Fix ND-1000 on macOS: tolerant clear_halt + lamp-off reset - #1252
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rickwierenga merged 1 commit intoSep 10, 2026
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Two fixes found by testing on a physical ND-1000 on macOS: - _configure_usb_device: on macOS libusb raises "Entity not found" for an endpoint that is not actually halted, crashing setup(). Make clear_halt best-effort per endpoint (seabreeze, the reference Ocean Optics stack, does not call it at all). - stop(): the command-based lamp-off ([0x03, 0x00]) is unreliable on this device's firmware and intermittently leaves the lamp on. Add a USB reset at teardown (as the original driver did) to clear the lamp latch deterministically. Re-enumeration is harmless at teardown; verified the lamp reliably switches off and reconnection still works. Verified on hardware: drives the device and measures a correct paracetamol UV spectrum (lambda-max ~243 nm). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018b3SXMWSzNMuNe6S48Yk7m
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Tested #1166 on a physical NanoDrop ND-1000 on macOS — it drives the device and measures a correct paracetamol UV spectrum (λmax ≈ 243 nm). Two small fixes were needed, both in
pylabrobot/thermo_fisher/nanodrop_1000/nanodrop_1000.py(+14/-3):clear_haltcrash on macOS — libusb raises[Errno 2] Entity not foundfor an endpoint that isn't actually halted, which crashessetup(). Made it best-effort per endpoint. (python-seabreeze, the reference Ocean Optics stack, doesn't callclear_haltat all.)Lamp not switching off — the command-based lamp-off (
[0x03, 0x00]) is unreliable on this device's firmware and intermittently leaves the lamp on. Restored a USB reset at teardown (as Jordvl's original driver did), which clears the lamp latch reliably. Re-enumeration is harmless at teardown.Windows setup steps (Zadig / BOS reg key) untested — no Windows machine here.
Full write-up with plots + raw data: https://github.com/vcjdeboer/nanodrop-pylabrobot-demo
🤖 Generated with Claude Code
https://claude.ai/code/session_018b3SXMWSzNMuNe6S48Yk7m