Skipping the teensy

[Ivoah]

I noticed that a lot of projects like this used a separate microcontroller for handling input. While this works just fine, it is another component to buy and power. It seems that not many people realize that the raspberry pi can use the GPIO pins as a keyboard, with the gpio_keys kernel module. Notro has a good tutorial on how to set it up on his fbtft wiki. Keep in mind that although it's on the fbtft wiki, I believe that it's a native part of the Pi kernel. Even if it isn't it doesn't matter, as fbtft is installed by default on the newer OSes. Hopefully people can use this trick to save a few bucks when making handhelds.

[Helder]

I don't know where the Pi3 came about but this is simply an alternative to the other methods available and is geared towards people who want plug and play and not have to fuss with so many wires.

While we're on the GPIO pin route there is another method that Brian is looking into using and it uses only 4 GPIO pins. It all comes down to preferences and how much you can and want to do.

[Robvp]

A lot of people are actually using the GPIO, I would have done it myself too but I wanted a plug and play alternative so I'm using a USB gamepad instead

[Fox]

I don't know where the Pi3 came about but this is simply an alternative to the other methods available and is geared towards people who want plug and play and not have to fuss with so many wires.

While we're on the GPIO pin route there is another method that Brian is looking into using and it uses only 4 GPIO pins. It all comes down to preferences and how much you can and want to do.

So without a Teensy, you cannot use a USB gamepad?

[Robvp]

I don't know where the Pi3 came about but this is simply an alternative to the other methods available and is geared towards people who want plug and play and not have to fuss with so many wires.

While we're on the GPIO pin route there is another method that Brian is looking into using and it uses only 4 GPIO pins. It all comes down to preferences and how much you can and want to do.

So without a Teensy, you cannot use a USB gamepad?

You can, it's plug and play, I'm using one on my project

[Ivoah]

I don't know where the Pi3 came about but this is simply an alternative to the other methods available and is geared towards people who want plug and play and not have to fuss with so many wires.

While we're on the GPIO pin route there is another method that Brian is looking into using and it uses only 4 GPIO pins. It all comes down to preferences and how much you can and want to do.

Again, this method doesn't take any more wires than the teensy route, so why do you say "so many wires"?

[Helder]

I'm not using the teensy or plan to it and my mod will require 4 wires only, if you go like you said with the teensy and the GPIO pins as you suggest you around 12 to 13 wires. Your method requires the same as the teensy as you said but most people are too tech savvy and are following @wermy's guides to do this so they are following what they see in the guides and it's easier to some people to use the teensy so in the end you can go your route or the teensy and use the same amount of wires.

Maybe making a tutorial that most people can follow to use your method will get more followers to this method.

[Ivoah]

I'm not using the teensy or plan to it and my mod will require 4 wires only, if you go like you said with the teensy and the GPIO pins as you suggest you around 12 to 13 wires. Your method requires the same as the teensy as you said but most people are too tech savvy and are following @wermy's guides to do this so they are following what they see in the guides and it's easier to some people to use the teensy so in the end you can go your route or the teensy and use the same amount of wires.

Maybe making a tutorial that most people can follow to use your method will get more followers to this method.

How do you plan on doing it with 4 wires? Multiplexing of some sort? And also yeah, I plan on making a guide once I have all the parts ready for my build. I just bought the screen, and now am trying to find a broken GBA.

[Helder]

Damn phone typos made my message come out wrong. Anyways my board you can use a usb wire or wire the 4 usb wires to the pi or a hub.

I plan to do a pcb for the gba too but need to find my gba to get dimensions but won't tackle this just yet.

[brotherdawn]

If I were skipping the teensy and wanted to create my own pcb board for fun... Would it be wise to add some pull up resistors for pretty much all of the buttons? From what I see online, teensy has internal pull ups but only two of the gpio raspberry pi zero have them.

Been a while since I've done some circuit design... Just remember that pull up/down resistors can be helpful to avoid some issues. Might be a stupid question. Thanks to anyone who can offer some advice!