Banana pi R3 fan with PWM

Why not use a mosfet module on any of the available gpio pins on the gpio header? No need to solder on the board. Like this one, it is not very expensive:

mosfet @ aliexpress

Ha1930cf6bf8d448489ff614f33d5a8e0u

And get the 12V, soldering on a cable like this:

H89ad0d926f3542e38d0c48891e079096w

Thanks, I know I have many options to solve this problem with additional hardware/connectors, but I wanted to try a software solution.

All I need is a timer. I bet it can be done easily in kernel space.

Hello, this is my first post on this forum. I want to share my experience. I did some tests using small heatsinks on chips and the open case. I get the following readings from internal sensors in standby (no devices connected on WiFi) with a room temp of 20C:

phy0 2.4Ghz -> 68C phy1 5Ghz -> 43C

On the SoC the reading by internal sensor is 45C.

The temperatures detected with a thermal scanner (my bet was 3-4C low) are:

on 2.4Ghz -> 37.1C on 5Ghz -> 40.5C

On the Soc I get 45.5C.

It seems to me that the SW reading by sensor on 2.4Ghz chip is not so correct.

Please report this on

Is it possible to read temp of wifi-chips directly from sysfs?

Edit: found possible solution here

cat /sys/class/ieee80211/phy*/hwmon*/temp1_input

Done! I hope this can be checked.

Link to issue: https://github.com/openwrt/mt76/issues/729

First of all, thank you for the many helpful comments which helped me with my decisions.

In my setup, I deactivated the wifi chip by unloading the mt7915e module, because I donā€™t need it. This dropped the heat development a bit. I only use the Banana Pi as a gateway for my 1GBit fiber optic connection for netflow traffic analysis.

To do this, I glued individual heat sinks to each chip with thermally conductive adhesive. All packed in a metal case. Drilled a hole in the cover and inserted a 5V PWM fan.

This usually runs at the lowest inaudible speed and is controlled by pwm. The temperature of the CPU is 26Ā°C in a performance/stress test and the SFP connector is 36Ā°C.

here is my part list:

Metal case: https://de.aliexpress.com/item/1005004885309544.html

SFP Transceiver Modul: https://www.fs.com/de/products/20140.html

Heat Sink: https://amzn.to/3j1ojQy

Fan: https://amzn.to/3D0pCGk

Fan grille: https://amzn.to/3Xrec6R

Thermal adhesive: https://www.webshop-innovatek.de/waermeleitmittel/waermeleitkleber/701/high-silver-waermeleitkleber-2x-4-g?number=501909-01

index1 index2 index3

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What is the OS? I have also 5V Noctua with PWM and the fan runs for just 5 second during boot and stops after that. What is the reason about that? Thank you.

i guess your board does not reach the temperature where fan is activated :slight_smile:

to activate pwm, you have to call

echo 1 > /sys/class/thermal/cooling_device0/cur_state

and my OS is lates openwrt trunkā€¦ but it does not matter for pwm.

2 Likes

Thatā€™s the answer I was looking for. Thank you!

Possible hw improvement would be adding a switch like bootswitches in v1.0 for R317/R318 to select fan voltage without soldering.

@sinovoip is this possible?

Iā€™ve only seen heatsinks with fan and 43mm hole pitch using a 12v fanā€¦no 5v fan. Ordered 2 5v pwm fans and heatsinks without holes to drill holes and cut a thread.

I just ordered the Noctua. Iā€™m contemplating to buy a northbridge heat sink and remove the fan to screw the Noctua on the heatsink, if it does not work Iā€™ll do your setup.

If I do that, what is the diameter of the hole you pierced in the case for the fan, and what is the bit size for the drill for the screw holes?

I have a 40x40mm fan,drilled a 36mm hole for fan and 3mm for the screws

I did something similar. I have mounted a heatsink of about 60x70mm, drilled a 28mm hole on the case and put a 30mm 5v fan in it. The temperature is now about 33 degrees Celsius (with the room at 20 degrees). I have now ordered a second BPI-R3 and I think I will do something similar for the fan but will probably use small single chip heatsinks.

I just received the Noctua PWM. There are 4 wires on the fan, 3 on the board. I see that you selected one of the 2 blue wires. Does it matter which one you take?

noctua

it is the green one, you donā€™t need.

but before you finally cut the cable, test it :wink:

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What is the best way to persist this after reboot?

I confirm this. I have

sensors 
mt7915_phy1-isa-18000000
Adapter: ISA adapter
temp1:        +63.0Ā°C  (high = +120.0Ā°C, crit = +110.0Ā°C)

mt7915_phy0-isa-18000000
Adapter: ISA adapter
temp1:        +41.0Ā°C  (high = +120.0Ā°C, crit = +110.0Ā°C)

With my thermometer gun, I read 40C max.