How do you guys/gals auto-off your LCD screen?

**zac_haryy** · 02-20-2006, 11:46 PM

Well I am underway in the process of installing my carputer. I have bought a Lilliput 619GL-70NP 7" touch screen. I know of the two auto-on mods for this.

1-The one where you solder the cap and resistor to the mobo of the LCD
2-Get into manufacture's setup and setup auto-on when VGA is detected

Well what I am doing is putting a laptop in my carputer setup and I will have the carputer (laptop) turn on when the ignition turns on. I will have hibermon (an application somebody on the board made that makes your laptop hibernate after X amount of seconds when DC power is disconnected) put my computer into hibernation after the power is cut to the computer. Well the reason that I am using that is because I would like to leave the comp on for a min after I shut off the vehicle so that if I can mess with the carputer while vehicle is shutoff. So here is my dilemma. Once I shut off the vehicle and then lets say that I have option 2 setup on the Lilliput (auto-on when VGA signal detected) the screen will stay on but then once the computer actually goes into hibernation the screen will just sit there powered on. Since the Lilliput detected the VGA signal it turned on and then once the carputer goes to sleep it won’t detect the VGA signal but from what people have told me the Lilliput does not turn off when VGA isn't detected.

So how do I make my screen shut off after I shutoff my vehicle? I could put a relay from the ignition and make the relay turn on and off the screen when I turn on/off the vehicle but I want to keep the Lilliput running after i shut off the vehicle. So what do I do? Also when the Lilliput is off there is a red light that comes from it showing that there is power coming to it. Would this suck down the battery after a couple weeks with no use of the vehicle, or is it just simply a little LED being powered? Any help would be great and please let me know if you are confused by this because it is kind of hard to explain. Thanks!

-haryy

**xdjxklusivex** · 02-21-2006, 04:18 AM

errr not sure if this would work but.. on the laptop if u took a signal wire from a led or something that turns on when the laptop is on u may be able to run it through a relay to flick on when it gets a signal from there and flick off when the signal is gone... so the screen will be on when laptop is on an off when laptop is off

**zac_haryy** · 02-21-2006, 09:47 AM

Well I just came up with an idea that may or may not work. Basically what I am thinking is that when the PC powers up it should put voltage to the USB ports right away, correct? So then I could hook up a relay to the USB ports (the 5 volt output of it) and then have the relay switch on to power on everything that I needed. Let me know if this would work. Thanks!

-haryy

**dmcdlrn** · 02-21-2006, 09:57 AM

ya, that usb will work... but I recomend ps2 port... the usb often gets left power for a few seconds, and mine sometimes wouldn't shut off... so the computer would shut completely down, but the screen and amps and everything would stay on... not good... I switched to the ps2 port.. problem solved.

**zac_haryy** · 02-21-2006, 12:01 PM

So would I need to get a 5v relay then since the ps2 and USB have a 5v power source? Where do I get a 5v relay? Would radioshack have them?

-haryy

**dmcdlrn** · 02-21-2006, 12:27 PM

biggest concern is current draw... you don't want to draw much current, especially for the usb cause most of us use our usb for alot of things and not only is each device limited to 100ma I think, you only have a finite amount the bus will put out...

I used a reed relay... they are capable of a large range of voltage... I then used that to switch a larger automotive relay capable of handling much higher current draw. Now, understand that I used this all summer, but when it got towards winter before I parked my car... it had an issue where when it was really cold it would switch on, then back off then on then off... I never figured it out... so I think it was how I had the two relays wired together.... keep that in mind.. or find a more powerful reed relay...

**zac_haryy** · 02-21-2006, 12:38 PM

Well basically what I am thinking about doing now is taking that 5v wire from the ps2 port and then have the go to a resistor and then to a capacitor then to the relay. The relay would switch on whatever I wanted it to. I have two devices that I would like to use this setup for. These are it:

1 - To turn the inverter on/off that will power the external hdd
2 - To turn on/off the Lilliput touchscreen

So from the PS2 port I would take that 5v power and I would splice it so there there are two leads of power comping from it. Then I will have two seperate circuits setup up, one to turn on/off the inverter, two to turn on/off the screen. So the only time that the two circuits will draw power is when it is charging the cap and then once the cap it charged it will stop drawing power. Correct me if I am wrong. Let me know. Thanks!

-haryy

**dmcdlrn** · 02-21-2006, 02:56 PM

Well I'm not much of an electricity guy... I understand very basic concepts but have never looked much farther into it then that. If you put it so that power flows into the cap then the other leg flows out to the relay, then the relay will be close for a few seconds (depending on the size of the cap) then it will open again. If you had it in parallel with the relay it would provide stiffening or a few seconds of power after the computer shuts down.

Why do you want the cap?

**zac_haryy** · 02-21-2006, 03:34 PM

The reason for the cap is so that right when power is applyied to it then it will let power through the cap triggering the relay and then once the cap is full it will cut power to the relay making it un-coil the relay. I just need the relay to give a pulse on the other side of it. Basically simulating a push of a power button.

-haryy