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(WIP) Bouke's first GBZ

Posted: Thu Jul 20, 2017 2:16 pm
by bouke
Here is my first Game Boy Zero build log. Disclaimer: This will not be a quick build probably.

Currently in the process of waiting for parts to arrive and experimenting with some of the features I want to build into the GBZ.

Parts List
Parts List (click to expand/collapse)Show
Pi and Storage: Case, Buttons, Pads, PCB Controller: Screen and Connector: Batteries and Charging: Audio: Other Random Parts:
  • Some random (silicon) wire, resistors, capacitors, transistors etc. I have laying around...
ATTiny167 and I2C Communication
Currently in this other post (http://www.sudomod.com/forum/viewtopic. ... 521#p37521) talking about I2C communication between an ATTiny167 and Raspberry Pi. The ATTiny167 can do analog reads of the battery voltage and ambient light and communicate this with the Raspberry Pi. The ATTiny167 will also handle the shutdown of the Raspberry PI by monitoring the toggle slide switch and control the NeoPixel and LCD backlight.

Edit: First ATTiny167 has arrived however I accidentally blew it up by shorting some of the 5V outputs... New one is ordered! :shock:

The Screen
Disassembled the screen into three parts: the touch layer, screen and controller board. Furthermore I removed the headers from the controller board since they are not needed, I will also be removing the audio jack connector (here I will connect the amplifier, audio over HDMI) and backlight switch and cut off a piece of the controller board where there are no traces (the part with the Kedei text). Since touch is not really needed, inaccurate and made of a plastic "blurry" layer, it will not be used.
Screen Disassembly (click to expand/collapse)Show
Image
Touch Layer, Screen and Controller Board
I did some experiments by hooking up the power button connections to a PWM signal from my Arduino and this works quite nicely, together with the ambient sensor it will be used to "dim" the screen at night so I will not be blinding myself. :lol:

Also ordered this screen https://nl.aliexpress.com/item/Raspberr ... 62038.html which is sometimes on sale for around 10 dollars. Seems to be an updated version of the "Kedei" screen I am currently using, will definitely update this post with a comparison between the two.

To be continued...

Re: (WIP) Bouke's first GBZ

Posted: Thu Jul 20, 2017 3:25 pm
by YaYa
Sitting with popcorn :lol:

Good luck for your build !

Re: (WIP) Bouke's first GBZ

Posted: Thu Jul 20, 2017 6:05 pm
by tinkerBOY
Following and waiting..😃

Re: (WIP) Bouke's first GBZ

Posted: Mon Jul 31, 2017 4:02 am
by BadBert
interested how you are going to fiddle with the brightness of the screen.
Are you going to use a pot to make the brightness variable? That would be awsome....
(is that even possible?)

ben benieuwd ;)

Re: (WIP) Bouke's first GBZ

Posted: Mon Jul 31, 2017 4:43 am
by Eccho
Zo veel nederlanders in deze forum xD

Re: (WIP) Bouke's first GBZ

Posted: Tue Aug 01, 2017 11:41 am
by bouke
BadBert wrote:
Mon Jul 31, 2017 4:02 am
interested how you are going to fiddle with the brightness of the screen.
Are you going to use a pot to make the brightness variable? That would be awsome....
(is that even possible?)

ben benieuwd ;)
I use a PWM signal on the brightness LEDs (basically replacing the switch which is on the board with wires going to an Arduino currently). I ordered an ambient light sensor and I am going to experiment with that but I also thought about adding a potmeter in the spot where the contrast slider on the original Gameboy normally goes.

I will posts some more updates soon.

Re: (WIP) Bouke's first GBZ

Posted: Wed Aug 02, 2017 12:13 am
by BadBert
Adding a pot like the original contrast wheel, controlling the screens brightness would be awsome...

hope that is possible!

By the way, is that switch not just the on/off switch for the whole screen?
Or only for the backlight?

Re: (WIP) Bouke's first GBZ

Posted: Wed Aug 02, 2017 5:37 am
by bouke
BadBert wrote:
Wed Aug 02, 2017 12:13 am
By the way, is that switch not just the on/off switch for the whole screen?
Or only for the backlight?
Just replied to your PM but also wanted to post an update here for other people who might be wondering the same.

I did a test with an Arduino Uno and Potmeter connected to the place where the switch used to go and I get a PWMed LED backlight.

EDIT:
The backlight switch is indeed directly connected to the input of the LED driver chip, the PT4103. According to the datasheet that chip supports PWM dimming and therefore it works. Therefore the backlight can be controlled by providing power (5v) to the screen using the header pins or micro usb and then providing a PWM signal to the input of the led driver (the switch).

Re: (WIP) Bouke's first GBZ

Posted: Mon Aug 21, 2017 1:16 pm
by Kthuen
Hi Bouke
Sounds like a genious little hack. How dell does it work? And do you have any pictures og the wiring? :)

Re: (WIP) Bouke's first GBZ

Posted: Mon Aug 21, 2017 2:13 pm
by neolith
This looks interesting, I like build logs - followed. :D

BTW, your link for 'Gameboy DMG button PCB' leads to the case. ;)
Thanks for making the list though, I appreciate the effort!