sudomod

i'm trying to get a 2.2 TFT screen working with one of Helder prototype PCB

(anyone got one of these working or experienced the same)

my wring seems ok, and what leads me to believe that is the screen is working (powering on and displaying)

the issue is....




the display is jerky... and doesnt get better with time... the longer its on it gets a little worser


Helder suggested that it could be a refresh rate issue....

i tried googling about this, and didnt find anything (not to say it not out there)



i know im not far off from it working properly, just need a nudge in the right direction.....


i am using wermy pre-made image for the mintyPi (not sure if thats the issue)


thank you.....

That's really odd! Never seen one do that before!

If you can, try starting from scratch and then following the guide in my signature, see if that does the same

moosepr wrote: ↑

Thu Aug 03, 2017 5:20 am

That's really odd! Never seen one do that before!

If you can, try starting from scratch and then following the guide in my signature, see if that does the same

Thanks...

I'll do that first...(shame, I was hoping to avoid this, wermy img saves alot time)


Just a side note...
Do you think, in anyway it could also be a wiring issue...

Or a dud screen....

If your wires are as short as possible is should be ok. Are you using the 2.2 add-on board? If so how much extra slack is there on the ribbon? Maybe shield the ribbon?

Helder wrote: ↑

Thu Aug 03, 2017 8:16 am

If your wires are as short as possible is should be ok. Are you using the 2.2 add-on board? If so how much extra slack is there on the ribbon? Maybe shield the ribbon?

There is some slack in the ribbon cable (I've got a shorter one order)... (How would you recommend to shield it)

But I'm also considering not using it and just doing direct wires from pcb to pcb...


I'm gonna try a fresh install (just in case) and if that doesn't resolve it, it's got be a wiring issue

Actually before you start from scratch try changing the speed in

/etc/modprobe.d/fbtft.conf

Could just be your screen doesn't like the normal speed

moosepr wrote: ↑

Thu Aug 03, 2017 12:24 pm

Actually before you start from scratch try changing the speed in

/etc/modprobe.d/fbtft.conf

Could just be your screen doesn't like the normal speed

just did the fresh install, and then i saw your post....

but, it doesnt happen on the fresh installl (obivously the speed must be way off)

i'm gonna make a backup of the fresh install img, and retry with wermy img again and try changing the speed....


what speed would you recommend...

Well the faster the better really. My initial guide sets it at 16000000 which works, but limits the FPS you can get. The highest I have had working is 99000000 although it will depend on cable length and such. Anything over that seems to kill it.

moosepr wrote: ↑

Thu Aug 03, 2017 2:31 pm

Well the faster the better really. My initial guide sets it at 16000000 which works, but limits the FPS you can get. The highest I have had working is 99000000 although it will depend on cable length and such. Anything over that seems to kill it.

thanks...

ok...
strangely.... didnt have much success with wermy img (not sure why)....
but the fresh install i did, i was able to get it stable at 69000000 (have to setup retrogame now).... now i have got a long ribbon cable connected (about 8cm) and have got a shorter one on order.... hopefully that might let me up the speed a little...

in the menu fps shows around 60fps, but i'm sure that not going to be the same in game (but sonic seems fine on initial test)


main thing is that it works, so onto the next stage of the project...