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View Full Version : Hacking the display/touchscreen from a Magellan RoadMate.



JohnGay
04-05-2012, 01:04 PM
I just got a Magellan RoadMate with a broken power connector and thought I'd pull the display/touchscreen out of it and see if I could make it work.
The Part Number: TD035STEB1 returns exactly 1 page in Google, in chinese. There's a Word Doc that looks just like the web page and a PDF that comes up blank for me.
It's got a single flex connector with 50 contacts. 12 are not complete and divide the rest into groups. I'm hoping so poking around can render some clues. And maybe people familiar with these displays can shed some light and where and how to start.

I thought about going after the GPS as well, but there's only 1 large board and lots of shielding soldered down pretty good so I'm thinking that'll take more effort than just buying one for my QuickStart. My time's pretty expensive to me (-=.

Cheers,

John Gay

Rayman
04-05-2012, 05:04 PM
John, if it was a Tom Tom, I might have had something for you...

But, you can still check out my 4.3" and 3.5" display solutions for Propeller on my website...

I also have a new SSD1963 adapter and driver that can drive these screens in full, 24-bit color...
I have a prototype adapter for Samsung and Newhaven 4.3" LCDs. But, maybe you could find an adapter and wire something up for yourself...

darreno
04-05-2012, 05:36 PM
I found a pdf for the TD035STEB1 with all the pinouts and timings.

microcross.com/TD035STEB1_Product_Specification_Ver_03.pdf

JohnGay
04-05-2012, 09:25 PM
OK. So it's got 6 bits each for RGB, a video clock input, Data Enable, 4 pins for the touchpad and a pair of backlight LEDs. Power seems to be +12V, -6.5V, 5V and 3.3V.

The dumbest way to drive this would be bit-bang it with 24 data lines from my prop. Or find a driver chip that talks this display's language. Either way, it should be fun hacking this and seeing how it works.

Cheers,

John Gay

Duane Degn
04-05-2012, 09:54 PM
OK. So it's got 6 bits each for RGB, a video clock input, Data Enable, 4 pins for the touchpad and a pair of backlight LEDs. Power seems to be +12V, -6.5V, 5V and 3.3V.

The dumbest way to drive this would be bit-bang it with 24 data lines from my prop. Or find a driver chip that talks this display's language. Either way, it should be fun hacking this and seeing how it works.

Cheers,

John Gay

I think Ray doesn't use all the bits for RGB lines so he saves some pins. I think the Prop has a hard time keeping an 18 bit color image in RAM anyway so you losing a few bits might save both pins and memory.

Rayman
04-05-2012, 11:38 PM
Very true... For most of my stuff, I just use a modified version of the VGA driver to give a 6-bit display, just like you get with VGA (just at lower resolution).

I just recently delved into driving these with SSD1963 chips for 24-bit color display. This adds quite a bit to the cost though...

JohnGay
04-06-2012, 03:49 PM
Well, I'm new to driving displays like this. At 240x320x18 pixels is quite a bit.
Maybe one cog can fetch a line at a time from a buffer?
As far as just driving fewer bits, wouldn't that mean the colors would be wrong? If the LCD expects 6 bits per color, I can't just drive 3 bits without the color being offset, right?
I'm still trying to budget for rayman's 3.5" display, but my financial advisor hasn't approved the purchase yet.

Rayman
04-06-2012, 04:52 PM
The "used" 4.3" screen+breakout is pretty well priced, you might take a look at that one...
Also, if you don't need the "touch" part, I'm about to sell new NewHaven 4.3" screens (no touchscreen) and breakout at a very low price too...

JohnGay
04-06-2012, 06:13 PM
Yes, I'd been looking at that one too. Actually, I was referring to my:
Whole
Income
Financial
Evaluator
Who fails to see any value in these gadgets I like to buy. Especially when I then want to buy add-ons to go with them. But I'm still working on adding to my QuickStart bit by bit.