To those of you with your computer in your trunk

SkaLou · 02-26-2008, 12:56 PM

How do you get your USB to the front? I used a USB extension cable that runs to a hub in my glovebox, I ran all of my cables beside each other - power, audio, video, USB... I talked to a guy who installs car stereos professionally, he said power+audio isn't that big of a deal, so I figured this would be okay. The video does not have much interference, even when the car is running (but that little bit is because of the cheap VGA cable I used), the audio has really no distortion at all... but all of my USB devices are SLOW AS SIN. I have three suspicions - the first is attenuation - I've gone out of the range USB cables can handle - I will need to build a USB repeater; interference - much of the data is lost and needs to be resent, causing the slow speeds; and faulty USB device - one of my devices may be faulty, causing other devices to have problems.

What do you guys think? What should I do? Tonight I am going to try removing some devices that I suspect might be the faulty ones and see how it goes. Also plan to test said devices on a laptop short range. I will update then.

krnpimpsta · 02-26-2008, 01:47 PM

I run an extension cable to my hub. 13ft or so I believe. No issues.

Enforcer · 02-26-2008, 01:56 PM

check the hub is USB2.0 and not USB1.0

brucedog · 02-26-2008, 02:33 PM

My son ordered a 2 fer $10 USB 4-hub thingy, and it was horribly slow, too, so I would guess that yr hub is the trouble.

I ordered my 4-hub from mp3car store; may have been a bit overpriced, but all devices glide right along...and my cabling in station wagon is about 12'.

Best of blessings and luck.

SkaLou · 02-26-2008, 03:13 PM

I have a powered USB 2.0 Hub.
http://www.newegg.com/Product/Produc...82E16817111402

I do have power attached to it.

I do not believe the hub is the issue, however because I do not believe this I had not planned on testing it. I will try testing it when I run my other tests. Thanks!

Any other ideas?

The max length for USB is 15 feet (5M). I should check if I went over that slightly with the extension cable + hub cable.
EDIT: Nope, I used a 10 foot extension cable and I know that the other cable isn't close to 5 feet.

Bugbyte · 02-26-2008, 09:07 PM

Do the USB cables run near power wires? It could be cheap cables, but I've never heard of slow USB devices. Are you sure it isn't your computer?

Is there a way to test your setup out of the car with the same cables and hub to see if it remains slow?

ss0518 · 02-26-2008, 10:18 PM

I know this will sound odd but if you're having problems going distance with USB try running the USB over CAT5.

You can run almost anything off of CAT5. People have ran VGA, low power audio, s-video, among other stuff.

I have not tried it myself but as I develop my Car PC I plan to use it as much as possible since it is so cheap. You just need to make sure you use the proper pairs of wires to limit the EMI.

You can directly wire it on to the CAT5 or you can buy adapters that will convert it for you and get very good distances but cost an arm and a leg.

Here is a site that has information about wiring USB and S-Video over CAT5:
http://girasoli.org/?p=58

Here is a site that has information about wiring VGA over CAT5:
http://www.geocities.com/dougburbidge/vgaovercat5.html

If you do try this though, let me know how it worked out.

Hope this helps.

ptk · 02-26-2008, 10:18 PM

most likely you hub. not all hubs are build equar. I will stick to reputable hub. I had the same issue, running a 5m USB extension cable. I had initially used small cheap supposedly USB2 hub and had major problem esp. with USB DVDROm drive. eventually i ditched it for belkin hubs and things improved.

SkaLou · 02-26-2008, 10:41 PM

@bugbyte- I can't try the computer out of the car with the same cables, but it's a brand new PC that worked fine on the bench with other devices. If needed I can easily remove it from my trunk... it's velcro'd in.
As stated in my original post, all cables run together. I did use 8awg wire though, so it should have less noise than thinner wire would.

@ptk- Hmmm... D-Link hubs are generally pretty good... I will keep this in mind though.

Found this in the reviews.
"This isn't actually a fully powered USB hub. The USB spec specifies 500mA per device from powered hub. 500mA*7=3.5A. This thing comes with a 3A power brick. Since the hub uses some power, and power systems generally are about 70 percent efficient, that means you're probably getting 300mA per port. It'll power some things, but hook up 7 high power devices, and this thing won't work. Why do companies bother making products that don't work to spec?"

Hmmm, could be the issue. I do have all 7 ports in use, I am using a DVD drive as well. I will try and see how it works with less devices plugged in. Thankfully I have some unnecessary stuff plugged in that can go directly to the computer (like my bluetooth and wireless) and really only the screen touchpad and DVD drive need to be plugged in. Next post will include results of testing.

andrewanderson · 02-26-2008, 11:14 PM

I agee, relocate the wire before you go out and purchase a new hub.

If that doesn't work purchasing a new hub is the next logical step.

SkaLou · 02-26-2008, 11:39 PM

I just sat down in my car with my laptop and first tried unplugging what I thought the culprit devices were.

I bought two USB extension cables, about 3 feet each to go from my hub and be integrated in my dash... FROM THE DOLLAR STORE. Though they seemed fine when I used them on my computer, last night whilst having problems, they were reading a keyboard and mouse fine, but weren't handling my flash drive even... One of them did sometimes, the other didn't at all. Hmm I thought, probably bad cables.

But then after reading that power thing, I first tried something else. I previously had wireless, bluetooth, a DVD/CD-RW drive (no external power, draws power from hub), and my touchscreen all driven by this, plus I had my keyboard and mouse temporarily plugged in.

Alas! No more "unknown devices" randomly appearing and disappearing in Hardware Manager, no more USB devices cutting out on me, back up to full speed transfer on the USB (took about 5 minutes to copy all the data from my drivers CD to the hard drive).

So I plugged the bluetooth dongle into the computer directly, and am toying with what I want to do with the wireless. I didn't really want to mount it somewhere, I wanted to be able to move it around to get a better signal, which is why I had it in my glovebox to begin with.

Any ideas on that last part?

ANYWAY! So it seems the problem is solved! Thanks everyone for your help, I'd seriously be pulling my hair out right now if everyone hadn't suggested the hub was the issue and I'd gone to read those reviews on newegg.

Bugbyte · 02-27-2008, 09:00 AM

Glad to hear you figured it out. As for the bluetooth dongle, does it work where it is? If so, why do you need to move it around?

It it isn't working where it is, you could plug it into a short extension cable and move it to a location that is unobtrusive. I've seen receivers and GPS units placed near wheel wells under the plastic trim that worked quite well.

SkaLou · 02-27-2008, 12:24 PM

The bluetooth was in the glovebox, but if I leave it plugged in I can't plug high powered devices in my dash. So I just moved it directly to the computer in my trunk. Haven't tried connecting to it yet, I was working on other things last night, going to try using my phone as a dial up modem today with it.

brucedog · 02-27-2008, 02:37 PM

Yea,

I have my wireless kbd USB rcvr and bluetooth dongle plugged into carpc @ rear of station wagon - both work fine. They stick out a bit, so I have found that I must be careful not to whack 'em.

Dial up using phone and bluetooth dongle really isn't that slow, at least w/T-Mobile. But it's nice to have that Netgear wireless adapter for when others' networks permit connecting to hispeed...

JimmyFitz · 02-27-2008, 05:43 PM

Quote: Originally Posted by brucedog

Yea,

I have my wireless kbd USB rcvr and bluetooth dongle plugged into carpc @ rear of station wagon - both work fine. They stick out a bit, so I have found that I must be careful not to whack 'em....

Try these:
http://store.mp3car.com/FlexUSB_Adapter_p/cbl-050.htm
They will allow you to point the dongle straight up for better range while plugged into the pc and they will give if they are "whacked". I found them at ratshack and other local stores as well.