Hi All,
I recently hooked up some Noctua 4-pin PWM fans to an Arduino Uno to enable Sim Wind via SimHub.
They power fine, and change speed but there just seems to be a huge lagging of the airflow/fan speed to that of the game's actual speed.
The only thing I can think of is that the slowing down or the ramping up of the fans isn't instantaneous due to inertia. (The data with SimHub is exporting doesn't have any lag associated with this, so this leads me down to a fan issue rather than SimHub)
Has anyone taken any steps to improve this as I've tried playing around with gain and gamma settings to no avail.
Hope someone can help!
Regards.
Hi ! It's indeed totally related to the fan characteristics, the signal has a 16ms~ latency on the licensed version (otherwise 100ms) so it's totally unsensible for this application. Most low to medium fans will ramp up in a few seconds (1 to 2/3 seconds). Strong server/mining fans (7000RPM) I had in hands reacts much faster (500ms I would say, I've not explicitely measured it :D).
Nicolas
Thank you for your reply!
Do you think changing the threshold and minimum force values would at least help reduce the feeling of lag?
Regards.
Minimum speed will indeed reduce the variation between low speed and high speed, but it will reduce the contrast too. Threshold would make it worse as it will make the fan start later.
A combination of both could be a good compromise, it's worth testing.
PS : Noctua is know for their silent fans, I guess heavy speed smoothing (and big latency) is part of the "silent" strategy.
I'm with you.
That makes a lot of sense!
I've been thinking about the PWM method and how the fan slows down.
I'd presume that if the fan is at 100% and needs to drop to 50% the PWM would just set to 50% immediately and coast down to the 50% RPM.
During this time, the fan is still applying a force to the fans (50%) and therefore the slowing down would be slow-ish.
However, if the PWM was to go to from 100% to 0% and only come back on at 50% once it's at 50% RPMs, that would be a much quicker way to decelerate the fan?
So with that in mind, is it possible to hook up the tach pin to the Arduino and for it to 'self sense' and only output an active PWM speed once it's decelerated to (or below) the value required?
This could be far outside the realms of SimHub (or indeed possibility) but I thought it worth an ask as SimHub is an incredible piece of software to begin with.
Regards.
Jumping on this thread. Ive been trying to run through the fixes suggested here. My issue is that the fans are running up to speed but get to speed then cut out and run back up to speed again. There doesn't appear to be any relationship to sim kph speed. There no movement at below 58% and I've set the frequency of fans on motor shield in set up at 300 which seemed to give the best sustained run time but still only a few seconds.