Banana pi R3 fan with PWM

Sandokan · January 12, 2023, 7:19pm

Done! I hope this can be checked.

frank-w · January 12, 2023, 8:01pm

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

holger.hees · January 21, 2023, 8:04am

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 don’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 26°C in a performance/stress test and the SFP connector is 36°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

groms · January 27, 2023, 4:20pm

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.

frank-w · January 27, 2023, 4:22pm

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

holger.hees · January 27, 2023, 4:33pm

to activate pwm, you have to call

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

and my OS is lates openwrt trunk… but it does not matter for pwm.

groms · January 28, 2023, 9:07am

That’s the answer I was looking for. Thank you!

frank-w · February 12, 2023, 8:11am

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?

I’ve only seen heatsinks with fan and 43mm hole pitch using a 12v fan…no 5v fan. Ordered 2 5v pwm fans and heatsinks without holes to drill holes and cut a thread.

coding123 · April 10, 2023, 5:20pm

I just ordered the Noctua. I’m contemplating to buy a northbridge heat sink and remove the fan to screw the Noctua on the heatsink, if it does not work I’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?

frank-w · April 10, 2023, 5:26pm

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

Sandokan · April 10, 2023, 7:08pm

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.

coding123 · April 11, 2023, 8:24pm

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?

holger.hees · April 12, 2023, 8:54am

noctua

it is the green one, you don’t need.

but before you finally cut the cable, test it

coding123 · April 13, 2023, 7:39pm

What is the best way to persist this after reboot?

coding123 · April 13, 2023, 7:45pm

I confirm this. I have

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

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

With my thermometer gun, I read 40C max.