Juggler00
Posts: 6
Joined: Tue May 03, 2016 1:40 am

PoE HAT - noisy fan

Sun Jan 06, 2019 8:09 pm

I have the official Raspberry Pi PoE HAT and am running a fully-updated Raspbian. I am noticing that the fan on the PoE HAT is very noisy. It appears to spin up to 100% every 10-20s, run at 100% for ~60s then repeat.

I did some searching on the forums and have seen some comments on how to alter this behaviour. I’m looking for the actual, proper way to do this. Can anyone help?

ShiftPlusOne
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Re: PoE HAT - noisy fan

Mon Jan 07, 2019 6:57 am

Out of curiosity, what's the ambient temperature of the room and what's the pi doing when the fan kicks in, if anything?

Edit config.txt and add the following line:

Code: Select all

dtparam=poe_fan_temp0=80000,poe_fan_temp0_hyst=5000,poe_fan_temp1=82000,poe_fan_temp1_hyst=2000
That should change the behaviour so that the fan turns on at 80C, turns off when it comes back down to 75C. If the temperature reaches 82C it will go full blast until it drops back down to 80C. You can play with the values and adjust them so that they suit you.

https://github.com/raspberrypi/firmware ... ADME#L1649
Juggler00 wrote: It appears to spin up to 100% every 10-20s, run at 100% for ~60s then repeat.
It shouldn't go to 100% right away, but let's check if the instructions above help before diagnosing further.

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Imperf3kt
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Re: PoE HAT - noisy fan

Mon Jan 07, 2019 11:44 am

I thought the fan could only be controlled between 60 and 70 degrees. Is it now possible to force it to any desired value?
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ShiftPlusOne
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Re: PoE HAT - noisy fan

Mon Jan 07, 2019 12:21 pm

The behaviour of the fan could always be defined by the user. The most recent change (a few months back) was to make the temperature and hysteresis values easily adjustable through config.txt, to cover most use cases without having to rebuild a device tree overlay.

Juggler00
Posts: 6
Joined: Tue May 03, 2016 1:40 am

Re: PoE HAT - noisy fan

Mon Jan 07, 2019 2:35 pm

The room is at 21ºC, so nothing extreme. I'm running ser2net on the Pi so that my instance of HomeAssistant sees the USB z-wave stick attached to the Pi as a local device. This does increase the network traffic, so I'm wondering if that could be causing the "freak out"?

I've made the changes to config.txt; so far so good. Thanks!!!
ShiftPlusOne wrote:
Mon Jan 07, 2019 6:57 am
Out of curiosity, what's the ambient temperature of the room and what's the pi doing when the fan kicks in, if anything?

Edit config.txt and add the following line:

Code: Select all

dtparam=poe_fan_temp0=80000,poe_fan_temp0_hyst=5000,poe_fan_temp1=82000,poe_fan_temp1_hyst=2000
That should change the behaviour so that the fan turns on at 80C, turns off when it comes back down to 75C. If the temperature reaches 82C it will go full blast until it drops back down to 80C. You can play with the values and adjust them so that they suit you.

https://github.com/raspberrypi/firmware ... ADME#L1649
Juggler00 wrote: It appears to spin up to 100% every 10-20s, run at 100% for ~60s then repeat.
It shouldn't go to 100% right away, but let's check if the instructions above help before diagnosing further.

80ov
Posts: 2
Joined: Tue Feb 26, 2019 11:18 am

Re: PoE HAT - noisy fan

Tue Feb 26, 2019 11:26 am

ShiftPlusOne wrote:
Mon Jan 07, 2019 12:21 pm
The behaviour of the fan could always be defined by the user. The most recent change (a few months back) was to make the temperature and hysteresis values easily adjustable through config.txt, to cover most use cases without having to rebuild a device tree overlay.
On what the kernel does it work? I have 4.14.9x. After adding a line
dtparam=poe_fan_temp0=80000,poe_fan_temp0_hyst=5000,poe_fan_temp1=82000,poe_fan_temp1_hyst=2000
in to /boot/config.txt - raspberry did not boot after reboot.

ShiftPlusOne
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Re: PoE HAT - noisy fan

Tue Feb 26, 2019 4:53 pm

80ov wrote: On what the kernel does it work? I have 4.14.9x. After adding a line
dtparam=poe_fan_temp0=80000,poe_fan_temp0_hyst=5000,poe_fan_temp1=82000,poe_fan_temp1_hyst=2000
in to /boot/config.txt - raspberry did not boot after reboot.
Should work on all relatively recent kernels.

I've just tested it with rpi-update a08ece3 (4.14.98) and it seems to work.

Unrelated to this, but I've just noticed that config.txt dtparam lines seem to have a character limit. poe_fan_temp1_hyst=2000 is cut off, so you may wish to split it into two lines:

Code: Select all

dtparam=poe_fan_temp0=80000,poe_fan_temp0_hyst=5000
dtparam=poe_fan_temp1=82000,poe_fan_temp1_hyst=2000

80ov
Posts: 2
Joined: Tue Feb 26, 2019 11:18 am

Re: PoE HAT - noisy fan

Tue Feb 26, 2019 5:26 pm

ShiftPlusOne wrote:
Tue Feb 26, 2019 4:53 pm
80ov wrote: On what the kernel does it work? I have 4.14.9x. After adding a line
dtparam=poe_fan_temp0=80000,poe_fan_temp0_hyst=5000,poe_fan_temp1=82000,poe_fan_temp1_hyst=2000
in to /boot/config.txt - raspberry did not boot after reboot.
Should work on all relatively recent kernels.

I've just tested it with rpi-update a08ece3 (4.14.98) and it seems to work.

Unrelated to this, but I've just noticed that config.txt dtparam lines seem to have a character limit. poe_fan_temp1_hyst=2000 is cut off, so you may wish to split it into two lines:

Code: Select all

dtparam=poe_fan_temp0=80000,poe_fan_temp0_hyst=5000
dtparam=poe_fan_temp1=82000,poe_fan_temp1_hyst=2000
Great, it worked!
Спасибо!

ShiftPlusOne
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5578
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Re: PoE HAT - noisy fan

Tue Feb 26, 2019 6:00 pm

80ov wrote: Great, it worked!
Спасибо!
Glad to hear it.

Незачто!

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