Banana pi R3 fan with PWM

[Rooot]

@brainstorm

mt7915_phy1-isa-18000000
Adapter: ISA adapter
temp1:        +78.0°C  (high = +120.0°C, crit = +110.0°C)

i’m the only one with a mt7915_phy1-isa-18000000 reporting 15°c ??

is +78.0°C a correct value ??

[frank-w]

@brainstorm

I think it’s a shame that more conservative defaults are not applied since the case was fairly warm to the touch and could have damaged my system eventually… in other words: out of the box configs should not self-destruct the router

Sorry, i made a mistake when upstreaming the r3 thermal part dts due to my 3rd party pwm was not working with r3.

But you should be aware that mainline software support is done by only a few people,mainly daniel (also openwrt),wifi/hw offloading from lorenzo and some basic parts from me. These are development boards

[brainstorm]

Argh, sorry for my harsh word actually, “shame” is a bit too strong in this context, I should have used “pity”. If you show me how to modify the dts, I’d be happy to PR the changes to OpenWRT as penitence

Thanks Frank and others to maintain/fix those systems, I totally appreciate the efforts… I bought that board, so at least, I hope that helped somehow

[brainstorm]

I’d definitely wouldn’t take those 78degC too seriously…

[Lorem_amicus (Michael Fischer)]

Hello,

because of looking for a new PWM fan, I also thought about a new heatsink … . I know there is a fan for R3 but I may want to work with thermal paste. At the end it could be that I create a fansink which covers the whole area including SFP and 4G cellular modem. But this is just a dream…

Anyway, I tried to measure more exactly the chips height beneath the heatsink. I still have no digital caliper. But I got the information from internet and from a “piece of paper measurement”.

I know it sounds crazy, but after one day of thinking (How could I find something in my room that could measure in 0.1 mm steps), I realized and find out, that a piece of paper (HP Premium 90g/m^2) has 0.12 mm thickness . And because of the plain surface of the chips it is possible to use a ruler to get the differences between package heights. YES, crazy!

The measurement results matches really good with the information from internet. These is the summary:

The minimal thermal pad thickness is 0,5 mm (MT7531AE blue). After covering the chip packages surface with thermal pads, the heights should be 2,1 mm at all chips.

If something is wrong (heights, package, dimension), please write back to me!

Finding the dimensions of the different chip packages was not easy. It would be good if Banana pi could upload this data to the wiki.

[Lorem_amicus (Michael Fischer)]

Hallo again,

I learned some things about my fan(s) and frank’s post at R4 topic pushed me a bit:

Banana Pi BPI-R4 Wifi 7 router board with MediaTek MT7988A (Filogic 880),4G RAM and 8G eMMC

You are right that pwm fans normal have 4 pins because the 3rd pin is sense to read speed. But this is not used on r3/r4 and maybe can connected to a gpio. I have tried 3rd party pwm fan on r3 and it does not work. I guess problem was that it was a 5v pwm and r3 supplied only 3v3 on pwm…so only bananapi fans work here

First of all, I learnd that not only the PWM signal on the board is importand. I learnd that a PWM fan has microships inside which can effect the result.

I have two fans. This are my results overview with 5V and 12V:

The only fan which could be switched off was the PLD05010S12H @ 5V.

Next try would be a PLD06010S12L 55mm 0,2A. I have already ordered the fan. Should be here within a month …