Raspberry PoE-HAT Fan Speed

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The_Raven
Posts: 18
Joined: Sat Aug 12, 2017 12:51 pm

Raspberry PoE-HAT Fan Speed

Post by The_Raven »

Hi all

I have a Raspberry Pi 3B+ with a PoE-HAT.
The HAT has a fan on it.
On raspian it's possible now to control the speed with a config-parameter in the config.txt:
dtparam=poe_fan_temp0=55000,poe_fan_temp1=60000
This turns on the fan @ 55C°.
I have tried this on dietpi, but i think it does not work.
Should this work or not?

Thx an greetings
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MichaIng
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Joined: Sat Nov 18, 2017 6:21 pm

Re: Raspberry PoE-HAT Fan Speed

Post by MichaIng »

@The_Raven
DietPi uses the official Raspberry Pi kernel and firmware, so yes this should totally work.

The board communicates to the HAT via I2C, so you need to enable it, e.g. via dietpi-config > Advanced Options > I2C state
Or temporarily to the running system:

Code: Select all

dtparam i2c_arm=on
Check if this enables the kernel module automatically:

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lsmod | grep 'i2c-dev'
Otherwise enable manually:

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modprobe i2c-dev
The following should then show the active I2C device:

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ls -Al /dev/*i2c*
The_Raven
Posts: 18
Joined: Sat Aug 12, 2017 12:51 pm

Re: Raspberry PoE-HAT Fan Speed

Post by The_Raven »

Thank you very much for your reply.

The short version:
It works out of the box. You don't need to activate i2c module.

The longer version:
It was my "fault". The pi was in a "closed case". So there was no real airflow. Because of this, the temp was always high and i thought the config parameter is not working (fan was always on). Now i made some holes in the case to make an airflow possible.
And tata, it is working now!
Sometimes it is better to sleep one night over it then asking right now in the forum. :roll:
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MichaIng
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Re: Raspberry PoE-HAT Fan Speed

Post by MichaIng »

@The_Raven
Ah okay perfect. Yeah the fan should be at best included into the case, so have it's own whole where it sits inside. Also smaller wholes are very suboptimal, limiting the airflow.

Here that you get an idea how this should look like:
Image
The_Raven
Posts: 18
Joined: Sat Aug 12, 2017 12:51 pm

Re: Raspberry PoE-HAT Fan Speed

Post by The_Raven »

No so easy, it is a PoE-Powerd Control-Unit to control my audio system and video survey ;)
control-unit.JPG
This case has normal no holes. And maybe it is not designed to work with PoE :roll:
But hey, it's a pi-project! So everything is allowed :lol:
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MichaIng
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Re: Raspberry PoE-HAT Fan Speed

Post by MichaIng »

Ah yeah forgot again that it's about the fan on the HAT and not on the Pi itself. Not sure about additional heat of the PoE HAT but since it comes with fan and fan speed stays high closed case, it seems to be required.

You could run cpu to check temps and see if it is okay with your current solution. Generally if there is already a fan, its airflow path should be as free as possible. Closing it too much could even lead to better without fan than with, since the fan itself also consumes power => produces heat ;).
bequflo
Posts: 10
Joined: Thu Sep 10, 2020 3:00 pm

Re: Raspberry PoE-HAT Fan Speed

Post by bequflo »

Hi everyone

I have a Raspbeyy Pi 4 whith 4Gb of RAM and i have installed a POE Hat after that does not connect on eth0 or wlan0 if i remove it all works fine. do think a driver is missing?
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Joulinar
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Joined: Sat Nov 16, 2019 12:49 am

Re: Raspberry PoE-HAT Fan Speed

Post by Joulinar »

does the board is powering up at all? Means led's flashing? Are you able to attach a screen to check what going on?
Pls let us know if a solution is working. This could help others if they hit by similar situation. Your DietPi Team
bequflo
Posts: 10
Joined: Thu Sep 10, 2020 3:00 pm

Re: Raspberry PoE-HAT Fan Speed

Post by bequflo »

hi again. Yes, the system is up an funcional whit keyboard and monitor but can't link over eth0 or wlan0
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Joulinar
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Joined: Sat Nov 16, 2019 12:49 am

Re: Raspberry PoE-HAT Fan Speed

Post by Joulinar »

can you have a look to dmesg and journalctl if you see some messages regarding the network interface. What happen if you run ifup eth0
Pls let us know if a solution is working. This could help others if they hit by similar situation. Your DietPi Team
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