ease of use?

Quote:

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Originally Posted by scott_fx

ok... so here is what i'll be controlling:
http://onfinite.com/libraries/1204489/5d3.jpg

what would my parts list be?
would i need relay for each button?
from this post:
http://www.mp3car.com/vbulletin/1037020-post17.html

it seems that i wont need the relays because the board will be mounted near the a/c controls


edit: damn it i didnt even read the product description.... 12 on/off outputs... so i should be set

the part that confuses me is what i'll need for the rotary encoders, i understood about the 4 wires and what not. but i'm not sure if that is digital or not and since i have two rotary encoders...do i need to purchase two boards?

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Well, perhaps.

The on/off outputs are constant 12 volts, switched ground. So, if those switches don't switch 5 volts, or if they are switched positive, you need relays.

Also, those rotary knobs could be variable resistors or could be rotary encoders. If they are variable resistors, that's great, you can use a digital potentiometer. If they are rotary encoders, that's a lot more complicated to simulate.

http://en.wikipedia.org/wiki/Rotary_encoder

http://en.wikipedia.org/wiki/Potentiometer

instead of relays could i use resistors to step down the voltage from 12 to 5v?

I'll have to wait till i get my car back before i can take it apart to see what is behind the knobs. If worst comes to worst i can just extend the rotary encoders (if that's what they are) and the vfd display off the board and mount them in my dash while using the pc to replace the buttons.

Quote:

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Originally Posted by scott_fx

instead of relays could i use resistors to step down the voltage from 12 to 5v?

I'll have to wait till i get my car back before i can take it apart to see what is behind the knobs. If worst comes to worst i can just extend the rotary encoders (if that's what they are) and the vfd display off the board and mount them in my dash while using the pc to replace the buttons.

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You can, yes, but you have to have a pretty good idea of what you're doing, and you'd have to understand what those buttons are doing, also. I can't really tell you how to hook it up without having it in from of me to test and understand how it works. I can say without a doubt that disconnecting the switches and connecting the relays will work.

relays it is then :-)

Here's a little more background on the issue.

We use NPN transistor arrays to drive the 12 outputs. NPN, by definition, switches the ground. We really had to do it this way to make it easy to drive relays. It's kind of difficult to explain, but I can draw up some diagrams if you like.

The contacts in the relay will work just like the contacts in those switches.

i think i am grasping it now, thanks.

http://www.laurentkneip.de/H_bridges..._direction.jpg


That is our configuration, and you attach a relay to those two terminals.

This works great because it makes relays simple to hook up, since 12v is part of the circuit.

However, you need to switch the EXISTING voltage, not insert 12v. Relays are great for that.

hey guys, thanks for all the input, i think i'm going to have to pass on this for now. I think it'll just be a bit too far over my head especially with the display and rotary temp knobs.

hopefully in the future i'll find a use for this device and will be able to implement it in my install. I think this is an amazing product and would love to support you guys.

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Originally Posted by greenman100

You can, yes, but you have to have a pretty good idea of what you're doing, and you'd have to understand what those buttons are doing, also. I can't really tell you how to hook it up without having it in from of me to test and understand how it works. I can say without a doubt that disconnecting the switches and connecting the relays will work.

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yes, i think we have to have a pretty good idea of what you're doing.thanks!:dance:

I want to do something simular with the hvac controls, but I don't want to use anything from the old controls. All the knobs are variable resistors, and you stated those can be controled by the brain right?
Attached is the pin outs for the controls I was thinking of replacing with the fusion brain. Thanks for any help you can give me, and thanks for the great product. I hope to be using it soon in my carpc install.
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Red Baron