggles the relevant manual mode (drive_manual_mode or arm_manual_mode). Commands are silently suppressed when the associated manual mode is inactive.

Threads

Three concurrent threads are spawned on startup:

start_controller_listener() — Entry point. Spawns all threads and owns the shared CommandState.

Event thread — Polls gilrs at ~125 Hz (8 ms sleep) and routes each Event to the appropriate handler. Holds the shared mutex only for the duration of each state update.

Heartbeat thread — Wakes every 2 seconds and re-sends the current state (drive axes + brake, or arm + brake). Ensures the rover never silently drifts from its commanded state if packets are dropped.

Ramp threads — Spawned on demand when a ramped button (D-pad up/down, left/right trigger in pickup mode) is pressed. Ticks at ~60 Hz and increments the axis value from 0.0 toward ±1.0 over RAMP_DURATION_SECS (1.0 s). The thread exits when the direction is set back to 0.0 on button release.

Button mapping

Button

Drive mode

Pickup mode

Start

Toggle pickup mode

Toggle pickup mode

Select

Toggle drive_manual_mode

Toggle arm_manual_mode

Left trigger (LB)

Toggle latching brake

Ramp gripper speed → close (−1.0)

Right trigger (RB)

—

Ramp gripper speed → open (+1.0)

Left trigger 2 (LT)

Toggle latching brake

—

Right trigger 2 (RT)

Momentary brake (hold)

—

D-pad up

—

Ramp Z → up (+1.0)

D-pad down

—

Ramp Z → down (−1.0)

Axis mapping

Axis

Drive mode

Pickup mode

Left stick Y

Forward / backward

Flick

Left stick X

Turn

Rotate

Right stick X

—

End effector X (left/right)

Right stick Y

—

End effector Y (forward/backward)

All analog axes pass through a deadzone (±0.05) and are only dispatched when the change from the last-sent value exceeds AXIS_CHANGE_THRESHOLD (0.05). Z and gripper speed are not axis-driven — they are ramped from button presses.

Packets sent

Packet

When

BasestationManualDrive

Drive mode, on axis change or heartbeat

BasestationManualBrake

Drive mode, on brake toggle/press/release or heartbeat; also sent continuously (engaged) during pickup heartbeat

BasestationManualArmMovement

Pickup mode, on any arm state change or heartbeat

All values are scaled from [−1.0, 1.0] to the full sint32 range before transmission.

Constants

Constant

Value

Purpose

AXIS_CHANGE_THRESHOLD

0.05

Deadzone boundary and minimum delta before a packet is sent

HEARTBEAT_INTERVAL

2 s

How often state is re-sent without an input event

RAMP_DURATION_SECS

1.0 s

Time for a ramped axis to travel from 0.0 to ±1.0

RAMP_TICK_MS

16 ms

Ramp thread tick interval (~60 Hz)

MOMENTARY_BRAKE_DURATION

500 ms

Defined but unused — auto-release was commented out

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