Go Down

Topic: ILI9341 slow on arduino (Read 174 times) previous topic - next topic

haxan

Hi,

I have successfully interfaced a 2.4" TFT screen using the Adafruit ILI9341 library on my Arduino Mega2560. After running their graphics test example, i can see that overall performance is quite slow.

There is a similar thread there http://forum.arduino.cc/index.php?topic=265806.0

But i wanted to start a new one as the one above has a different direction.

So my issue is:

How to speed up the screen interface? I am willing to move to Arduino Due if there isn't much difference in Mega and Due. The reason is i have already written alot of code which is working on Mega such as Keypad, IR Communication, SimpleModBus Implementation. I dont want to throw all that away. I have read the specs of both boards. Other than performance boosts and different chip on Due and the fact that it has 3.3V logic level, is there anything else that might not work while porting from Mega to Due ?

Or is there an easier method to increase the screen speed please do share.

P.S: I am not willing to add Teensy 3.1 as its not available locally and will just be too much change.

haxan


olikraus

Hi

A lot of data needs to transfered to the display. Additionally the data rate on the SPI bus is not so high for the Arduino Mega.
Because of speed issues, i started my own graphics library. It might be faster here and threre, but do not expect a wonder.
Such a display is simply to much for an 8-bit controller.

http://code.google.com/p/ucglib/


Arduino Due is about 4x to 6x faster with Ucglib.

Oliver

haxan

Thanks Olikraus!

I will checkout your library. I dont have an Arduino due as yet. Just a question, will my Arduino mega code work on Due without issues or will i have to change quite a lot of stuff?

Also in another thread i was just reading, ( http://forum.arduino.cc/index.php?topic=265806.0 ). MarkB mentions DMA.

I have searched little bit about it and it says to increase speed of SPI when using DMA mode. I am a total noob in such things so my newbie question is, is it possible to run Arduino Mega in DMA mode somehow or is it only for Due?

haxan

Bytheway, your demo is pretty impressive and is fairly fast (other than the 3d Box) simulation.

Can it be ported for this screen http://www.buydisplay.com/default/3-5-lcd-display-tft-module-320x240-serial-spi-touch-screen-arduio which uses SSD2119 controller? This screen has support for upto 16.7M colors

MarekB


is it possible to run Arduino Mega in DMA mode somehow or is it only for Due?


DMA is available only in Due.

olikraus

Hi

Code with Ucglib will run accross all official Arduino platforms without (or only minor) modification.
SSD2119 is not supported.

Oliver

Go Up