Same bug class as the earlier heater fix: TempSensorTask.on_process()
called self.sensor.temperature() every tick with no exception handling
at all, and the constructor even called it once synchronously at
startup to prime the value. A read failure there would either crash
the whole server before the event loop started, or permanently kill
TempSensorTask's coroutine mid-run - nothing restarts a dead ATask, so
the sensor would never be read again for the rest of the process's
life.
TempSensor_max31865.temperature() now catches read failures and calls
a new reopen() (closes/reopens the spidev handle - the closest
equivalent to unplug/replug for a bus peripheral) instead of raising,
holding the last-known-good reading meanwhile. reopen() itself never
raises either, learned from HendiCtrl.disconnect() previously letting
a failure escape the same way. Belt-and-suspenders guards added at the
TempSensorTask level too, matching HeaterTask/StirrerTask.
Verified against a fake spidev: a read failure no longer raises,
reopen() is attempted automatically, and readings resume once the bus
responds again - even when reopen() itself also fails.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YaPLuRPpyjWcwhMvCvpHCL
jensandClaude Sonnet 5
4b9a144b62