[fan] More control over HDR fan

af123

Administrator
Staff member
The fan's controlled via a pulse width modulator on the Broadcom SoC. The humax varies the 'On Interval' to change the speed. Fan speed is directly related to HDD temperature but the Humax software only reads the temperature (and varies the fan if necessary) every two minutes. Observed levels with version 1.02.32 are:

When the temperature rises to 55 degrees, on-interval is set to 176
when it falls to 54, on-interval becomes 162
when it falls to 51, on-interval becomes 138
when it falls to 49, on-interval becomes 0 (fan turns off again).

I've also seen it set the on-interval to 200 once and I've tried 255 myself which does run the fan even faster. Maintenance mode in the new CFW 2.19 runs it at 176 which is a little noisy but should stop the HDD from heating up.

I'm building a new package called fan which will allow people to specify a minimum fan level as it has been requested in the past. It's possible that running it permanently at 138 or even lower would stop the drive ever heating up to 55. I prefer it to be silent for the first hour or two but I'm sure some other people wouldn't even notice the low fan speed all of the time but don't like it bursting into life at maximum speed.

My box goes through a fan cycle about once per hour:

Code:
Thu Sep 12 09:12:03 2013 Fan level: 0 -> 176 (0 -> b0)
Thu Sep 12 09:14:03 2013 Fan level: 176 -> 162 (b0 -> a2)
Thu Sep 12 09:20:03 2013 Fan level: 162 -> 138 (a2 -> 8a)
Thu Sep 12 09:30:03 2013 Fan level: 138 -> 0 (8a -> 0)
Thu Sep 12 10:06:03 2013 Fan level: 0 -> 176 (0 -> b0)
Thu Sep 12 10:08:03 2013 Fan level: 176 -> 162 (b0 -> a2)
Thu Sep 12 10:16:03 2013 Fan level: 162 -> 138 (a2 -> 8a)
Thu Sep 12 10:24:03 2013 Fan level: 138 -> 0 (8a -> 0)
Thu Sep 12 11:00:03 2013 Fan level: 0 -> 176 (0 -> b0)
Thu Sep 12 11:04:03 2013 Fan level: 176 -> 162 (b0 -> a2)
Thu Sep 12 11:08:03 2013 Fan level: 162 -> 138 (a2 -> 8a)
Thu Sep 12 11:18:03 2013 Fan level: 138 -> 0 (8a -> 0)


Note: The first few posts following this one were originally in the CFW 2.19 thread so were written before this package was announced.
 

Kev_w

Member
Is the fan control limited to maintenance mode? I'd love to experiment with different fan settings during normal use - ie try to stop it going full blast every 30mins!

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Scrat

May contain acorns
Is the fan control limited to maintenance mode? I'd love to experiment with different fan settings during normal use - ie try to stop it going full blast every 30mins!

I don't understand this as I am never aware of any fan sound.
 

Kev_w

Member
I think there is some variability between boxes regarding the fan noise. The fan has 3 or 4 different speeds it runs at. Mine is silent when at speed 1 or 2 but is audible in a quiet room when it goes faster.
It's likely that other boxes either don't get as hot or have quieter fans overall.


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Black Hole

May contain traces of nut
I don't understand this as I am never aware of any fan sound.
The idea is that by establishing a not-off minimum fan speed, the internal temperature of the HDR-FOX can be prevented from building up. The native algorithm is to leave the fan off until the temperature reaches an upper threshold, then turn the fan on full blast* and only throttle it back as the temperature falls through various thresholds. More info available HERE (click).

* "Full blast" is not literally the fastest the fan can run; af123 has established it is about two-thirds power and that there is a (little seen) control level at a higher power still. The speed the fan is running at has a dramatic effect on the noise level.
 
OP
af123

af123

Administrator
Staff member
The fan speed is directly linked to hard disk temperature so there will be variation in hard disks too. I'll start a new thread for the fan package I'm writing and put some more details there.
 

Scrat

May contain acorns
The fan speed is directly linked to hard disk temperature so there will be variation in hard disks too. I'll start a new thread for the fan package I'm writing and put some more details there.

Thanks. Just tried turning the box on in a quiet room. Although I can hear the whir of the HDD and its chuntering around its tracks, I can hear no fan sound whatsoever. I have never been aware of a fan sound. The box is sandwitched between a FoxSat HDR and a YouView box in a warm room, so it is not particularly well ventilated there.
 
OP
af123

af123

Administrator
Staff member
Thanks. Just tried turning the box on in a quiet room. Although I can hear the whir of the HDD and its chuntering around its tracks, I can hear no fan sound whatsoever. I have never been aware of a fan sound. The box is sandwitched between a FoxSat HDR and a YouView box in a warm room, so it is not particularly well ventilated there.
The fan doesn't come on until the hard drive temperature hits 55 centigrade. That takes up to two hours from a boot with my boxes.
 

Black Hole

May contain traces of nut
We have known some boxes to have a broken fan. One of the first acceptance tests I did on my newer HDRs was to check their fans came on.

Take a piece of thin paper (a page from a magazine is good) and cut a rectangle about 2x3", and fold a half inch strip to a right angle. This will then balance on the back panel (with the lip on the top surface) to obstruct the fan vent. If the fan comes on it will blow the paper tell-tale away. If the paper is still there after a few hours running, there is something wrong (my tests in reasonable ventilation had the fan coming on within half an hour).

Alternatively (or as well), run the sysmon package (this has been fixed - it used to take too much CPU time). If the temperature graph shows the HDD never reaching 55, the fan won't come on anyway. On the other hand, if the reported HDD temperature never reaches 55, is there something wrong with the temperature sensor?
 

Wallace

Traveler 34122
You could just use the Sysmon graph in the WebIf to chart the rise, and hopefully, the fall of the temperature as the fan kicks in at 55deg.
 
OP
af123

af123

Administrator
Staff member
I suspect BH did his acceptance test prior to installing the CFW but, yes, the sysmon graph is perfect for this.
 

Black Hole

May contain traces of nut
The last two posts crossed my edit, sorry :)

Yes, delivery acceptance trials need to be performed before any mucking about!
 

Kev_w

Member
We might look at a fan upgrade as well as a software solution

I sense I've taken this thread a bit off topic (sure the mods won't mind tidying up ;-) )

I've looked at buying a new fan. Unfortunately high quality 50mm fans appear hard to come by and the connector to the humax pcb is non-standard meaning quick tests of new fans is hard (need to remove connector from original fan and solder to new).
Ideally I'd make a conversation cable but am struggling to find a supplier for the connector that humax used.

EDIT: bought stuff to make a conversation cable. Still can't find the small connector humax use so it will mean slightly modifying the original fan (removing the small connector and fitting a standard one - then fitting the original connector on an extension cable...).

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Black Hole

May contain traces of nut
I sense I've taken this thread a bit off topic (sure the mods won't mind tidying up ;-) )
IMO an addition to the title would be sufficient: "... / Fan Speed"

NB: The relevant posts (including this one) have since been relocated.
 
OP
af123

af123

Administrator
Staff member
I'd prefer to start a new fan topic and leave this thread for CFW 2.19 issues/notes.

Edit: there are some old fan topics but they're probably best left alone.

Posted on the move; please excuse any brevity.
 
OP
af123

af123

Administrator
Staff member
I am developing a new package which will allow more control over the HDR fan and in the process I have been able to determine more details about the default behaviour (see next post). The package is not yet available in the repository but the recent release of CFW 2.19 has already sparked some discussion.
 

Kev_w

Member
My box does 4 cycles an hour - possibly due to poor ventilation.
Looking forward to experimenting :)

I find the current behaviour a little odd - I'd assumed that the fan scaled up slowly with temperature instead of closing the stable door after the horse has bolted.

Don't really see the point of having different speed settings if they are only going to use them as the hdd cools - might as well just be on/off.

As I say - looking forward to experimenting :)

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Ezra Pound

Well-Known Member
I'm wondering if the fan is started on 'Full' to make sure it spins up reliably, maybe starting at say 25% is unreliable
 
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