Implement switches

[CatYang3]

Summary

Describe the main changes in this PR:

• Added exosuit states. Main thread monitors switches to change exosuit status accordingly.
• Added a 3-way switch for inclination modes (the configuration of which can be changed in Definitions.)
• Added pre-tensioning to the loop thread
• Added mocks for switches and motors, allowing testing w/o hardware
• Added tests for exosuit state changes

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Testing

Describe how you verified functionality:

• Unit tests added
• Existing tests pass
• Manual testing performed

Steps to reproduce/test:
1.
2.
3.

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Code Quality Checklist

Before requesting review, ensure:

• I ran make format
• I ran make test
• All CI checks pass
• Code follows project style & conventions
• New functions/classes include docstrings
• Public APIs are typed (type hints)

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Documentation

• Code comments updated
• README updated (if needed)

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Additional Notes

• Anything else reviewers should know?
• Attach outputs, plots, logs, or GIFs here.

[NGierden]

@claude-review

[claude]

Claude finished @NGierden's task in 2m 37s —— View job

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PR Review: Implement switches

• Gather context from PR description and changed files list
• Read changed source files (exosuit.py, gpio.py, motor.py, definitions.py, __main__.py)
• Read test file changes
• Analyze for bugs, correctness, style, and safety issues
• Post detailed review feedback

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Good structural direction — the state machine and mock infrastructure are the right foundations. However there are several bugs that need fixing before this merges.

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🔴 Critical Bugs

1. Motor copy-paste: motor_right never receives a command

exosuit.py lines 290–296:

self.motor_left.set_velocity(convert_rad_per_sec_to_rpm(command_left))

self.motor_left.set_velocity(   # ← should be motor_right
    convert_rad_per_sec_to_rpm(command_right)
)

The second call should be self.motor_right.set_velocity(...). The original copy-paste bug from signal_left was fixed, but a new one was introduced here for the motor output. Fix this →

2. motor_right.close() missing from _cleanup()

exosuit.py line 251 only calls self.motor_left.close(). The right motor is never closed, which will leave the serial/CAN connection open. Fix this →

3. PRETENSIONING loop has no sleep when torque is below limit — CPU spin

exosuit.py lines 304–314: if left_motor_torque < motor_torque_limit, there is no time.sleep() and the thread spins at 100% CPU. With the placeholder value 0.85 >= 0.85 this always triggers so it sleeps, but as soon as real torque reading is wired in and reads below the limit, this becomes a busy loop. Add a time.sleep() in the else branch (or unconditionally at the end of the loop body).

4. _pretension() races with the PRETENSIONING block in _loop()

_switch_event_handler calls _pretension() which sets velocity → 3. Then, within the same SWITCH_EVENT_HANDLER_INTERVAL window (0.5 s), the PRETENSIONING inner loop in _loop() detects torque >= limit (always true with placeholder) and immediately calls set_velocity(0). The motor is stopped before it can tension. These two threads are working against each other. The velocity-setting responsibility should live in one place — either _loop or _switch_event_handler, not both.

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🟡 Design / Correctness Issues

5. _loop() outer while True never exits for STOPPED state

exosuit.py line 263:

def _loop(self) -> None:
    while True:
        while self._status == ExosuitStates.RUNNING: ...
        while self._status == ExosuitStates.PRETENSIONING: ...
        time.sleep(EXOSUIT_STANDBY_INTERVAL)  # spins here forever when STOPPED

When status becomes STOPPED, neither inner loop matches and the outer loop sleeps 0.1 s indefinitely. _cleanup() joins this thread with a 2 s timeout and will always time out silently. Change while True: to while self._status != ExosuitStates.STOPPED:. Fix this →

6. Registering two add_event_detect calls on the same GPIO channel

exosuit.py lines 138–163 call add_event_detect twice for POWER_SWITCH (once for FALLING, once for RISING) and twice for TENSION_SWITCH. On real Jetson GPIO, a second call on an already-registered channel raises a RuntimeError. This will work with MockGPIO (each call just spawns a new thread) but will fail on hardware. Verify against the Jetson.GPIO API and restructure if needed (e.g., use BOTH edge if available, or use event_detected() in a polling thread).

7. No transition from PRETENSIONING → RUNNING

_switch_event_handler only handles:

• STANDBY → RUNNING (power on)
• STANDBY → PRETENSIONING (tension on)
• RUNNING → STANDBY (power off)
• PRETENSIONING → STANDBY (tension off)

If a user finishes tensioning (tension switch OFF) and then turns power ON, they go STANDBY → RUNNING correctly. But if they somehow end up in PRETENSIONING with both switches, or complete tensioning and immediately power on, there's no PRETENSIONING → RUNNING path. Consider whether this gap matches the intended hardware workflow.

8. _initialize_imus() ignores mock flag

With mock=True, IMUFactory.detect_and_create() is still called and will fail without hardware. The tests only pass if the IMU mock is already set up at the imu-python package level. If the package doesn't provide an in-process mock, tests on CI will fail or silently skip initialization. Consider adding a mock IMU path analogous to the mock motor.

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🔵 Minor / Style

9. MockMotor.get_torque() docstring is below the TODO (motor.py line 27) — docstrings must be the first statement in a function, before comments:

def get_torque(self) -> int:
    """Get the torque of the motor."""  # move above TODO
    # TODO: make this function name/param identical to the motor implementation
    return 0

10. MockGPIO.cleanup() missing return type hint (gpio.py line 56) — def cleanup(self): → def cleanup(self) -> None:

11. _power_on_callback and friends missing type hint for channel (exosuit.py lines 205–214) — channel should be typed as int.

12. SWITCH_ON / SWITCH_OFF are strings used as getattr keys (definitions.py lines 87–88) — this is fragile; the attribute names in MockGPIO must match exactly. Consider defining these as the integer constants directly in definitions.py (e.g., SWITCH_ON = MockGPIO.FALLING) or at least adding a comment explaining the coupling.

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Summary

Severity	Count
🔴 Critical (must fix)	4
🟡 Design/Correctness	4
🔵 Minor/Style	4

The mock infrastructure (MockGPIO, MockMotor) and the state enum are solid additions. The main things to fix are the motor routing bug (#1, #2), the pretensioning thread conflict (#3, #4), and the loop exit condition (#5) before this is ready to merge.

[NGierden]

See claude comments

[CatYang3]

Every Claude comment has been addressed in the last commits, except point 7:
It is intended that the RUNNING state and the PRETENSIONING state cannot transition to each other without transitioning to STANDBY first.