Questions about HP laptops - Page 2

turbocad6 · 10-10-2006, 10:43 AM

if you want help figuring out how to wire it up, I did a thread about running a laptop off an opus... similar enough that that should get you straight....

you will need to provide a "on" signal from the laptop... this can easily be acomplished through a 5v relay off the usb... click my id, then user profile, then all threads started by turbocad6.... you'll see it there

v8 scimitar · 10-10-2006, 11:15 AM

XP for sure without a doubt as it starts quicker already out the box.

As for laptop I have one question. Does it have a DVD drive as standard? If the answer is yes then rafster might be right if the answer is no I still say your going to struggle with it. Reason being is that if it came with a DVD drive then it more than likely has an mpeg decoder on board. If it didn't then I would put money on it not having a decoder so it will all have to be done with software which will kill the performance. It might play fine but your not going to be able to do anything else at the same time.
You have the laptop so spend a few hours loading it up with whatever you want to use and see for your self. After that you will know for sure and its only cost you time.

miwise · 10-10-2006, 11:47 AM

I know it has an ati video card chipset. I'll have to look at it again. I'm going to try the laptop thing first. If it don't work I can always go with plan b, the athlon xp. Thanks for the insight to both of you!

Vineet Singh · 10-10-2006, 12:14 PM

I have 2 HP laptops, both have ATI mobility video cards, which are decent for carpc's.

One is a 750mhz, the other is 1ghz. Both work fine for car use, but not with some of the latest flash skins for roadrunner. I'm in the middle of upgrading mine to a dell P4 3ghz, running at 1.6ghz to stay cool. It has a geforce go 5200 32mb video card.

Tiny XP is a great idea, I'm not sure it supports laptops, but you really have to play with it to see what you can do with the 500mhz. I know it can do DVD's, but it's not good at multitasking. GPS is fine, so is MP3 playback. Heck, my first car computer was a 233 pentium 1 MMX

back in 1997 or so. There is also a tiny windows 2003 distribution called Windows_2003_eXPerience_Edition, (use google) but it uses windows server 2003, stripped of a lot of things. Very stable, very little ram usage! Avoid antivirus software on your carpc unless you intend to have internet access somehow.

To power on, find the control board under the switch (sometimes seperate, will make it easier). Find which two pins of the switch get shorted when you press the button, using a digital voltmeter (in resistance mode). Extend two wires from these, and bring them out of the laptop. Touch them together with the battery in, and see if it turns on. It usually takes 3-4 seconds of holding the wires or switch to turn it off... which is usually less time than the engine takes to crank!

See where I'm going with this? Use the starter relay to activate a seperate relay (bosch 12v). This relay has 4 or 5 pins, sorry no diagram here. One of the two opposing pins will be the starter signal (+12), the other will be ground to the car chassis. They probably have numbers like 87, 86, etc, look for the standard pinout and functions.

The other two pins, will be hooked to the two wires you brought out of your laptop. When the starter is energized, the relay is clicked on, it turns your laptop on! Now if you KEEP starting your car (if your car needs a tuneup or is really old and crapurated like my z), this will not work right.

Then simply set windows power management to shut down, or hibernate, if running on internal batteries after 1 minute. (Don't choose standby, it will drain the laptop battery in 5-10 hours). If you have usb devices, make sure that windows will force them to shutdown, in powermanagement tabs under device manager, but this is not usually a problem.

Of course you would need a laptop air/auto adapter, but they are usually easy to find. Don't use a 12v to 110vac adapter to your regular laptop adapter that goes from 110v back to 16-19v on most laptops, unless you have no other choice (like the dell inspirons that use the PA-10 or higher adapters). Targus makes some good 60w, 75w and 90w adapters, which is enough for all P3 based and centrino based laptops afaik. P4 and Athlon may use more than 90w, and not work right.

The air/auto adapter should be hooked up to a 12v source that is on, ONLY when the key is in the ignition and turned on to accessory.

There is some wiring to do, and a few cheap components, but if you plan it out, you will see it's not that hard.

turbocad6 · 10-10-2006, 01:56 PM

the problem with your design is, if you shut the car off & then restart it right away, your laptop will turn off... anytime your laptop is already on, it will turn off again with cranking.... a controller monitors the state of the pc, & is much more inteligent... if you want a simpler startup for your laptop & want to rely on windows to shut it down, look for webmasters startup controller.... it's simple & basic, but at least it is much better than just a relay from the starter... either that, or there are circuits you can build yourself too..., but a bit more control than just a relay...

Vineet Singh · 10-10-2006, 02:09 PM

Why would it shut off if it's in windows, and you have set the powermanagement to not do anything when the power switch is pushed? I can see if it hasn't gotten to windows yet...

You could also splice the wires going to the relay, to a hidden pushbutton switch for the unforseen, like when you just want the pc to be on, but w/o the engine running.

EDIT: The screen I'm talking about in XP is under power options, 4rth tab (Advanced). Where it says "When I press the power button on my computer:" you pick "Do nothing"

Also, on both my HP laptops, the dedicated suspend button also functions to turn it on, and you can do the same thing if it's easier to get to, just pick the corresponding dropdown box in the same menu. Or you can run 2 sets of wires out, power to the dedicated, hidden or not, power button near your dash, and one set (suspend) to the starter relay contraption. This way you can get out of bluescreens or crashes.

miwise · 10-10-2006, 04:35 PM

Well, that sounds like it would work, but I didn't really want to get that involved with relays and such. I think i'm going to try the power supply option, but first I'm going to need to get the supplies to get the laptops working correctly. I'll probably buy the Carnetix 1900 dc-dc regulator from mp3car.com for only 100 dollars. If I can find an opus or something like it on ebay for a better price, I'll probably go with that. My factory radio has a nice volume attenuator with push button control. I can use it for the power and volume control (hopefully) with my computer system.

Now onto the lexusownersclub forum to see if my factory amps (pioneer subwoofer and speaker amps) will accept low level inputs (if not, I'm looking at even more to buy).

Vineet Singh · 10-10-2006, 11:50 PM

It's really only ONE $5 relay, maybe $10 if you want to get ripped off for it.

Then get this 70w or the higher 120w Kensington power adapter (DC DC) for 69.99 from circuit city. Ebay has cheaper similar items, but avoid the ones that look like this (failed after 1 year on me, high pitched squealing)

Kensington 70W DC Power Adapter (38006)
It's really slim, doesn't get hot, and has a 1 year warranty.

And if you want powered USB hubs, or need to power an external sound card, get this splitter for the same adapter (one end goes to your laptop, the other to your lower voltage device).

Kensington Dual Charging Cable (38013)
$20

The Carnetix seems like a good idea if you want to fiddle with stuff, but being a laptop, it doesn't need half the features the carnetix has. If you were doing an ITX or MATX motherboard, that would be the way to go. The built-in laptop battery will cover any crank or power fluctuation issues.

It's also out of stock

No "correct" way of doing the car pc, but this advice is from my personal experience, and I've used a controller before.

miwise · 10-11-2006, 05:29 PM

Next thing is to see if I can find a hard drive chassis for my laptop as its missing (bought it a while back with no hard drive). Can't use it without it unless there's another way to boot it up without the ide port. Does anyone know a place that could do custom work on the lcd panel? Somewhere that I could send it and my head unit to so that they can trim the edges off the panel so it fits like my head unit did. The head unit's kind of in the shape of a trapezoid, no straight sides. I tried a place that does laser cutting, but they only did big items. Nothing as small as a monitor. Thanks!

miwise · 10-11-2006, 07:37 PM

Nevermind. I'm scrapping the old hp's and going to use a different laptop. Just bought it off ebay. Now gotta buy the power supply, but that can wait until I get the laptop and everything working. Excited: 1ghz amd duron w/dvd/cdrw/etc/20gb hd/pcmcia for firewire and my ipod. Now gotta find a good monitor I can have trimmed up to fit my dashboard.

Vineet Singh · 10-11-2006, 08:20 PM

Nice, what kind of car though? Usually you have to trim up your monitor casing yourself (and mold it to a trim piece of your car, or make your own trim piece).

miwise · 10-11-2006, 08:40 PM

I've got a Lexus SC400. I can't really mold it to anything b/c of the way the factory unit was built. I'll have to trim off about 6mm from the top tapered to about 12mm from the bottom. My opening's not perfectly square. If I just trim it, I think it should be perfectly fit. I have an inlaw who works at a machine shop. I'm going to see if he can do anything with it after I get it. I want it close to perfect. I'm in the process of getting the monitor now, a 7" touchscreen by eonon. Looks like it should work almost perfectly for what I need other than the slight shaving that must be done. I'll shave it then paint it satin black hopefully to match the dash and climate control unit.

miwise · 10-11-2006, 08:42 PM

BTW, got the laptop w/ 512 memory, bag, and other items for 125 shipped. only thing wrong with it is the backlight on the LCD is broken, so the screen is supposedly hard to read, but who cares about that.

Vineet Singh · 10-11-2006, 10:57 PM

Does it look like this?

My friend has the v8 SC also, he wanted one, but he's sorta cheap. I was remarking how easy it would be to do in his car vs my wife's titan, or worse, my friends oval focus lol. Nice car!

Got a friend that is a teacher at the lexus technical center, if you mess something up, I can probably get the part

. I would buy a spare radio trim, unless it's really part of the radio (

) and work with that.

We also do some work for avery-dennison (make 60%+ of car interior accents), and might be able to get a 1x1' sample sheet of the burled fakewood overlay, if you can't find it on your own.

miwise · 10-12-2006, 06:37 AM

Yep. Just like that. Same color too. The trim's not part of the radio, but it wouldn't look right if it were fabbed into the trim. The screen I bought is only a few mm too large, so I'm going to see what I can do from there. I was also toying with the idea of a recessed screen to keep the glare off, but I would have to get someone to do the fiberglass work (I already have someone in mind for that. . .the person who did some work on my boat, he does a lot of fiberglass work). The recessed screen would have to be totally custom b/c of the odd sized radio. . .trapezoidal 2.5 din. . .7.25 to 7" wide x 5" tall. Big enough for the screen, but strangly shaped. What would the overlay do for me?