Files
scanengine-3/core/rotation.py
T
Thomas Ales afe33249d1 Phase 4: extract headless ScanEngine; de-Qt the T3R driver
The headline of the refactor. Scan orchestration no longer lives inside a
QObject that reaches through Qt workers for its hardware handles.

core/scan_engine.py — ScanEngine(stage, scope, rotator, plan, out_path,
resume, callbacks). Takes the concrete drivers, blocks in run(), reports
via plain callables, and prompts through an injected blocking callable.
No Qt import anywhere in the path (test_engine_imports_without_qt proves
it), so a simpler GUI or a CLI can drive the identical acquisition.

Supporting extractions, all Qt-free:
- core/scope_sras.py  — SCPI policy: channel profiles, trigger programming,
  background average, per-row FastFrame transfer
- core/rotation.py    — RotationAxis + RotationSettings (the GR_* constants)
- core/scan_resume.py — frontier contiguity rule + settings compatibility
- gui/scan_bridge.py  — QtScanController, exposing exactly the signal
  surface the old ScanWorker had, so MainWindow's connections are unchanged

hardware/t3r_driver.py is now Qt-free: a plain Signal class, a threading
reader, and a polling thread instead of QObject/QThread/QTimer.
gui/qt_t3r.py re-emits its callbacks as queued Qt signals for the panels.

Fixes carried by the extraction:
- rotation waits on the driver's MOTION_DONE event instead of
  time.sleep(estimate + 0.5)
- abort during an operator prompt now takes effect; the old
  _prompt_event.wait() had no timeout and could not be interrupted
- the poll timer is a thread, so an I/O error tearing down the driver no
  longer calls QTimer.stop() from the wrong thread
- T3RDriver.disconnect() renamed close(); it shadowed QObject.disconnect()
- per-frame DC means use np.frombuffer over the joined block instead of
  struct.unpack per frame (~16k tuple allocations per row)

tests/fakes.py + test_scan_engine.py (14 tests) assert the exact command
sequence, file layout, resume seeking, abort/pause, and geometry
rejection before any hardware call; test_scan_resume.py covers the
frontier rule. 58 passing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-28 11:11:09 -05:00

88 lines
3.3 KiB
Python

"""GR rotation axis: the T3R configuration and move policy for scanning.
Qt-free façade over hardware.t3r_driver.T3RDriver that owns the drive
settings the scan depends on, so the engine never re-derives them.
"""
from __future__ import annotations
import logging
from dataclasses import dataclass
logger = logging.getLogger(__name__)
@dataclass(frozen=True)
class RotationSettings:
"""Drive settings for the GR axis during a scan."""
microsteps: int = 8 # microsteps/full-step on the GR axis (ch3)
velocity: int = 4000 # steps/s for inter-angle moves
accel: int = 2000 # steps/s² for inter-angle moves
run_current_ma: int = 1200 # drive current while moving
hold_current_ma: int = 400 # standstill current
ihold_delay: int = 6 # run→hold current ramp delay (TMC IHOLDDELAY units)
# The sample rotates CW instead of CCW to clear wiring and avoid a stall.
rotation_sign: int = -1
DEFAULT_ROTATION = RotationSettings()
class RotationAxis:
"""Blocking rotation control for the GR axis.
``configure()`` must run before any move: ``steps_for_angle()`` assumes
the configured microstep setting, so the device has to be told to match
rather than trusting whatever the T3R panel or firmware default left it
at.
"""
def __init__(self, driver, settings: RotationSettings = DEFAULT_ROTATION):
self.driver = driver
self.settings = settings
self._current_deg = 0.0
@property
def is_available(self) -> bool:
return self.driver is not None and self.driver.is_open
@property
def current_deg(self) -> float:
return self._current_deg
def configure(self) -> None:
s = self.settings
ch = self.driver.GR_AXIS_CH
self.driver.set_microstep(ch, s.microsteps)
self.driver.set_current(ch, s.run_current_ma, s.hold_current_ma, s.ihold_delay)
self.driver.enable(ch)
def estimate_move_secs(self, delta_deg: float) -> float:
"""Trapezoidal move time: cruise + accel/decel ramps."""
s = self.settings
steps = abs(self.driver.steps_for_angle(delta_deg, s.microsteps))
return steps / s.velocity + s.velocity / s.accel
def rotate_to(self, angle_deg: float, timeout_margin_s: float = 5.0) -> float:
"""Rotate to an absolute angle and block until the move completes.
Returns the estimated move time (for status reporting). Waits on the
driver's MOTION_DONE event rather than sleeping for a guessed
duration; falls back to the estimate only if the event never arrives.
"""
delta_deg = angle_deg - self._current_deg
if abs(delta_deg) <= 0.001:
return 0.0
s = self.settings
est_secs = self.estimate_move_secs(delta_deg)
self.driver.rotate_stage(delta_deg, s.microsteps, s.velocity, s.accel)
if not self.driver.wait_motion_done(self.driver.GR_AXIS_CH,
est_secs + timeout_margin_s):
logger.warning(
"GR axis did not report MOTION_DONE within %.1f s for a "
"%.1f° move; continuing", est_secs + timeout_margin_s, delta_deg)
self._current_deg = angle_deg
return est_secs
def return_to_zero(self) -> float:
return self.rotate_to(0.0)