AdaFruit 1.8" 18 bit color TFT display

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AdaFruit 1.8" 18 bit color TFT display

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Started 4 years ago by pra
Latest reply from bobc

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pra
Member

Given that Adafruit's library code, with unchangeable constant values for width and height, could never have successfully put this device in landscape mode, and that this code probably came from the Chinese manufacturer, I'm pretty certain we are the first to ever try Landscape mode. If I were you, I'd look at the clock divider settings; the clock may not be fast enough to handle the much longer horizontal sync time needed for landscape???

Having (I hope) nicely passed the buck of solving this issue to you, I will still be very interested in the outcome! Meanwhile, back to learning about FPGAs and VHDL.

Posted 4 years ago #
Zouk
Member

Haha, sure.

What I might even do is just write a wrapper to properly transpose all coordinates so it can be happy pretending it's running in portrait mode. >_>

Posted 4 years ago #
pra
Member

Except I'm pretty sure that it's a chip or chip setup issue, so I doubt anything you do with a wrapper will make any difference :-(

Posted 4 years ago #
Zouk
Member

Well, here's my logic:

The behavior that clued me in that landscape mode wasn't working great was a line of colored noise along row and column 0 (in terms of portrait mode coordinates).

These do not present when the chip is initialized in portait mode, as in your demo code that ran when I first got the display running.

So, if I instruct the microcontroller to write everything to the screen rotated 90 degrees (rather than telling the chip to rotate its coordinate system and screw everything up), it should stay happy. Should. Maybe. >_>

...or am I just wishfully remembering that the messed up rows only occur in landscape mode?

Posted 4 years ago #
pra
Member

You are right, that should work. A lot of work, better you than me (but I would like a copy of the lib when you are done :-)). BTW, I just tried playing with FRMCTL1 RTN, front and Back Porch settings (+ and -) along with setting TEAR LINE Modes 0 and 1 in all possible combinations and accomplished absolutely nothing.

I am definitely going FPGAing now!!

Posted 4 years ago #
Zouk
Member

Looking at it, it's going to require not much work - I think I'm going to start by only modifying the setPixel() function (or whatever it's called). That will take care of most of it, and the rest can be dealt with on a case-by-case basis.

FPGA's... you're a better man than I. A friend gave me his Spartan 3E development board when his class finished with it; I've tinkered a bit, but I decided to hold out until I can get a copy of the IDE they used. After years of C-ish languages, VHCL is *really* obtuse. Apparently they were writing in C++ in whatever IDE it was. Want.

Posted 4 years ago #
supermac
Member

please send me a copy, thanks!

Posted 4 years ago #
pra
Member

Supermac - you need to email me at PeterRArcher@hotmail.com so that I have your email address

Posted 4 years ago #
poslathian
LeafLabs

whats all this fuss about landscape mode?

surely

What I might even do is just write a wrapper to properly transpose all coordinates so it can be happy pretending it's running in portrait mode. >_>
is a perfectly reasonable solution here...

Posted 4 years ago #
pra
Member

Yes it is - there was no fuss, only disappointment we could not make it work with the hardware. Zouk is going to write the wrapper, and hopefully will share when done.

Posted 4 years ago #
Zouk
Member

Wow! I got in the rhythm of working on the project that involves this display and completely forgot about this thread. I did get it running pretty well in landscape mode without much difficulty. I'll post code when I have access to my primary computer again. Until then, I'll explain what I did.

I modified the lowest level stuff possible - drawFastLine(), drawPixel(), fillRect(), and maybe drawChar(). I'll have to go back through and look. Prettymuch anything that calls setAddrWindow() and starts writing via SPI needs modification.

All I did was change up the logic so that the lower left and upper right corner of any "landscape mode" operations you do would be the ones fed to the setAddrWindow() function, rather than the upper right and lower left as would be in portrait mode. Also, any height/width checks need reversal.

Two additional things of note. One, the display seems to work fine at SPI 9MHz. Two, fillRect() is bugged. Any rect you draw will be one pixel too long on one end, so it will render improperly. So a 10x10 square will actually be 11px long in one dimension, so you'll get an 11x9 rectangle with a little pixel tumor where the 100th pixel went. Discovered this and fixed it when I was duct taping the library.

Posted 4 years ago #
pra
Member

Great work!! - I'll be interested in getting the code when you get the chance. I knew the display worked fine at 9MHZ, the SD card doesn't however. It can only handle 4.5MHZ.

Posted 4 years ago #
Zouk
Member

Ah damn, I might do switching between them or something. I've not looked at the SD card code yet; if the sketch supports writing to it, that would be a really fantastic alternative to adding an EEPROM chip to my project.

Posted 4 years ago #
pra
Member

I'm sure the SDFat library supports creating/writing files as well as reading them. I also had the problem with my other LCD endeavor where the touchscreen only supports a slow SPI speed and the larger LCD pretty much made 9MHZ mandatory. I put in new SPI.begins in every touchscreen read function, restoring it back to the LCD speed before exiting the function. You can probably do similar with the SD

Posted 4 years ago #
Zouk
Member

Still away from my main computer, but I did sit down on my laptop and write a little tool in C# to determine 12-bit colors. Just 3 0-255 sliders for RGB, a color swatch, and text boxes to copy the color in 24 / 18 / 16 / 12 bit color. Dunno if anyone else needs something like that; if anyone needs it, I can upload the program and the project files. Not sure if something like that already existed, but I was bored, needed it, and couldn't find it on the web.

Gonna build a little font creator next, if anyone needs something like that?

Posted 4 years ago #

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