step.motion.drive_to_analog_target

Drive until an analog sensor reaches its calibrated reference value.

Loads the target raw value stored by calibrate_analog_sensor() and drives the robot forward or backward until the sensor reading crosses that threshold. Direction is determined automatically at start time by comparing the current reading to the calibrated target.

Classes

DriveToAnalogTarget

Drive until an analog sensor reaches its calibrated reference value.

Module Contents

class step.motion.drive_to_analog_target.DriveToAnalogTarget(sensor: raccoon.hal.AnalogSensor, speed: float = 0.3, set_name: str = 'default', timeout_cm: float | None = None)

Bases: step.motion.motion_step.MotionStep

Drive until an analog sensor reaches its calibrated reference value.

Reads the reference raw value stored by calibrate_analog_sensor() for the given sensor and set name, then drives forward or backward at the specified speed until sensor.read() crosses that threshold. Direction is chosen automatically: if the current reading is below the target the robot drives forward (toward the target); if it is already above the target the robot drives backward.

A timeout_cm can be provided as a safety backstop — the step stops after that distance even if the sensor has not reached the target.

Prerequisites:

calibrate_analog_sensor(sensor, set_name=...) must have been run (or a stored calibration must exist) before this step executes. Raises RuntimeError if no calibration data is found.

Parameters:

• sensor – The analog sensor used to detect the target position.

• speed – Drive speed as a fraction of maximum (0.0–1.0, default 0.3). Use a slow speed for precise positioning.

• set_name – Which stored calibration point to target (default "default").

• timeout_cm – Maximum distance to drive in centimetres before giving up. None disables the distance limit (default).

Returns:

A DriveToAnalogTarget instance.

Raises:

RuntimeError – If no calibration data exists for the given sensor and set name.

Example:

from raccoon.step.motion import drive_to_analog_target

# Drive to the default calibrated ET-sensor position
drive_to_analog_target(robot.defs.et_sensor)

# Slower approach to a named position with 30 cm safety backstop
drive_to_analog_target(
    robot.defs.et_sensor,
    speed=0.2,
    set_name="near",
    timeout_cm=30,
)

on_start(robot: raccoon.robot.api.GenericRobot) → None

Called once before the loop. Override to set up motion/velocity.

on_update(robot: raccoon.robot.api.GenericRobot, dt: float) → bool

Called each cycle with dt in seconds. Return True when motion is complete.