My LCD screen hack - Got it working! Check it out!
parts-man73
Posts: 830
Inspired by OBC's recent budget LCD screen hack. I decided to pull something out of my "future projects" box. I work at an Automotive Salvage yard and come across some pretty neat electronics. I had found a minivan one day with a entertainment system that featured a LCD screen that flipped down from the ceiling. I kept it, planning to some day interface it to a Propeller. The connector plugged into the vehicles main wiring harness, and did not have any regular video connectors. Just 5 wires to figure out. I grabbed my ohm meter and went to work.....
There is a 6 inch long wiring harness that connects from the vehicle harness, to the PCB on the back of the LCD screen. At this connector there is 8 wires. 2 go to a potentiometer(contrast or brightness control I assume) and 2 are connected together inside that 6" wiring harness. So we still have 5 basic wires to figure out.
I removed the metal shield from the back of the screen to get direct access to the PCB. I found the Ground plane of the PCB, and verified it was a ground plane by finding a datasheet for one of the IC's and verifying continuity between the VSS pin on the IC and this ground plane.
I tested the wires one by one for continuity with the Ground plane, and found 4 wires in the PCB plug that had continuity with VSS.
One wire(pink) I believe to be the voltage supply
There were 2 wires wrapped in foil, One of the wires that I figured out was tied to the ground plane of the circuit board was stripped, laid bare against the outside of the foil wrap, then wrapped in electrical tape. I am assuming these are the video signal wires.
One of these 2 wires is blue, and shows continuity to the ground plane on the PCB. Signal ground I am assuming here.
The other wire that was wrapped in foil is green. This wire measures around 75 ohms in respect to VSS. When I tested an RCA jack on a TV, There is around the same impedance between the center and shield of the video RCA input jacks. So this must be the Video signal.
With all the confidence in the world, I connected the pink wire to 12 volts, the ground wires to ground. The blue and green wires I connected to a composite video source. Green as tip and blue as shield. Powered it up, and.......
Nothing happened.
Any ideas why this isn't working? I do accept the possibility that the screen might be defective, as it was used, and I did not have the opportunity to test it while the van was still operational.
This would make a really nice screen!
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Brian
uController.com - home of SpinStudio - the modular Development system for the Propeller
PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!
SD card Adapter - mass storage for the masses Audio/Video adapter add composite video and sound to your Proto Board
Post Edited (parts-man73) : 2/10/2008 6:53:07 AM GMT
There is a 6 inch long wiring harness that connects from the vehicle harness, to the PCB on the back of the LCD screen. At this connector there is 8 wires. 2 go to a potentiometer(contrast or brightness control I assume) and 2 are connected together inside that 6" wiring harness. So we still have 5 basic wires to figure out.
I removed the metal shield from the back of the screen to get direct access to the PCB. I found the Ground plane of the PCB, and verified it was a ground plane by finding a datasheet for one of the IC's and verifying continuity between the VSS pin on the IC and this ground plane.
I tested the wires one by one for continuity with the Ground plane, and found 4 wires in the PCB plug that had continuity with VSS.
One wire(pink) I believe to be the voltage supply
There were 2 wires wrapped in foil, One of the wires that I figured out was tied to the ground plane of the circuit board was stripped, laid bare against the outside of the foil wrap, then wrapped in electrical tape. I am assuming these are the video signal wires.
One of these 2 wires is blue, and shows continuity to the ground plane on the PCB. Signal ground I am assuming here.
The other wire that was wrapped in foil is green. This wire measures around 75 ohms in respect to VSS. When I tested an RCA jack on a TV, There is around the same impedance between the center and shield of the video RCA input jacks. So this must be the Video signal.
With all the confidence in the world, I connected the pink wire to 12 volts, the ground wires to ground. The blue and green wires I connected to a composite video source. Green as tip and blue as shield. Powered it up, and.......
Nothing happened.
Any ideas why this isn't working? I do accept the possibility that the screen might be defective, as it was used, and I did not have the opportunity to test it while the van was still operational.
This would make a really nice screen!
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Brian
uController.com - home of SpinStudio - the modular Development system for the Propeller
PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!
SD card Adapter - mass storage for the masses Audio/Video adapter add composite video and sound to your Proto Board
Post Edited (parts-man73) : 2/10/2008 6:53:07 AM GMT
Comments
document.sharpsma.com/files/LQ064A5CG01_SP_041499.pdf
There's a "test" terminal, that when connected to GND regardless of the existance of an input signal, the backlight will light up.
When I jumper this terminal to ground, the backlight turns on! I see a flicker of an image when the backlight is on. I think I almost have this.
For any of you that might want to try to find one of these in a salvage yard near you. I got it out of a Ford Windstar. They were used in the 2001-2003 model years as a factory installed option. The plastic housing says "AutoVision" on it.
I'll keep you posted on my progress!
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Brian
uController.com - home of SpinStudio - the modular Development system for the Propeller
PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!
SD card Adapter - mass storage for the masses Audio/Video adapter add composite video and sound to your Proto Board
The plug on the PCB was not making good contact. It appears to be a factory defect. I doubt this thing worked anymore when it was in the vehicle! I soldered wires directly to the underside of the PCB right to the solder pins for the connector. Threw the wiring harness that came with it away. plugged it in and It works great now!
Hint - There's a couple of these on Ebay right now - search for "autovision" and you'll find them. They starting bid is only a penny and shipping is $10. They claim "The cable on these is bad so the lcd could be good but i have know way to test it." That's what tipped me off to check for loose solder connections. These make great little Propeller screens!
PM me if you need help getting one of these going if you happen to pick one up. If you're good with a soldering iron, it's an easy fix.
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Brian
uController.com - home of SpinStudio - the modular Development system for the Propeller
PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!
SD card Adapter - mass storage for the masses Audio/Video adapter add composite video and sound to your Proto Board
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E3 = Thought
http://folding.stanford.edu/·- Donating some CPU/GPU downtime just might lead to a cure for cancer! My team stats.
The datasheet claims that the resolution is 1440x234 - seems to be an odd resolution, widescreen perhaps?
correction - I found another document from Sharp specifying 480x234
Post Edited (parts-man73) : 2/10/2008 6:16:00 PM GMT
480 pixels of each color, R G and B... so 1440 in total... many datasheets do that.. confusing sometimes...
I have a few ideas in my head for what I'll use these for!
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Brian
uController.com - home of SpinStudio - the modular Development system for the Propeller
PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!
SD card Adapter - mass storage for the masses Audio/Video adapter add composite video and sound to your Proto Board
Wow these things are expensive new!
I heard some crazy analyst last year say something like "We're entering the age of the LCD". Great! So when will I be able to buy 100 color LCDs for $100? I'm still waiting for this wondrous age to begin
OBC
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no kidding! I googled the part # from the datasheet looking to see if anyone sold the bare screens new for a reasonable cost. Mouser can special order them, minimum quantity is 12 or 15, and they are over $500 each! If I was going to spend that much, Walmart has 32" LCD TV's for about the same price (not as portable though
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Brian
uController.com - home of SpinStudio - the modular Development system for the Propeller
PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!
SD card Adapter - mass storage for the masses Audio/Video adapter add composite video and sound to your Proto Board
Stepping all over both of us!
It looks like I might win one of these same LCD's on ebay! I'd love it if you could share some code on how you got it working.
(Unless an LCD is from a laptop, phone, pda, mp3 player, digital camera, toy, etc... - BIG PAINS TO USE)
It is the same code as TV video. I'll share the wiring that needs to be done.
The wires can be accessed from the external harness, so you may not need to open it up. But something tells me these have problems with a loose connector. When I tried to use the external wiring, it didn't work, which caused delay and confusion. You may need to open it up and solder right to the circuit board. it's pretty easy though, very wide spacing. I'll take some close ups of mine, and I just got another that I plan to convert soon. But my kids are trying to talk me into actually installing it into our Minivan.
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Brian
uController.com - home of SpinStudio - the modular Development system for the Propeller
PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!
SD card Adapter - mass storage for the masses Audio/Video adapter add composite video and sound to your Proto Board
* The Black wire is ground
* The wire with clear insulation can be connected to ground also
(it's the signal shield, attaches to the foil wrapped around the signal wires)
* Green - Video signal- attach to the center pin of the RCA jack
* Blue - Video ground - attach to outer ring of RCA jack
I had issues with a bad crimp on the pink wire terminal that goes into the plastic female connector on the wiring harness.
Those wiring harness issues are common, mine was similar, if in doubt, solder wires directly to the PCB on the opposite side of the connector, I had to do this on mine. Use the wire colors listed as a guide to know where to solder what. I never got a chance to do my other screen and photograph the results in the hectic days that led up to my departure.
Been on vacation the last week or so, I haven't had an internet connection, which has been a blessing and a curse. I have alot of reading to do to catch up with the forum and my emails.
I still am not home but I will be in a couple days.
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Brian
uController.com - home of SpinStudio - the modular Development system for the Propeller
PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!
SD card Adapter - mass storage for the masses Audio/Video adapter add composite video and sound to your Proto Board
http://lcd-panels-lcds.shopeio.com/inventory/details.asp?id=867&cat=Lcds&sub=Lcd Panels
http://lcd-panels-lcds.shopeio.com/inventory/details.asp?id=796&cat=Lcds&sub=Lcd Panels
Rick