G5 Uni-Controller (What Do You Think?)

[timvrakas]

I finished my G5 Mod Recently and it turned out very well.
However I was frustrated by the following parts:

• Front Panel Harness: Firewire dosen't work after 3 re-do's!
• no way to interface those internal temp sensors
• FANS: AAGGGHH! i am disappointed by the lack of thought of some people who think the G5 fans are crapy, loud, not PWM! They are all of that, and more! the issue is the are PWM at a different frequency than ATX case fans. When you buy a 1000$+ Mac it dosen't come with **ity fans! they are large CFM, but designed to work at low speed. I can get Speed control with standard PWM off an AT-Mega Arduino!

But i forgive you all.....

SO NOW! I have this idea for a one-of-a-kind system controller for G5 Mods:

• jack for front panel harness
• ATX USB, Front light/Swich, Firewire, Audio cables.
• on board COM Port Header for MoBo
• Headers for all G5 Fans
• Molex Power for fans
• connector for case temp sensors

so what you're looking at here is a front panel re-router coupled with a Serial fan controller and temp sensor. all the fan data and temp data is sent through the COM port.

Here is what i need from Y'all:

• What you think of this idea.
• help writing an extension (kext) that uses the COM Port to control fans (or even a link)

 

[dsiglin]

I think if you can do it, do it!

 

[timvrakas]

How Helpfull

 

[chaosdesigns]

I am a Mac software engineer and I don't think you want to waste CPU cycles on monitoring temps and controlling fans. This is more a job of a dedicated circuit, IMHO.

chaos

 

[timvrakas]

I don't understand what you're saying, the computer only updates the fan speeds every second or two (possibly only whenever needed, on an interrupt basis.) the Arduino actually monitors the RPM and PWM, the computer only sends percentage every 3,600,000,000,000 cycles

 

[chaosdesigns]

You can get a fan controller that has temperature sensors and responds to them. There is no need to involve the Operating System. For example; what happens to the fan speed control when the OS crashes? There would have to be a hardware circuit that forced the fans to spin up to full speed similar to the original G5 design.

 

[timvrakas]

Well if it were to "crash" (never happens to me) then the arduino would maintain the current speed and if the computer was not shut off soon (or if case temps went up) ramp up the fans.

 

[chaosdesigns]

You might find this interesting. http://www.tonymacx86.com/powermac-g5/92026-please-stfu.html

chaos

 

[timvrakas]

thx that was a good link i hadn't seen yet. dont know about the "not PWM fans" bit. i dissected one of the 80mm ones and it was clearly labeled 12v+ GND PWM TACH on the circuit board inside. just wired up the PWM Wire to an Arduino analog pin out (PWM) and gave it a standard Arduino signal. read the TACH perfectly on my o'scope. I will begin prototyping today

 

[timvrakas]

Also, I have some questions for the preference of the moders here:

Would you rather have the connectors pre-soldered (to standard length) or have you solder them to custom length?

What conector do you want me to have it draw power from? Molex, SATA, Or Floppy (the tiny 4-pin one)