Guide DigiBus - Software Fan/Lights Controller Guide

Just sitting here on a bored night thinking; If you were to take the average of say 10 samplings of the fan speed wouldn't it be close to the actual speed?

 

Maybe... I was thinking the same thing too. But then thought I would need a complex circuit to do this, and I don't care what the speed of the fans are spinning at. As long as they are spinning

I think I will leave the definete answer to the hardcore (professionals) As I have no clue, and am an advanced nube, I think .


EDIT: Maybe it will work while the 12v pulse is being given to the fan. Just a thought.

 

One way round it I've seen is for the PIC to work out a theoretical speed, so if the fan is on half power it shows as 50% speed. Not ideal, but it's a reading if you want such things...

From Liquid Nexus

 

one method i was looking which i think had quite good accuracy (making a ir detector to test its acuracy is on my todo list) once per second, the power stays on full for 1/4 of a rotation of the fan (state change from rise to fall.) this is timed to deduce the fan speed.

 

First off, THANKS!!!

One quick question. I have 2 80mm Tornados (and I do get a nice warbling sound when I run them slow). When I do something that makes my cpu usage spike (i.e. maximizing or minimizing windows, resizing them, starting and stopping apps, etc.) my fan either runs at full speed or stops for just a second. I even set it to "realtime" in the task manager. Is it just me, or is this normal?

Sorry if somebody else already asked this question. I read the whole thread early today, and I don't remember seeing anything about it and don't fell like reading it all again tonight.

 

At very low speeds the warbling is normal on some fans.

If you load your CPU up its quite possible that one of the "segments" the frequency is made up of could hold on for longer than it should. This is because the program is designed to run in the background and alows your PC to do other things between pulses, which may take longer than the actual amount of time they are supposed to. THis shouldn't be noticable on a fast machine, at least most of the time.

The next version has plenty of options on how you want the program to construct the pulse along with timing and frequency resolution options, you should be able to iron on your problems with these.

 

thanks for the guide!!!

i acsidently changed a setting from 10 to 1000 and when i start up the advance edition it says "Run-time error '380' invalid property value" how do i cange it back plz?

 

Thought i trapped against that, damn.

You could try uninstalling the program and re-installing it. Or you could run this program.

I'll make sure it can't happen in the next edition.

 

I'm running a P4 2.4 with 512 dual DDR. how much of my resources will this take? I'm a gamer so I need to know that when I'm maxing out my PC with games like planetside or UT2K4 I won't be losing too much CPU power. also, in long load times will the fans get stuck in full speed or stop?

if you could answer 4 questions please, it would help allot.
1)on what system did you test it and how much %CPU power does it take?
2)will fan control get disrupted during heavy loads?
3)are the fans on or off by default? I mean when the program isn't running yet.
4)I searched www.arihav.com for the TIP120 and it only has a few other TIPxxx but not this one, I see you said the 122 is good too. is assembly any different?

thankyou.

 

You may notice the fans behave a little differntly, pehaps speed up ro slow down a little, but they should get stuck for a long period of time on your system.

AMD2100+, 512MB PC3200. 0% CPU Time according to the system monitoring programs i have (task manager, system monitor, etc).

It's possible, but load will have to be very heavy and very prolonged for you to notice any real change.

It totally depends on what motherboard you have, most of the ones i've tested it on leave all the port pins high until an application says otherwise, meaning all your devices will be on full until you run the program, this is quite convinient for most people.

Assembly will be the same for all of the NPN TIP transistors, TIP122 is a good choice. Make sure you get an "NPN" transistor though (most common), not a "PNP".

In the later version of the software which im developing now, you have almost complete control of how it simulates the PWM pulse, frequency, resolution, you can even select which method the software uses (the engine), some use less system resorces but aren't as fast or accurate, some use more but are very, very precise and smooth. Keep an eye out for that release, should be in a few weeks if all is wel.

 

acrimonious, do you know the frequency that you are switching at (I searched through the posts, but didn't see it)? I'm just curious as to what the period & frequency are... [edit] I'm assuming that the frequency would dip with higher cpu load, but any confirmation of this? [/edit]

-special [k]

 

Well, here we go.

I use a timer which interupts at a theoretical speed of every 10ms, for accuracy/individual-pc reasons you could take this to be 15ms max. Due to the resolution each interupt provides (in the version of the software you're using) this time represents 1/5th of the completed wave cycle, therefore 1 wave cycle takes 5*10ms = 50ms. To find the frequency you take 1 over the time period which gives you 1/50*10^-3 = 20 Hz

In the next version, as previously mentioned, you will have the option to increase or decrease this frequency. On my PC the port can give off about 130Khz at full (pc crashing) speed, the option to drive the fan at this speed is available in the next version .

 

Well, that would explain the "warbling sound"! 20Hz is pretty darn hard on the fans! But then again, using timers is notoriously inaccurate for some software. What are you using to write this with? (maybe you answered this already... if so, sorry!)

The one main problem with this "digibus" is that it is waaaay too cpu dependent. Assume that you leave a computer on with this software for, say, classes. If your computer crashes while the "digibus" has a fan in the OFF state, then you're screwed, especially if it is a CPU/GPU fan. Any way you would recommend preventing this sort of occurance?

Ohh, and also, have you looked into implimenting magic sine wave as one of the methods for your next version? It may be something to look into...

-special [k]

 

The idea of the DigiBus is to keep it as simple as possible, minimise circuitry, i have some schematics for an emercency override in the event of a hang. This would add alot of complexity to the design though. It's simple enough to solder a switch across the tranny in case of emergencies but if your leaving your PC unattended and have a crucial fan you can just run the fan at full speed (so if it hangs it will hang on a high) or just not connect it to the digibus at all basically.

The software is coded in VB 6 Pro, although some of the routines in the new version are in ASM, thats under testing though. The current version uses the crude VB timer control, but i've programmed in total 5 engines for it, which are much faster and more efficient, so it's upto you which to use.

I haven't looked into implimenting a "magic sine wave"..?

 

I have uninstalled it several times and reinstalled it but I’m still getting the error message. I have also run that reset program but I still get the error message! lol

When will u be releasing the new edition?

 

Very stange. You could search for "DigiBus" in your registry and try and correct the value, i've ordered everything nice.

New release will be a few weeks. Might release where i'm upto before then, but that'll be with out the ability to link system info to fan speeds (ie CPU Load to a fan speed or HDD load to a fan speed).

 

*drools at features of digibus*

I can't wait unitl I get some TIP120s. Then I shall be able to use all of my LED fans in my case. As For now, they have the 3 pin fan headers, and I am too lazy to make a dogdy PCB board with paper clips to connect em up.

 

ok il try that thanks!

 

just wondering, as a total electronics newbie, I saw someone use a capacitor to make lights in his keyboard fade out instead of just turn off when he let go of a button.

so, why not connect the TIP120 in parallel with another transistor that only allows electricity to pass when it doesn't get a signal at the base (PNP I think, always mix them up) and hook the second transistor to the same data line but with a capacitor in the middle.

if I understand this all correctly, won't this make the second transistor get a steady flow of electricity and be off all the time. but, when the system hangs in the off part of the cycle long enough, the fan will go at full speed.

I know this won't allow you to turn off the fan in question, but for the GPU or CPU fan it might work.

so, do I need to learn some more electronics or did I finally get something right?

 

how are things going with this project?

Is part # 3 of this guide nearly completed? How is the MBM compatible software coming?