Pipo's ZeroBoy Project

[Governor Hippo]

Hi Everybody
I hope this is the right corner of the forum to start the journey to enlightenment through the Zeroboy project.
First things first:
As I am new in this forum I like to introduce myself and take the chance to see if there is any knowhow or Zeroboy veteran nearby.
I am a 27 years old electrical engineer from Berne / Switzerland (anyone nearby?). I started with the Retroboy project about a year ago. But never finished it, as I am a perfectionist and didn't like the huge mess it was with my old Rpi. But thanks to the Zero and later on the compute module from Raspberry I now have the perfect tool to realise my vision of the project.
Of course I will document everything here, so you guys can learn from my mistakes
To finish my introduction I will post some questions that went unanswered in this forum (or I am just to stupid to find them).
[spoiler="answered Questions"]-Are the PCB-data from the "common ground dmg button pcb" from kitsch-bent open source or has someone something like it drawn on his computer? (I ask because I would like to expand it to my needs).

The boards are open source and here is one I uploaded that you can do whatever you want to it. You need Eagle Cad software though.
https://github.com/Helder1981/Game-Boy- ... roller-PCB

-Has anyone tried the Retropi with a compute module from Raspberry?

Interested to see how your build goes I actually bought the compute module and adapter and retropie works fine on it! (a little awkward to load onto the MMC but it's all documented on Pi website). My plan was to use it and make a PCB with it, but for the moment I'm just using the zero as it actually uses less space when mounted.. the issue with the CM is that with the DIMM adapter it uses quite a lot of space and is a really awkward size, and where I wanted components it didn't fit but as I said very interested to follow your project!

The benefit being that when the CM3 (Compute Module based on the Pi3 CPU) comes out, it would be an easy upgrade for a huge amount more powerful board!

-Does anyone know where to get the connector from the Gameboy ROMs? (except salvaging them from Gameboys)

take a look at some of the action replay/game genie style cheat cartridge as they contain a cart connector and can be found cheap on ebay, Failing that try a NDS Slot 2 connector it will need the ends filing down or cutting away as they were narrowed to stop GB carts being inserted

- Do you even want to see my progress or has it been done so many times that noone's interested anymore?

I'm sure I speak for many when i say that WIP/Progress photos are very welcome as everyone has a different take on the project,

-Has anybody already drawn the GameBoy Classic case or knows where to get it?

Try those:
https://grabcad.com/library/retro-nintendo-gameboy-1

[/spoiler]
-Has anyone ever sold his project? (Have a few friends who want one, so I'll be making three at the same time)



Thank you very much in advance and I am looking forward to many nice conversations and awesome projectreports from you guys.

Governor Hippo Out

Edit1: inserting all the answers to the questions because of viewability. (Thanks guys)
Edit2: readability

[Helder]

The boards are open source and here is one I uploaded that you can do whatever you want to it. You need Eagle Cad software though.

https://github.com/Helder1981/Game-Boy- ... roller-PCB

[FreddySalted]

I'm sure I speak for many when i say that WIP/Progress photos are very welcome as everyone has a different take on the project, You're the first I know of using the compute stick afaik. Take a look at some of the action replay/game genie style cheat cartridge as they contain a cart connector and can be found cheap on ebay, Failing that try a NDS Slot 2 connector it will need the ends filing down or cutting away as they were narrowed to stop GB carts being inserted

[Governor Hippo]

Thank you for all you replies, they are really helpful.

To clear some things up. I will build this RetroPi Zero with the Raspberry Zero. With the aquired know-how I want to create an easy template (all-in-one print) for further RetroPi projects. (Maybe for selling or modding old Gameboys for an allowance?)

Update 1:

Yesterday I got my dremel and got the courage to mutilate the front of my GameBoy. Don't worry I ordered three broken ones. So I don't thin out the herd and risk the survival of the endangered DMG-01

Important notes:
-If you dremel from the inside, dont dremel away the whole elevation of plastic. As it is larger as the sag for the screen in the front!
-Don't dremel away the whole sag for the screen, as it is to big. Measure the screen and cut out the measured size only!!
[spoiler="Case modification"]

From the back.

IMG_20160704_183722.jpg (3.71 MiB) Viewed 14635 times

And from the front.

IMG_20160704_190202.jpg (4.02 MiB) Viewed 14635 times

As you can see i cut the plastic screen from the original enclosure with an exacto knive. The transpartent part is the size of the animated screen and the blackened out part is where I cut to much. Another advantage of only cutting a rectangle is, you don't need to round the corner of your plastic screen. It will look more professional as my non-fitting version.[/spoiler]
Update 2:

Today I had the guts to open and solder a perfectly good display. I went through the display mod guide on the Wiki and ended up with the first version of the BW-display mod.
[spoiler="5V display mod"]

Desoldered IC and rerouted Powersupply

IMG_20160705_134457.jpg (2.81 MiB) Viewed 14594 times

After soldering under a microscope (because I am old and this shit gets smaller every year) I sweated some blood as the display only flashed images. It worked like a charm after uping the max. current.

~5V Voltage

IMG_20160705_134422.jpg (2.52 MiB) Viewed 14594 times

Running modded Display

IMG_20160705_134331.jpg (3 MiB) Viewed 14594 times

[/spoiler]
Update 3:
With the help of a friend and his 3D-Printer, I was able to model the support for the A- and B-button. They are just now getting printed for the X- and Y-buttons. As soon as they are done I will drill the holes and glue the support in place.
[spoiler="Buttonholder V0.1"]

3D-model of the button-holders

Button v1.jpg (63.81 KiB) Viewed 14515 times

[/spoiler]
I then downloaded the template from http://space.kitsch-bent.com/DMG_4butto ... mplate.pdf. Printed it out and drilled with a small drill center holes and then with a 11mm drill the real-size button holes.

Do not drill the buttonholes with a 11mm drill. The material is to weak and it will jam
[spoiler="drilling oval"]As you can see in the following pictures, the drill got jammed and the holes are now uneven and too big. Additionally the case has some cracks. For the next time I will drill small holes and dremel out the rest.
Edit: The problem was not the 11mm drill but the jump I made from 4mm to 11mm. Next time I will try to increase the size by 1mm or maybe 2mm at the time. I think the holes will get better when drilled as when I dremel them.

Backview of the case

IMG_20160706_125608.jpg (4.04 MiB) Viewed 14496 times

Frontview of the case

IMG_20160706_125559.jpg (3.73 MiB) Viewed 14496 times

[/spoiler]

I don't have the buttons with me right now. But as soon as I am home I will see if the printed holders are big enough and how ugly the case will look from the front with all the cracks and stuff
[spoiler="Buttonholder V0.1 in case"]

with 3D-printed button holder

IMG_20160706_125941.jpg (3.08 MiB) Viewed 14496 times

[/spoiler]

What's up next?
-Check if the buttonholders are ok and assess the damage of my drilling.-> not to bad, will work for the prototype and POC
-3D-print a holder for the display.->I will just glue it in and design a holder later for the next gen


I'm sorry for any spelling errors or misused words. English is not my first language. But it would be much appreciated if you could point out any improvements you see, so I can learn and get better.

Thank you

Editlog:
edit 3: Update 3 (3D-model)
edit 4: readability

[Ninjameep]

very interested in seeing how it turns out aswell, as i have the same pi o:

[Fleder]

-I need to draw the complete gameboy case in a CAD-programm to organize the inside. (Has anybody already drawn the GameBoy Classic case or knows where to get it?)

http://www.stlfinder.com/model/gameboy-2
http://www.stlfinder.com/model/nintendo-gameboy
http://www.stlfinder.com/model/gameboy-4

[Governor Hippo]

-I need to draw the complete gameboy case in a CAD-programm to organize the inside. (Has anybody already drawn the GameBoy Classic case or knows where to get it?)

http://www.stlfinder.com/model/gameboy-2
http://www.stlfinder.com/model/nintendo-gameboy
http://www.stlfinder.com/model/gameboy-4

Sadly those models are only the outside. I would need the insides modeled too, as to organize everything

[Fleder]

Sadly those models are only the outside. I would need the insides modeled too, as to organize everything

Try those:
https://grabcad.com/library/retro-nintendo-gameboy-1
https://grabcad.com/library/game-boy-cl ... l-design-1
https://grabcad.com/library/1989-nintendo-gameboy-1
https://grabcad.com/library/nintendo-gameboy--1
https://grabcad.com/library/nintendo-gameboy

[Governor Hippo]

Update 3 is added to my original post, and I just ordered 5 PCB's from the model of Helder (Thank you very much again, I need to learn Eagle asap ) . I will add it as is so I can finish my project. As soon as V1.0 is up and running I can start making improvements (like not drilling oval buttonholes ).

Are the shematics and the layout of the PWM Audio Buffer Boards open source?

If I order some X-Y Buttonboards, do I need to keep something in mind, like thickness or coating?

[Governor Hippo]

Update 4:
As I tested the buttonholder I printed I realized something. I have no deepening on the front for the X- and Y button, therefore the buttons have to come out a little further than the originals to guarantee the same "button pressing experience". So my friend drew a new model of the buttonholder without the 1mm base, to allow the buttons to come out further on the front.
[spoiler="Comparison of the two versions"]

Old and new 3D-printed button holder

IMG_20160711_103904.jpg (2.82 MiB) Viewed 13864 times

[/spoiler]
The PCB's I ordered should arrive today. Therefore I will be able to test the two holders for their "button pressing experience" and decide which to take.
Would anyone be interested in me printing some and selling them?
Are the shematics and the layout of the PWM Audio Buffer Boards open source?
[spoiler="schematics"]

Schematics from adafruit

raspberry_pi_audiofilter.png (56.83 KiB) Viewed 13847 times

To answer my own question I found this on adafruit:

How Audio Works on Other Pi Computers

The Broadcom chipset used for the Pi does not have a true analog output. Instead, two pins are PWM (pulse-width-modulated) at very high speeds, and filtered. The PWM frequency has to be at least 10x as high as the highest frequency we want to replicate in audio. Then, by adjusting the duty cycle of the PWM, we can 'fake' an audio signal.

Audio is 20Hz to 20KHz, and the PWM output from the Pi is 50MHz so we can easily filter the high 50MHz out (and anyways it cant be heard).

Looking at the Pi B schematic, we can see PWM0_OUT and PWM1_OUT are the left and right channels. R21 and R20 are voltage dividers to get the 3.3V signal down to about 1.1V max (that's the max peak-to-peak voltage you want for audio line level.

C20/C26 works with R21/R27 to create an "RC low-pass filter". You can calculate the cut-off frequency with 1/(2*pi*RC) = 1/(2*pi*270*33*10-9) = 17865 Hz which is pretty close to 20KHz!

C48/C34 acts as a DC-filter capacitor, it only allows AC through - speakers and headphones don't like DC voltage!

Finally 8AV99 are ESD protection diodes. That's to protect the Pi from static coming in and zapping the PWM pins.

https://learn.adafruit.com/introducing- ... io-outputs[/spoiler]

If I order some X-Y Buttonboards, do I need to keep something in mind, like thickness or coating?

Edit 1: I answered my own questin about the diodes.