Wii U Gamepad zero/gamepi project thread

[evertith]

For those interested, this guy posted another video on his project this morning.

https://www.youtube.com/watch?v=yvppbsGhzXY

Based on his current experience with that 10 pin 0.5 pitch, I'm thinking it might be easier to tap into the traces/pads on the mainboard. But, this would require having a broken version from eBay for $50 or so bucks.

This is kind of what I was looking at:

[gnarlynick]

What do you mean lose the battery? Were you planning on using the original battery holder and a replacement gamepad battery like myself?

I would have to lose the battery well, the portion protruding into the case where the OEM battery would reside. This may not need to happen depending on the size of Kite's driver board though, but if I use the board that came with the screen, as it is now, the case won't close so the compartment molded into the case holding the OEM battery would need to be removed by dremel. I guess I will wait a bit and see what Kite shakes out for this project, there really isn't much space in there otherwise.

Something like this might be a good idea to take the battery outside of the case to maximize space inside for other components:


I'm already planning on removing the stack of 4 USB ports and the ethernet port from a pi 3 to shrink it down; maybe even cut down or entirely remove the GPIO pins, although I will be utilizing them to tie the controls into. I wanna do more emulation than is capable on the pi zero like N64 and other platforms of that generation. The joysticks on the gamepad make this a must. I don't see much reason to put a zero in here when joysticks aren't really utilized by the systems it can happily emulate. For me, it's pi 3 or bust with this project.


I don't know much about Kite's planned driver board, will it utilize the display connection on a pi 2/3? I don't know how feasible that is.

[evertith]

What do you mean lose the battery? Were you planning on using the original battery holder and a replacement gamepad battery like myself?

I would have to lose the battery well, the portion protruding into the case where the OEM battery would reside. This may not need to happen depending on the size of Kite's driver board though, but if I use the board that came with the screen, as it is now, the case won't close so the compartment molded into the case holding the OEM battery would need to be removed by dremel. I guess I will wait a bit and see what Kite shakes out for this project, there really isn't much space in there otherwise.

Something like this might be a good idea to take the battery outside of the case to maximize space inside for other components:


I'm already planning on removing the stack of 4 USB ports and the ethernet port from a pi 3 to shrink it down; maybe even cut down or entirely remove the GPIO pins, although I will be utilizing them to tie the controls into. I wanna do more emulation than is capable on the pi zero like N64 and other platforms of that generation. The joysticks on the gamepad make this a must. I don't see much reason to put a zero in here when joysticks aren't really utilized by the systems it can happily emulate. For me, it's pi 3 or bust with this project.


I don't know much about Kite's planned driver board, will it utilize the display connection on a pi 2/3? I don't know how feasible that is.

I didn't realize the pi zero can't do n64. Oh man. That makes me rethink pi3 as well. Mario 64 would be gold on this build.

[Racerboy]

From my understanding of it, Kite's display board will use GPIO and have HDMI-like quality, whereas composite would be slightly blurry.
(Hence why I'm going with a Teensy )

You really got me thinking about putting a Pi 3 in now but I'd want to plan out the battery and sizing/positioning of everything before I go ahead and cut out the battery holder.

The Teensy LC seems ideal for this project. It can accept up to 25 inputs, and I count 25 button/analog inputs.



I don't have a pi to test this on right now, but does anyone know what "ESC" does in-game? Does it quit the game or do anything useful? Because if it doesn't, the Home button could be bound to "Start+Select". Or just something that always brings you back to the main menu.

[gnarlynick]

I didn't realize the pi zero can't do n64. Oh man. That makes me rethink pi3 as well. Mario 64 would be gold on this build.

The pi zero can barely do Star Fox for SNES, and most 32x games I tried with it are hit or miss. It may be able to do some N64 titles but I wouldn't count on it. The pi 2 was very hit or miss with N64 as well, from what I understand, the pi 3 does it the best, although not with 100% compatibility. N64 all around is a tough system to emulate really, but the zero definitely can't really scratch the surface with it.

[gnarlynick]

From my understanding of it, Kite's display board will use GPIO and have HDMI-like quality, whereas composite would be slightly blurry.

You really got me thinking about putting a pi 3 in now but I'd want to plan out the battery and sizing/positioning of everything before going ahead and cutting out the battery holder.

Ya, I'm gonna hold off before doing any major case mods and see what advancements on the project the awesome people in this community can provide.

[Racerboy]

Just doing some small math, I think it might be possible to fit two of these Lithium Ion Polymer Battery - 3.7v 2500mAh batteries in case, along with a pi 3, all side-by-side-by-side, giving 5000mAh at the same 3.7v.

I thought about maybe stacking them on top of each other, but I took some measurements where if hypothetically you took out the battery holder, that would give you 0.488" of height to work with. The batteries are 0.300" thick, and this is not including the thickness of kite's controller board (and any electrical tape insulation that goes with it ) so that won't work.

However, I measured from the right post that supports the D-pad, all the way across to the post that supports the Y-button, and that gave me about 6.5" with a little room to spare. The batteries are 2" in width, so two batteries would take up 4" in width, and the Pi 3 is 2.3" in width, so all together that leaves you with 0.2" of wiggle room to distribute across the batteries and the Pi 3, not bad.

[gnarlynick]

Just doing some small math, I think it might be possible to fit two of these Lithium Ion Polymer Battery - 3.7v 2500mAh batteries in case, along with a pi 3, all side-by-side-by-side, giving 5000mAh at the same 3.7v.

I thought about maybe stacking them on top of each other, but I took some measurements where if hypothetically you took out the battery holder, that would give you 0.488" of height to work with. The batteries are 0.300" thick, and this is not including the thickness of kite's controller board (and any electrical tape insulation that goes with it ) so that won't work.

However, I measured from the right post that supports the D-pad, all the way across to the post that supports the Y-button, and that gave me about 6.5" with a little room to spare. The batteries are 2" in width, so two batteries would take up 4" in width, and the Pi 3 is 2.3" in width, so all together that leaves you with 0.2" of wiggle room to distribute across the batteries and the Pi 3, not bad.

Awesome find, I'm going to try and use as little components as possible in this build considering the space constraints. Absolutely essential components I can think of off the top of my head are:
-Raspberry Pi (Zero/2/3)
-Battery(ies?)
-Powerboost 1000c (do these support multiple batteries? If not, do multiple batteries require two powerboosts?)
-Stereo Audio Amp?
-Volume potentiometer
-Screen+Driver board
-Teensy LC potentially
-Wiring (Never underestimate the space wires can take up)

USB hubs aren't necessary if you're using a Pi 2/3 as they have ample amounts of USB ports you can tie off of. Also, a Pi 2/3 has a dedicated audio out so a low pass filter won't be necessary for this build, just would need a stereo amp I would assume for both the speakers included in the gamepad case. Am I missing anything in my list here? The biggest components in that list are the Pi, the Screen+Driver board and the batteries, everything else should be able to be slid somewhere in the case once those bigger pieces find a home.

[gnarlynick]

The Teensy LC seems ideal for this project. It can accept up to 25 inputs, and I count 25 button/analog inputs.



I don't have a pi to test this on right now, but does anyone know what "ESC" does in-game? Does it quit the game or do anything useful? Because if it doesn't, the Home button could be bound to "Start+Select". Or just something that always brings you back to the main menu.

I'm not sure on what 'Esc' does in console games (SNES, PC-Engine, etc.) but in MAME games it would leave the game in the same manner Start+Select does in console games. I'm currently thinking of wiring an 'Enter' and 'Esc' tac button into my Teensy on my GBZ build as those are buttons I find myself needing from time to time and need to find a USB keyboard to input them. If Kite's driver board is utilizing Teensy and there are 25 inputs on the gamepad itself, I may have to rethink my approach and use a Teensy as well. There's also a 26th button, labeled TV by the power button.

[Racerboy]

Here's the amp I was planning on using:
Stereo 3.7W Class D Audio Amplifier - MAX98306

Can't you just solder the Lipo's black/red wires to the same connection on the powerboost, making them one big 5000mAh battery?

I found this 10k-ohm slide potentiometer that seems to be the appropriate size...
10K Ohm Slide Potentiometer Pot 18mm - Pack of 2

I was just going to leave out the TV button since I can't think of a useful action for it, maybe a reset button