Intermittent touchscreen problem :-(

sigol · 10-30-2005, 08:16 AM

Hi hope somebody can help...

My project is virtually finished. Will post final pics soon.

I've got a liliput 7" touch screen and the problem is that the touchscreen facility is intermittent. I can hear the sound Windows makes when it loses or finds a USB device.

There seems to be no pattern to this. It can happen at startup, not happen all day or happen just about whenever it feels like it. When Windows loses the connection, it can be down for seconds or for hours.

The connections seem nice and snug. The only thing I can think of is that the USB cable goes in to a USB hub in the glove box so i can't rule out whether the hub is faulty or the screen. (However, when the screen goes down, the backup mouse and keyboard work fine - so probably not the hub then).

Please can you help - it's putting a dampner on an otherwise great install. :-(

Thanks in advance...

DaKyy · 11-01-2005, 08:41 AM

I've got the same problem, this has occured after I installed the carpc permanently to my car. Before I had the case just bumping around the trunk and it worked OK. It usually starts to work when I shut down Lilliput and reconnect the monitor cable (usb&vga). Don't have a solution though.

CapitaineFritz · 11-01-2005, 09:07 AM

You can try:

1- Without your usb hub... just to be sure
2- Another computer (like a laptop), again just to be sure it's not the O/S

IntellaWorks · 11-01-2005, 09:31 AM

Whats the temp. Inside your car when its doing this problem?

sigol · 11-01-2005, 01:48 PM

Guys, thanks for your replies.

DaKyy: I know! it's frustrating. I had the PC in bits for a month to prove it all works and the minute I install it - this! arrghhh!

CapitaineFritz: Will do - good idea about laptop - I will try and report back.

IntellaWorks: I don't have the luxury of being in a nice warm country like you. I live in Manchester where it rains more than in any other city in Europe! It's a constant 19 deg C in my car and no more! It can happen at any time of day and under any environmental conditions.

Best wishes,

Sigol.

volum3rider · 11-01-2005, 03:41 PM

hmm this happened to me before and the reason for me was that my usb hub was not getting enough power. You can try to power the hub it it isnt already becasue a bus powered hub only gives out 100ma a port where as a powered hub gives out 500ma a port. The touchscreen draws 100 ma so my screen would stop working once in a while also. Hope that helped.

sigol · 11-02-2005, 01:16 AM

Hi colum3rider,

Yes that certainly could be the problem. The hub is bus powered. I'll try powering it and see what happens.

Cheers!

DaKyy · 11-02-2005, 12:53 PM

I've tried plugging every other device out but still having the same problem...

DaKyy · 11-05-2005, 11:36 AM

I tried to switch the touchscreen to another USB-port, and only kept the TS connected of my USB devices. Still the same problem occurs. It works for while and then it stops when I start the car next time. If I unplug the power cord from monitor and stick it back in, Windows seems to recognize it(you hear the sound) and instantly you hear the disconnect sound.

Next I'll try the TS drivers, and after that I'll probably verify that the USB-connection is OK from the monitor end. The cable from front to boot is good as the USB keyboard works ok when it is connected.

DaKyy · 11-08-2005, 12:06 PM

OK, the TS is fixed now - until the next time the problem appears

Probable cause is the cord from screen that is connected with that weird, tightening thingie

So, Sigol, Test your USB cable is ok, and after that try reconnecting the screen cable...

sct73 · 11-09-2005, 11:18 AM

Did you manage to figure out exactly what this problem was? I have had the same problem, driving around it can be fine for hours and then suddenly just start "boinging" the windows sound every now and again, this afternoon it did it and now the touchscreen wont recognise my touches. It recognizes the touches but not where I touch the screen and it doesnt move the cursor. Also I get the 'calibrate the screen' message everytime I boot up, which asks me to touch the four corners of the screen each time. Do you have any ideas??? I have one of these screens which wonderfully came with no drivers!! which was a problem to start with and I have installed the drivers from http://www.egalax.com.tw/eg/drivers.htm which have been recommended in other thread I have read. Do you have any ideas??

Thanks

Simon

ITL · 11-09-2005, 11:27 AM

if you're sure you've got enough power to the USB, it could be a bad USB cable...might be hard, but I'd try getting ahold of another cable just to verify. Not to mention first removing and THEN re-installing the driver.

DaKyy · 11-09-2005, 05:34 PM

Yeah, first, get a new/working USB-cable and place it temporarily in your car (yep, put it with the other 254 temporary cables) and test if it acts the same way. If it does act the same way, and for example, the TS USB disconnects (you hear that boing), plug out your TS USB cable, and reconnect it. If you don't hear the connect sound this time, it's probably somewhere in the cable.

My TS is still working, the problem seems to be the touchscreens own cable connector(vga&usb). That connector is awful desing.

I was also suspecting the installed USB-cable, that is ran under panels with other cables, including the main power cable for carpc. Inductance could play up with that kind of tricks. More so if there is poorly(poor quality) shielded cables.

irhiggs · 01-29-2008, 08:02 AM

This post is old, but helpful.

I had 2 active USB cables in serial. The power from the computer in the trunk was too low and the screen could not maintain a stable connection with the computer. I assume there's a USB device recognition period because it would work sometimes. I inserted a powered usb hub (without the power) and it solved the problem. I imagine this is because the USB hub can maintain a good connection with the computer by not requiring power to do so, so if the touch screen is flickering in and out of connection, this is smoothed by capacitors in the hub.

My second theory is that the screen likes the hub better than the active usb cables because the hub is sexier.

americasfuture2 · 02-12-2008, 10:05 AM

my lilliput was doing the same thing. it turns out the cable going to the monitor was being pulled on. hit a bumb and its disconnected, but still had video. i had to put some slack in my cable. havent had a problem since. (2 weeks now)