Thread: HVAC Control on Car PC through Serial Port.

Here you go...

This is according to your spec I hope.

You just need to sort out your own wiring according to the chips you want to use.

...a single 12C508 would sort it all out.

Originally Posted by Chris31

You know, I really expected you to susse out what I was talking about...considering you been designing a far more complicated hw that this.

OK, Ill draw it for ya but I still need to add post to this thread, how am I supposed to show you what I drawn on paper

hehehe i was just seeing this from a different way .. more like software based ...

a servo signal line requires a pluse to work

0.6m Sec -45 degrees minimum pulse length
1.5m Sec 0 degrees center position
2.4 mSec -45 degrees maximum pulse length

so why cant we just add make vb send the pluse through LPT port ..?

This way we can control the pluse and servo angle...

Would love to see your hardware design also ...

Mastero

PS : It always takes more than one person to create something.

Originally Posted by Mastero

so why cant we just add make vb send the pluse through LPT port ..?

I dont think you be able to provide a reliable timmings through parallel port in windows. I may be wrong...it should work in DOS though.

Have a try, wont hurt anyway.

Just that bit banging in windows is never my thing.

Originally Posted by Chris31

I dont think you be able to provide a reliable timmings through parallel port in windows. I may be wrong...it should work in DOS though.

Have a try, wont hurt anyway.

Just that bit banging in windows is never my thing.

I know its unreliable ... just a taught ...

I dont think it will work ... VB timer does not allow 1.5

Ok back to the drawing board....

Mastero

Chris is there a way to read the code from a CP PIC .....??

Mastero

Originally Posted by antimatter

The hard part for me would be controlling the servo with the PC. It would take software and hardware working together. I have no experience with this. It would be nice to have HVAC controled by the PC but thats not what this thread is about.

If you are interested in doing it, there's really not much to it. For $25 you can get a USB Servo controller that can be controlled using Visual Basic (or VB Script for that matter) with a few lines of code.

Phidget Servo Controller

In addition, the board handles all the processing so you wouldn't be sucking up valuable CPU cycles with timers and what not. Also, I realize this thread isn't about a complete HVAC system, so I won't say anything else about it. Just wanted you to know it isn't to hard to do if you were so inclined.

Originally Posted by Mastero

Chris is there a way to read the code from a CP PIC .....??

Mastero

Used to do it on old 16C84. I doubt it very much if you can do it with the new chips.

Its been read protected for a reason.

Originally Posted by Chris31

Used to do it on old 16C84. I doubt it very much if you can do it with the new chips.

Its been read protected for a reason.

I know its for a reason.. the chip i am looking at is 16F72 is there a way for it ...?

Mastero

Ok the final software is ready ...... hardware is also ready but only the TYPE_1 (Still has errors) shall post pic soon.

Download the software's (YES two types with servo and without ) HERE

Please post your comment on the software.

Cheers

Mastero