Lcd Nightmare

[Robster]

I'm trying to initialise and use the LCD in raw mode. Seemed easy, and the display hardware is really funky. Or it will be, once it's up and running. But I just can't shift that stripey mess that U-Boot displays, and I know my LCD is fine because the GP2X logo comes up fine if I boot into Linux.

Now, I dumped all the registers when I was in Linux, and I now have a colossal table in a C program which loads those values into the registers in raw mode. But I haven't succeeded in getting so much as a flicker from the LCD!

All of the ports are set up as they are in Linux, as is everything even remotely display-related (including the clock and power manager). So what can I be doing wrong?

I unzipped kernel4 to see if I could RE the LCD initialisation code, but I gave that up as a bad job after an hour or so.

Is there something really simple that I'm missing? Any advice gratefully received!

 

[Robster]

A little more info: I've looked at the ME kernel code and repeated what it does, with no effect.

Also the LCD is model TS35ND2501 made by Top-Sun but I can't find any data on it.

 

[Inopia]

I'm sorry I can't help you, since I don't have the real HW. The only thing I can think of is that perhaps the order in wich you set the values on the LCD controller may be of importance.

In any case, hang in there!

 

[Squidge]

He's got it working now on his device, and on Reesy's. However, it doesn't work on mine

 

[DJWillis]

He's got it working now on his device, and on Reesy's. However, it doesn't work on mine

​

Hmmm, is Reesy's a dev-kit or pre-release GP2X?

Could there be differances from dk to pre-release , oh well, I would offer to test but ......

 

[Robster]

Sorry about not updating this sooner!

I did solve the LCD problem, I had to floggle some GPIOs as well as setting the CPU registers.

If you want to try it on your system, just grab this file and run it under U-Boot. If you're interested in the source, let me know and I'll send it to you.

 

[Reesy]

Me! Me! drsms_reesy"at"yahoo.co.uk thanks Rob

 

[Robster]

Source is here. It will build with any arm-elf-gcc that has newlib built in, if you have a gp32 toolchain then you're good to go. Or you could follow the instructions in the GP32 section of my site.

You'll possibly need to change a few things in the Makefile, but I'm sure you're capable of that!

 

[Squidge]

If GPH hadn't used an external chip, I could have written a small program launchable via uboot that took an exe over the usb port and executed that. It what I intend to use once we have a launcher and fully functioning SD driver.

 

[skeezix]

Very cool stuff; I suppose ditching the OS shouldn't be too hard after all this work you guys have done. (Though i have no problem living on an OS ..all this Linux dissing is silly; course ditching the OS is more cool Besides, means we can operate without the likely-GPL-voilating version

How do you use uboot to boot an alternate app? (ie: There will be a lot of 'newbie' questions soon, since none of us have had a device to screw on

jeff

 

[Squidge]

GPH still violate the GPL even if we delete Linux, as u-boot is GPL and no source code is provided

uboot has two commands - 'loads' and 'loadb', the first allows you to upload srecords to the device, and execute them. The second allows you to upload binary files via the Kermit protocol. Both are incredibly slow - Kermit manages about 1.4KB/sec at 115200 baud. 'loads' is slightly faster and is the preferred method.

Of course, once the SD driver and replacement boot loader are done, we can reflash the units, and boot from SD card instead. I'm looking into uploading executable and data files via USB to save wear and tear on the SD card, and making testing stuff that bit more tolerable (constantly swapping cards between the device and your card reader is never that much fun).