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2nd Gameboy Zero

Posted: Fri Apr 14, 2017 5:57 am
by BadBert
I am going to build my second GBZ.

the first one works good :) I wanted to make another one to give away to my brother,.... but i now want to build a new one using this screen: ... 98031.html

and keep that one... and give away my first build to my brother :)

I am now trying to get enough info on using the HD screen. I want to keep the "original" gbz screen cut out.

so what i need to know:
- Can i still make the effective screensize what i want using the config file?
- can i use the audio from the screen to go to my amp/speaker? (can the Pi0 give hdmi audio?)
- can i keep the cartridge reader and functional cartridge (i think not?)

I have got some parts already, but still need:
- pi0 (going for the new W version)
- screen
- lipo
- screenprotector
- audio amp
- USB hub

all other stuff, i got already :) including some GB cases and broken GBs

If anyone has some tips, please feel free to respond here :D

Re: 2nd Gameboy Zero

Posted: Fri Apr 14, 2017 9:10 am
by McGyver
Thank you for waiting a couple of days...

Here some pictures of the HDMI display I used from aliexpress...
Hard to explain but the display looks more clear by eyes than the camera is capturing. Maybe caused by the screen refresh frequency. Not visible by eyes...
As I wrote previously in the other tread the screen ratio is something like 16:9 in stead of the 4:3 original... As I keep the cut-out from a previous BW display a managed to cover the space below and upon the display by a bigger screen label. Another argument for keeping the 4:3 cutout was to re-use my existing screen protection cover.
To get the right boarder visible I need to cut off the screen boarder label.
On addition I need to mention that I removed the touch layer (similar to another tread here). No need from my point of view during running retropie.
I installed the display 180 degrees turned to have the HDMI connector accessible from the bottom. My Pi Zero is located in the game catridge bay to have external access to the Micro SD Card. For wired HDMI connection I used an approx 15cm HDMI-Mini- to HDMI cable with stripped outer insulation and stripped off connector housing. (quite easy to remove with some help of heat and knife). The harness is internally insulated by aluminum foil. For avoid shortcuts to neighbor circuits I wrapped this harness afterwards by some tape.
I didn`t used the display board headphone output for using HDMI audio. As I wrote: this screen replaced an previous one, so I keep using my USB sound device.

Here my boot.txt file with HDMI settings specially for this display. Take care with other options I used e.g. SD card overclocking...
# For more options and information see
# ...
# Some settings may impact device functionality. See link above for details

# uncomment if you get no picture on HDMI for a default "safe" mode

# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
# overscan_left=-12
# overscan_right=-11
# overscan_top=-10
# overscan_bottom=-21

# uncomment to force a console size. By default it will be display's size minus
# overscan.
# framebuffer_width=320
# framebuffer_height=240

# uncomment if hdmi display is not detected and composite is being output


# uncomment to force a specific HDMI mode (this will force VGA)
hdmi_cvt 480 320 60 6 0 0 0

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display

# uncomment for composite PAL
# sdtv_mode=1
# sdtv_aspect=4:3

#uncomment to overclock the arm. 700 MHz is the default.

# Uncomment some or all of these to enable the optional hardware interfaces

# Uncomment this to enable the lirc-rpi module

# Additional overlays and parameters are documented /boot/overlays/README

# Enable audio (loads snd_bcm2835)


# Disable the ACT LED on the Pi Zero.
Internal pictures from the Gameboy will maybe follow during a couple of days, I will not open the gameboy now, just waiting for the safe-shutdown board to be installed.

From my point of view arguments regarding this screen:
-for sure the clear view without any noise in the picture
-less current draw compared to my previous BW display.
-5 Volt out of the box (you could power by micro USB but I soldered somewhere to the board to keep space)

-As usual the shipping time: I waited approx. 2 weeks for delivery to France
-some setup necessary regarding the screen orientation and proportion
-Gameboy display cutout maybe to be adapted against the "standard" screens.
-Display controller board does not fit into the gameboy: needs to be cut for some mm. (not difficult)
-I found NO way to adjust the brightness!!! There is no push-button on the board! Could be maybe adjusted via software by GPIO connection. (which I removed on my board :shock: ) But the display brightness is quite ok, even with daylight. I don`t know this technique name when the entering light is being reflected behind the LCD layer? Looks to be the managed on by display.
-no external accessible HDMI connection without use of additional devices: for me there is no need of external connection anymore.

Feel free for questions...
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Re: 2nd Gameboy Zero

Posted: Thu Apr 20, 2017 7:36 am
by BadBert
Thanks A LOT!!!!
awsome :)

one more question: is it not possible to alter the .txt file so the image fits the original cutout? So you wont have to "alter" the screen protector sticker?
On the left, bottom and top it seems to be fitting the original bw cutout?

Re: 2nd Gameboy Zero

Posted: Thu Apr 20, 2017 7:42 am
by VeteranGamer
any chance of an internal view....


Re: 2nd Gameboy Zero

Posted: Thu Apr 20, 2017 12:30 pm
by cobramike
Hi BartBert. Again nice build. I orderd 2 of these and also the 5inch variand from Aliexpress. But can you tel me why you dont use a higher resolution.

Greets Mike

Re: 2nd Gameboy Zero

Posted: Thu Apr 20, 2017 1:21 pm
by McGyver
Pictures from inside: maybe during the coming days. The reason: In the moment I closed my build by a thin boarder of aluminum tape on the edge of both half shells which I don`t remove for minor issues. It is really nice and well sticky :-)
I had to remove the screw holder in the battery bay for my huge battery size and saw no other idea for closure in the moment. I am working on an idea to get it closed by screws again but this will cost some time for assemble and realign the items inside... During the next days I will install my new arrived saved shutdown circuit and will use this opportunity to take some pictures from the inside.

For the screen resolution: 480x320 is the native one, provided by the supplier. Changing this upwards is useless: the Pi is possibly more busy for calculation and the screen controller board would transcode the resolution back to the native one...

Why I don`t changed the displayed screen size: first I didn`t want to crop the picture and waste pixels
Second: I didn`t wanted to squeeze the picture because you would resolve an unclear, washed image: same when you set your desktop monitor to many resolution smaller than the native one. Only resolutions divided by 4 are useful.
For example: squeeze 10 pixel by dividing by 3 are 3,3333 pixel. These ,3333 can not be displayed and are a unclear logical situation.

Re: 2nd Gameboy Zero

Posted: Fri Apr 21, 2017 12:44 am
by BadBert
oh, i thought is was a higher resolution screen?!

Re: 2nd Gameboy Zero

Posted: Fri Apr 21, 2017 7:22 am
by McGyver
No it isnt. You can link it to the price. All higher relolution displays in the scope of 3.5 inches are more expensive.
The only advantage in my mind is the digital connection compared to the analog composite.

Re: 2nd Gameboy Zero

Posted: Sat Apr 22, 2017 4:38 pm
by McGyver
As announced, pictures from inside...
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Re: 2nd Gameboy Zero

Posted: Tue May 02, 2017 1:37 am
by BadBert
OK, well...
just to get all the info: why would we use this screen then?
I thought i read on the forums that the resolution was higher on this screen...

i now use the BW type of screens... but want to have a sharper and better picture. :) Thought this screen would give me all of that :(
If i look at the pictures where they have a normal OS screen (desktop view) it shows really small letters that are perfectly readable... no way that is possible on the same resolution as the BW screens use?!