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DriftKingTW / Raspberry-Pi-PWM-Fan-Control

Raspberry Pi PWM fan contorl (for Notcua PWM fans)
MIT License
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Question: FAN_MAX & MIN_TEMP <-> OFF_TEMP #12

Closed EagleeyeKai closed 2 years ago

EagleeyeKai commented 2 years ago

Hi there,

why is the constant FAN_MAX to be defined? It is not used in the code or do I miss something?

I have anther question regarding the MIN_TMEP and OFF_TEMP. What is the reason to define the OFF_TEMP constant? There is no case made if the temperature is between OFF_TEMP and MIN_TEMP which is 40 / 45 at default. Wouldnt it make sense to not use OO_TEMP and just stop the fan if the temp is below MIN_TEMP?

Thanks and best regards Kai

DriftKingTW commented 2 years ago

Hi Kai,

  1. FAN_MAX is originally design to turn on the fan fully when temperature reaches MAX_TEMP, it's not necessary if the FAN_HIGH sets to 100. We leave it there as an option that you can modify it to fit in different use case.

  2. MIN_TMEP and OFF_TEMP is for debouncing purpose. If you cut the fan off immediately when reaches MIN_TEMP, CPU temperature is very likely to go up again. Causing the fan to keep turning on and off. We need to make sure the CPU is cool enough to not to restart the fan in very short time.

Best, DriftKingTW