[PREORDER] Charliplexing button PCB (Control 12 buttons via 4 GPIO pins!)

[1461748123]

Hello guys!
This is a button PCB for Gameboy Zero using charliplexing, a method that allows you to control several buttons via few I/O ports.


Wait, but why will I need this?
This board is design for people that wants to use DPI to drive their LCD and use PWM pin for audio output, and at the same time don't want to use teensy to control buttons. With DPI and PWM in use, you will only have 4 GPIO pins available. This board suits the situation perfectly.
With this board you can control X, Y, A, B, UP, DOWN, LEFT, RIGHT, START, SELECT, L, R with only 4 GPIO pins!
Okay then, but what do I have to do to make this board work after I purchase it?
I will provide a full tutorial on the forum for anyone to understand how this board works and how to use it. I will make a python code to drive this board and make sure that you have no problem with it.

I'm now accepting pre-order and the board won't manufacture unless enough users are interested in them (in this case 10 people). You can request a refund anytime before I make the order to the manufacturer. All the boards will be fully tested before I ship them out.
The source code will be provided after I reach the 10 preorder goal. Anyone can use, modify and spread the source code. You must give credit to me if you are using the code and commercial use are prohibited unless with a permission from me.

Price for each board: 9$

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[Helder]

Nice! I was thinking of designing one like this but seeing as you've got it set I'll leave it be. I'd love to see the tutorial and have this being demoed.

[Fleder]

Interesting. I read about your problems with those few left over Pins. Really fast work here.
But, are there no downsides, like less buttons pressed at the same time or something like that?
What are the downsides, if there are any, in contrast to the teensy method?

[1461748123]

Interesting. I read about your problems with those few left over Pins. Really fast work here.
But, are there no downsides, like less buttons pressed at the same time or something like that?
What are the downsides, if there are any, in contrast to the teensy method?

For now, I see no downside. The problem I have before is ghosting, which is a false input that will be created when multiple buttons are pushed. But I fixed it with adding the individual diode to each button.

[1461748123]

Nice! I was thinking of designing one like this but seeing as you've got it set I'll leave it be. I'd love to see the tutorial and have this being demoed.

I'm still working on the code but the tutorial should come out on this weekend I'm still thinking should I use python or c to accomplish the goal.

[joe7dust]

Have a few questions about this.

1) Would I be able to use it to control RPi0 running RetroPie to play GBA games inside of a DMG-01 shell?

2) How long till finished product would arrive at my door?

3) Does that $11 include shipping to US?

[1461748123]

Have a few questions about this.

1) Would I be able to use it to control RPi0 running RetroPie to play GBA games inside of a DMG-01 shell?

2) How long till finished product would arrive at my door?

3) Does that $11 include shipping to US?

Yes, you can use it to control RPi0 with RetroPie running. The code will basically simulate it as a keyboard.
When I reach the preorder goal, the product should arrive in 2 weeks if you live in the US.
No, to US you have to pay 7$ of shipping.

[joe7dust]

Have a few questions about this.

1) Would I be able to use it to control RPi0 running RetroPie to play GBA games inside of a DMG-01 shell?

2) How long till finished product would arrive at my door?

3) Does that $11 include shipping to US?

Yes, you can use it to control RPi0 with RetroPie running. The code will basically simulate it as a keyboard.
When I reach the preorder goal, the product should arrive in 2 weeks if you live in the US.
No, to US you have to pay 7$ of shipping.

Sorry but all the other parts will be here within a week and if it only going to be $2 less than a teensy I might as well get the teensy since it seems to be highly programmable and has already been used in many other builds.

[1461748123]

Have a few questions about this.

1) Would I be able to use it to control RPi0 running RetroPie to play GBA games inside of a DMG-01 shell?

2) How long till finished product would arrive at my door?

3) Does that $11 include shipping to US?

Yes, you can use it to control RPi0 with RetroPie running. The code will basically simulate it as a keyboard.
When I reach the preorder goal, the product should arrive in 2 weeks if you live in the US.
No, to US you have to pay 7$ of shipping.

Sorry but all the other parts will be here within a week and if it only going to be $2 less than a teensy I might as well get the teensy since it seems to be highly programmable and has already been used in many other builds.

I'm lowering the price to 9$. Like the description said, this board is design for people that doesn't want to use teensy or want to free up a USB port. I will went for the teensy route if I have enough usb ports

[joe7dust]

What did you use your USB port for? I'm guessing WiFi?

I plan to use the 2 composite pins for video and probably PWM for audio. Since I'm not doing TFT/Touchscreen I'll likely have tons of space left on the GPIO. I think I could actually solder each button switch to the GPIO directly and manually setup the controls somehow since I'll have so many free, but not sure how to do that...