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minimal pi

Posted: Wed Jan 25, 2017 12:55 pm
by moosepr
Hi guys

I have been on the retropie forum for a while now, just found the sudomod forum and thought i would share my last masterpiece

I had been wanting to make a little Pi based handheld ever since the Zero came out, but couldn't get my hands on one. When i finally got one I was stuck for ideas as to what kind of case i wanted, so i kinda made it without the case!!

I started off with a li-po battery I had lying around. I have measured it to be 2500mah, really thin, came out of an old power bank.

On the front, we have a cheepo 2.2" spi screen (ebay special £6 ish), flanked by 2 stripboard button arrays.

on the back is the Pi Zero, a cheepo li-po charge/protect board, and a small arduino acting as a power switch (dfRobot uHex if anyone is intersted)

Image

Image

The spi screen isnt as bad as people make them out to be. Sure the process that copies the screen to the spi bus adds some overhead, and the gpio button bit probably adds some too, but i have not had any issues.

It plays gameboy/gameboy colour/NES/SNES/gamegear/mastersystem with ease.

N64 games run (slowly!!) but the buttons dont seem to work, so i used it as a battery life test, and just broke 10 hours!!!!

The only problem, its a bit on the fragile side!! 5 mins in the same pocket as anything metal and there will be fire!!!

Pete

Re: minimal pi

Posted: Wed Jan 25, 2017 2:33 pm
by wermy
Nice! I actually just got the exact same screen up and running for another project. What settings are you using on it and what's your performance like (on the screen specifically)?

Re: minimal pi

Posted: Wed Jan 25, 2017 3:09 pm
by moosepr
i have actually just been reinstalling it all, so i have all the settings to hand.

Currently running

sudo modprobe fbtft_device custom name=fb_ili9341 gpios=reset:25,dc:24,led:18 speed=16000000 bgr=1

i have had the speed up to 46000000 and added fps=60 and it still copes (although i doubt it is actually running at 60fps)

i have actually been experimenting with the ili9341 screens, you can actually ditch the pcb, there is nothing on there that is of major use (other than the 0.8mm pitch FPC)

Re: minimal pi

Posted: Wed Jan 25, 2017 3:46 pm
by thedudester80
Still one of my favorite builds. Great work!!!

Re: minimal pi

Posted: Wed Jan 25, 2017 3:47 pm
by wermy
Cool. Are you running that in conjunction with fbcp? I've got mine runing fbtft_device=adafruit22a since it uses the ili9341 as well. I've got speed set to 80000000 (as adafruit does) and fps set to 60. It's not 60fps (and there is a bit of screen tearing) but it looks/works pretty well! Good enough that I'd play games on it, anyway.

Re: minimal pi

Posted: Wed Jan 25, 2017 3:51 pm
by moosepr
thedudester80 wrote:Still one of my favorite builds. Great work!!!
Thanks man, fancy seeing you here!
wermy wrote:Cool. Are you running that in conjunction with fbcp?
Yeah fbcp for the screen, it's the only way really. I think there are versions of MAME that can output straight to the frame buffer, but just for simplicity is easier to just pipe everything

I think the tearing is just the nature of the screen really. Only noticeable when large chunks of the screen change quickly. Can't complain with how cheap the screens are though. Found some for less than $2 each in bulk (minus the PCB)

Re: minimal pi

Posted: Thu Mar 23, 2017 8:24 pm
by yogurtcup
putting a bare Raspberry Pi on the sofa makes me feel anxious :?

Re: minimal pi

Posted: Fri Mar 24, 2017 12:25 am
by moosepr
yogurtcup wrote:putting a bare Raspberry Pi on the sofa makes me feel anxious :?
Ha ha ha ha, I like to life dangerously! :D

Re: minimal pi

Posted: Sun Aug 20, 2017 6:49 pm
by C.Egret
Your cheap lipo protect board can use a slide switch like the powerboost?

Re: minimal pi

Posted: Mon Aug 21, 2017 12:20 am
by moosepr
You can just use a slide switch in place of the little hexagonal Arduino board. That is basically trying to be a clever switch