Gamebuino forum

Hi,

since i am waiting for the new Gamebuino, i built a simple clone:
then i ordered a mega2560 and a color screen (160x128). This is the result:
https://youtu.be/BvuHxESkmis
Resolution of frame buffer is 80x64. Since its SPI i was not able to scale it up to 160x128, as this would require 4 times more bandwidth. Currently the screen update takes about 9ms per frame.
I'm waiting for a parallel TFT

Update:
https://www.youtube.com/watch?v=dL2-o4VTIEI&t
Digger in color with fullscreen (upscaled to 160x128) via SPI.
Its not so bad as i was afraid of. maybe there are some improvements possible..
cycle counting could save some time:

Code: Select all

while (!(SPSR & _BV(SPIF))) ;

could become some NOPs to match the 17cycles delay between loading a byte to SPDR.

It looks nice!
Is the upscale what is responsible for the slightly slowdown?

Yes, as there are 30kB per frame to transmit. (444-color mode with lookuptable) Gamebuino needs 504Bytes per frame...

Next days i'll measure the fps

Nice one, I'm also redesigning an old board I made to be gamebuino compatible. Very first prototipe looks promising I'm sticking to the old nokia screen. Monochrome is enogh for me.

an actual image.
Running at 8fps in fullscreen. (sometimes 9, only 7 when sound is played)
Screenupdate itself needs 81ms -> this could getting better

/edit: 11fps, 53ms per frame for writing to screen.

/edit: disabled sound and got 16fps, 34.8ms per screen update (which is nearly full speed of SPI - 34.56ms for 30kB)
Enabling sound and call noInterrupts() at start of transfer and interrupts() at end has similar effect (beside sound output ), but getting time by micros() doesn't work anymore because interrupts are disabled