SparkFun Forums

[mr. manka]

Hello everybody.

Recently I have embarked into a new realm. Electronics.
Now here uis my situation. I am currentlybuilding a Vapor Phase change system, to cool my CPU. I am trying to build a Controller that will...
!. Monitor the CPU temp, Via Thermocouple.
2. Monitor and regulate fan speeds, Via PWM.
3. Start up and Shut down the Computer at a set temperature.
4. Interface it Via the serial or LPT port.
5. Display the information on a graphic LCD, (T6963C to be exact)

I have decent soldering skills, and can follow directions to a T.
I am just not that good at the whole engineering part.

Any help will be greatly appreciated.

[busonerd]

Can you program? thats going to be the biggest hurdle.

I would suggest an AVR.

1. The thermocouple part is easy - Sparkfun carries some thermocouple amps - they have a nice digital one IIRC.

2. Fan speed + PWM, again, easy with the right avr, and if the fan takes a pwm speed control, you're set. If you're actually doing power PWM on the control lines, you'll need a a fet to do that for ya.

3. I'm not sure how you want that to be done... just tripping the "power on" contacts?

4. Serial = use a max232 to connect to the avr serial port. Easy.

5. From a quick google, should be fairly easy with an AVR.

From your description - the HW side is fairly simple. The FW side is not gonna be.

--David Carne

[mr. manka]

No, I cannot Program, BUT I will learn to, as I am a rapid learner and am dedicated to this project.

Could you suggest a few tutorials to sharpen my skills.

Also, I would like one power supply for the whole thing, preferrable in AC, as I plan on running it off the mains from the compressor. And it would be much easier to just step down the AC from 120 to what ever.

I would like to power the fans off of the controller, most likely 3 of them, no more than 1.5A, I realize that i will have to use a rectifier, but that is no big deal.
As to the power on/off situation, I would like to turn on the Unit/ controller, and then one a certain temp is hit, say -25C, the PC will turn on. also, If the CPU hit the critical temp, say 0C, the controller will shut down the PC,and the Unit.


Also y do I need a Amp for the thermocouple, shouldnt i just Use an ADC


EDIT, I do have some programming experience using a proram called python..

[n1ist]

I used the Maxim MAX6661 fan controller in a recent project. It reads
the temperature (of the chip and of a remote diode junction) and can use that to automatically control the fan speed (PWM), or you can read the temperature and set the speed yourself. It also has 2 hi-temp alarms and can detect a stuck or slow fan. You talk to it via SPI.

/mike

[mr. manka]

thanks for the help with the fan controller,

I was wondering about the display?

How would i attach it to the controller, and how would i code, in AVR, it to display what i need.

thnakls for all of the help.


P.s. a list of what to buy, would be greatly appreciated.

[busonerd]

an ADC usuallly will not provide the required sensitivity.

--David Carne

[mr. manka]

ok, I have decided to go with a ATMEl ATmega32 controller, becasue I can fit in the number of thermocouples, as well as the fans.

just a few more questions, can I hook the LCD directly up to this.
and do i need an ADC amp for every thermocouple?


thanks.

[mr. manka]

ok, I found the schematic for how to hook up the LCD here http://www.8052.com/codelib.phtml and there are also snippets of code Using this display driver. which should make it easier for me to program, right?