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feat(mcu): support Kalico non-critical MCU reconnection - #474
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Klippy log with minimal logging: 
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When the Cartographer MCU is configured as is_non_critical=true on Kalico and is currently disconnected, sending any cartographer_* command raised klippy.serialhdl.error, which klippy treats as an internal error and shuts down the printer. Pre-check mcu.non_critical_disconnected before each command send and raise RuntimeError instead. The integrator's _catch_macro_errors wrapper converts RuntimeError to gcmd.error, producing a clean user-facing message without shutdown. The check is a no-op on stock Klipper (attribute does not exist; getattr default is False).
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lgtm i've also updated the code in KalicoCrew/kalico#870 
Also did 2 regular prints after the reconnect which were fine too |
Move the non_critical_disconnected check from KlipperCartographerCommands into the KlipperCartographerMcu.commands property getter. Single guard site at the property boundary; every command access naturally short- circuits without per-call _check_connected() calls. Rename 'Mcu not initialized' to 'Cartographer MCU not initialized' for consistency with the disconnect message and to identify which MCU is affected when multiple are configured.
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Today I got "Unhandled exception during run" when my Cartographer disconnected mid-print, with plugin version 1.8.0. Seems like the issue is still present. |
your issue is likely not the plugin but Kalico itself. |
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Summary
Adds support for Kalico's non-critical MCU reconnection lifecycle. When a Cartographer MCU configured as
is_non_criticaldisconnects and reconnects at runtime, the plugin now re-initializes firmware constants, re-lookups commands, and re-validates/reloads models — without leaking resources or accumulating stale callbacks.This builds on #472 (graceful startup when disconnected) to complete the reconnection story.
Fixes #473
Decisions & callouts
_initializeis now idempotent:KlipperCartographerConstantsandKlipperCartographerCommandsare constructed once (guarded byis None), but theirinitialize()methods are called on every_initializeto re-read firmware values and re-lookup commands.getattrdetection forget_non_critical_reconnect_event_name/get_non_critical_disconnect_event_name. Both must be present for handlers to register — this matches Kalico's API where both are always provided together.try/exceptto prevent a failing callback from breaking Kalico's reconnection flow._register_data_response()is called on every_initialize. This is safe because Klipper'sregister_serial_responsereplaces existing handlers rather than accumulating them.Testing
Install this branch for testing:
is_non_critical = true, disconnect and reconnect the Cartographer MCU — plugin should re-initialize and resume normal operationKnown issue
If the Cartographer MCU is disconnected, Klipper firmware is restarted, and then the MCU is plugged back in, Kalico's reactor crashes with
Failed automated reset of MCU 'cartographer'raised fromnon_critical_recon_event. This is a Kalico-side bug — the timer callback atklippy/mcu.py::non_critical_recon_eventdoes not catch theerrorraised byrecon_mcu()/_connect(), so it escapes toprinter.runand shuts klippy down. Tracked upstream as KalicoCrew/kalico#870.The reverse order (disconnect → reconnect, no FW restart in between) works correctly with this PR.