Pipo's ZeroBoy Project

[Ford873]

i would be interested in one of the button holders. would make for a much cleaner build.

[Camble]

I'm guessing the 3.3v rail is to pull the voltage up. Not sure what the voltage from the PWM pins is tbh. The diodes will be there to prevent a short to ground.

[Ford873]

Could the design also be modded to add the 2 pins / posts that hold the rubber button pad in place? or is it not really needed?

[Governor Hippo]

Could the design also be modded to add the 2 pins / posts that hold the rubber button pad in place? or is it not really needed?

I would have to ask my friend, as the pins are very small and I am not sure how good that'll get on a 3-D-printer. The PCB's didn't arrive yesterday, so I have to test them today, but I guess it doesn't need the pins.

I am designing/ ordering some PCB's for the PWM-audiohack. Someone interested?
[spoiler="Designed the PWM to Analog Print for the Raspbery Pi Zero"]

Layout

PWM to Analog.png (3.42 KiB) Viewed 12048 times

I would be very gratefull for some feedback on this PCB as it is my first design with Eagle. Maybe some help on design rules and other questions concerning Eagle.[/spoiler]

Concerning the audio output. Is an amplifier necessary? When yes, how much amplification does it need? Is there somewhere a schema of one (only found a mono amplifier online)?

[JA88AtheHUTT]

As soon as V1.0 is up and running I can start making improvements (like not drilling oval buttonholes ).

I found when drilling the holes in my case that if you start with a 2mm drill bit and step up in 1mm increments the holes are much cleaner and do not damage the case.

[Ford873]

Could the design also be modded to add the 2 pins / posts that hold the rubber button pad in place? or is it not really needed?

I would have to ask my friend, as the pins are very small and I am not sure how good that'll get on a 3-D-printer. The PCB's didn't arrive yesterday, so I have to test them today, but I guess it doesn't need the pins.

I am designing/ ordering some PCB's for the PWM-audiohack. Someone interested?
[spoiler="Designed the PWM to Analog Print for the Raspbery Pi Zero"]PWM to Analog.png
I would be very gratefull for some feedback on this PCB as it is my first design with Eagle. Maybe some help on design rules and other questions concerning Eagle.[/spoiler]

Concerning the audio output. Is an amplifier necessary? When yes, how much amplification does it need? Is there somewhere a schema of one (only found a mono amplifier online)?

From reading the forums on here yes an amplifier is def needed. Regarding the pcb your designing Helder has already designed one and made it available to everyone.

https://oshpark.com/shared_projects/qUEOjE0n

[Governor Hippo]

Time for another update(5):

The button PCB's designed by Helder arrived yesterday. Thus I was able to test the printed button holders.
[spoiler="Everythings fits perfectly"]

Button PCB from Helder

IMG_20160712_170447.jpg (3.7 MiB) Viewed 12011 times

backview

IMG_20160712_172357.jpg (3.66 MiB) Viewed 12011 times

frontview

IMG_20160712_172349.jpg (4.27 MiB) Viewed 12011 times

Display, buttonholders and button PCB

IMG_20160713_130819.jpg (2.91 MiB) Viewed 12011 times

[/spoiler]

As I am sure that they work perfectly I am now selling them, if you're interested PM me
[spoiler="Buttonholder design V1.0"]As requested I added the two pins to hold the rubber button pad in place, and it fits.

Buttonholderdesign V1.0

gb_button.JPG (259.29 KiB) Viewed 12011 times

Printed button holder

IMG_20160713_125945.jpg (3.64 MiB) Viewed 12011 times

[/spoiler]
As an audio amplifier is necessary, I implemented a PAM8403 Chip on the designed PWM board. I know that Helder already designed all of it, but I want to learn to do it myself.
[spoiler="PAM8403"]

My schematics for the PAM8403 Amp

Unbenannt.JPG (64.41 KiB) Viewed 12011 times

https://www.openimpulse.com/blog/wp-con ... iagram.pdf[/spoiler]
Shall I open a sell thread to sell the buttonholders and additional button PCB's? Is someone interested in a PWM , PAM8403 or combination board?
I saw that there is a displayholder to screw in the back of the GameBoy, are the 3D Files opensource?

Special thanks to @Helder for the support

[Kilren]

I didn't look through your entire forum. Did you get the power working for the screen? It looks like I have the same screen driver (except different colors) and I have a fairly easy solution.

Flip your board over, on the bottom side, one of the six holes (with the holes on the bottom) does the VCC3# (can't read the last character # on mine). If so, then it can run perfectly simultaneously on 5v and 3v.

I did this without cutting anything off, so if you have your mileage may vary (assuming they're identical boards).

[spoiler="How I wired mine"]
Sorry about the yellow, didn't realize it was a poor choice until I saw it hosted.
Based on looking at the front of the pi, seeing the SD Card slot on the left[/spoiler]

[Governor Hippo]

Audioupdate:

I have seen that all of you solve their audio problem with the PWM-board and an amplifier based on the PAM8403. Something about that chip bugged me and I spend the weekend researching what it is.
After 40 pages of Helders PCB selling thread and a lot of information I got from him personally (via mail), I found out what it is. The PAM8403 is a powerful Audioamp in a small package. Ideal for the Zero-Pi you say? NOPE The PAM8403 is an audio amplifier designed for speakers, not for headphones or speaker (singular). The difference you ask? Quite simple. The PAM8403 has no common GND and is therefore unusable for headphones. Okay unusable is a strong word, what I mean is it works as long as its mono and you only use one channel not both.

I found some alternatives:

[spoiler="Adafruit Mono 2.5W Class D Audio Amplifier"]This is also just mono. Works, but not what I want. I want stereo![/spoiler]
[spoiler="TDA1308"]Normal OP-AMP[/spoiler]
[spoiler="LM386"]Normal OP-AMP[/spoiler]
[spoiler="LM4880"]Exactly what I was looking for. Simple stereo analog input and stereo output with a common ground. I will use this one. Even has the schematics for a separate speaker channel that gets cut when headphones are inserted.[/spoiler]

Seems like I will just buy a normal OP-AMP and not a whole solution like the PAM8403. I will create a board with the PWM-Analog sound and the amplifier on it. Would someone be interested in getting one, else I will directly implement it in my project and not bother making a separate board.

[Helder]

LM4880 has a switching circuit in the datasheet but you need a separate amp for the speakers, so if you have the PAM8403 already you can just tie the 2 together in a similar fashion.