2000 MX5/Miata EEEPC CarPC (Photos) - Page 6

enigmacarpc · 10-07-2008, 03:27 PM

I have a question regarding the RJ45 Loop back connector.

1. I have the carnetix p1900 this has a shutdown/start up controller already can I use this as the 12 volt source?

enigmacarpc · 10-07-2008, 03:34 PM

2. can this be done with 1 relay?

ibfragalot · 10-07-2008, 06:45 PM

no idea about the startup/shutdown controllers sorry mate. those are for PC's, I'm doing a laptop...

your not asking about using RJ45 as 12v source are you? just in case you are, definitely no!

little more than a volt going thru it.

enigmacarpc · 10-07-2008, 10:21 PM

No I'm not using the RJ45 as a power source that would cause a fire.

This is also for a laptop.

What I meant was on the diagram there is a 12V source I would use my DC-DC power supply as the 12V source this would take care of the start up power and this would also remove the power to allow shut down without car battery drain.

In the diagram this would go to the 86 side of the relay,I know the 85 side is ground.

Are the other 2 sides the 2 parts of the loop back cable?

ibfragalot · 10-07-2008, 11:19 PM

Thats correct. I used 1 relay for switching power to my box (fans, notebook power supply) and another relay to connect the loopback connections together.

Do note however, the loopback cable has'nt proved reliable. I gave up myself. It will work sometimes and not others. If you would like to go ahead with it, check the last page, some of the guys there made some advances though I'm not sure its proven yet. I finally just opened up my EEEPC and wired directly to the on button :P

ibfragalot · 10-07-2008, 11:21 PM

note - you'll also need to check the diagram of the actual wires to use on the RJ45 cable if you have'nt already, theres a picture floating around on this board. basically you link two together permanently, and another two are joined when you want the pc to turn on (these go thru the relay)

enigmacarpc · 10-09-2008, 10:06 PM

What did you connect the power on button to?

And do you have a cable coming out of the laptop case?

ibfragalot · 10-12-2008, 07:05 PM

I connected the power button to an external button in the car. When I get a chance I'll hook it up to a relay, where the RJ45 used to hook up, so that it will turn on with the car automatically.

There is a small disconnectable cable coming out of the kensington lock hole on the side of the laptop.

enigmacarpc · 10-14-2008, 01:33 AM

Thanks great idea.

Are there just 2 wires for the power you need to splice?

ibfragalot · 10-14-2008, 07:52 AM

Most laptop power buttons will use the standard little clicky button inside, which has 3 poles

_O_
| | |

You _really should use a multimeter to test_ but you will likely find the first and last are the ones to connect together to get a turn on. Test by pressing your multimeter against the first and last |'s, and when you press the button you will get a response on the multimeter. This means you've got the right wires.

NOTE: Its more complicated when connecting to a relay. Of course, when you press the on button on your laptop, or the on button you might put (temporarily like me) inside your car, you only press it for a second then release - you don't hold the damn button down while your driving!

So of course, when connecting to a relay you need to make the relay only connect the |'s for a second or so and then release to get a turn on. There are circuits at the12volt.com which show you how to do this (a few extra components, cheap as) and you should do this, otherwise if you just connect it straight up as per previous relay diagram, you'd effectively be holding down the power button continuously which would render unknown results.

So yeah, when you hook up to the relay schematic, check out the12volt.com for the diagram on where to hook up some extra bits so it only connects for half a second, then your done.. its called a momentary switch i believe.

Or you can be cheap and quick like me for the time being and just wire it straight to the 1st and 3rd |'s, to a press switch and bam its all good. But yeah, bummer having to manually press it everytime you start your car.

Also - I was thinking of keeping this button in some fashion so that I can reboot/shutdown the laptop if necessary - ie. windows crashing or something.

sorry for the long post, but i kinda like to explain even simple things in detail heh

wazza · 10-20-2008, 07:34 AM

nice job check out my setup www.carpcaustralia.com.au

cheers
wazzapc

lacning74 · 11-14-2008, 12:17 AM

Quote: Originally Posted by ibfragalot

Most laptop power buttons will use the standard little clicky button inside, which has 3 poles

_O_
| | |

You _really should use a multimeter to test_ but you will likely find the first and last are the ones to connect together to get a turn on. Test by pressing your multimeter against the first and last |'s, and when you press the button you will get a response on the multimeter. This means you've got the right wires.

NOTE: Its more complicated when connecting to a relay. Of course, when you press the on button on your laptop, or the on button you might put (temporarily like me) inside your car, you only press it for a second then release - you don't hold the damn button down while your driving!

So of course, when connecting to a relay you need to make the relay only connect the |'s for a second or so and then release to get a turn on. There are circuits at the12volt.com which show you how to do this (a few extra components, cheap as) and you should do this, otherwise if you just connect it straight up as per previous relay diagram, you'd effectively be holding down the power button continuously which would render unknown results.

So yeah, when you hook up to the relay schematic, check out the12volt.com for the diagram on where to hook up some extra bits so it only connects for half a second, then your done.. its called a momentary switch i believe.

Or you can be cheap and quick like me for the time being and just wire it straight to the 1st and 3rd |'s, to a press switch and bam its all good. But yeah, bummer having to manually press it everytime you start your car.

Also - I was thinking of keeping this button in some fashion so that I can reboot/shutdown the laptop if necessary - ie. windows crashing or something.

sorry for the long post, but i kinda like to explain even simple things in detail heh

did you see this auto-on laptop momentary switch module that does exactly what you are saying? i'm installing a eee 1000h based carpc and i'm scared to learn how to solder.

ibfragalot · 11-19-2008, 06:24 AM

Quote: Originally Posted by lacning74

did you see this auto-on laptop momentary switch module that does exactly what you are saying? i'm installing a eee 1000h based carpc and i'm scared to learn how to solder.

no i did'nt, thanks, thats it exactly.

hey - dont be afraid about soldering. its nothing. i first soldered when i was a kid - only thing you have to be scared of is burnin your finger(thru general stupidity), and i still do that now on occasion lol

lees40 · 12-01-2008, 02:25 PM

Quote: Originally Posted by ibfragalot

no idea about the startup/shutdown controllers sorry mate. those are for PC's, I'm doing a laptop...

your not asking about using RJ45 as 12v source are you? just in case you are, definitely no!

little more than a volt going thru it.

Why not get a cheap router, and use the "wake on lan" function to bring the laptop out of hibernation when you start the car? Got the idea from this guy:

http://www.avbrand.com/projects/carpc/installation/

I'm doing the same thing with my install, which also uses a laptop. Can't swear to you how well it works yet, I'm putting the inverter in this weekend, which will be connected directly to the battery via a relay that will only provide it with power when the car is running. Then the laptop, router, and powered usb will be connected to the inverter to all power up when I start my truck. In theory, and according to the fellow I got the idea from, it should work great.

lacning74 · 12-01-2008, 04:07 PM

Quote: Originally Posted by lees40

Why not get a cheap router, and use the "wake on lan" function to bring the laptop out of hibernation when you start the car? Got the idea from this guy:

http://www.avbrand.com/projects/carpc/installation/

I'm doing the same thing with my install, which also uses a laptop. Can't swear to you how well it works yet, I'm putting the inverter in this weekend, which will be connected directly to the battery via a relay that will only provide it with power when the car is running. Then the laptop, router, and powered usb will be connected to the inverter to all power up when I start my truck. In theory, and according to the fellow I got the idea from, it should work great.

While it has worked for others, I had issues trying wake on lan. My eee pc 1000h supports it but it only works if the computer was shut down while plugged in and remains plugged in with power until you wake it up. I only supply power when the car is running via my car adapter, so after my computer loses AC power, the computer will not wake up via wake on lan.

Other users here have had the same problem with the eee pc as well. I also remember a guy with a Compaq laptop that had the problem I think. I wish my BIOS had a start-up when power detected option. That would make our lives easier.

I ended up soldering my power switch and I'm going to attach a 528T pulse timer relay to activate it.

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