Question Controller help with Nintendo Switch-like Raspberry Pi Console

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ok so I’m building my own Raspberry Pi console based on the design of a Nintendo Switch

(features include a controller that is split into two parts and con connect to each other or the console, a dock for easy charging and HDMI out, and a Raspberry Pi running retro Pi.)

First off let me address that I know this forum isn’t really for raspberry pi projects, but i figured I’d see if anyone could help me with my problem.

Ok so my problem is this: I’m trying to Find a way to split my Bluetooth controller into two parts: one for the left side of the console and one for the right, while retaining the ability to detach the controllers from the console and attach them to each other to form a regular Bluetooth controller (sorry if that seemed convoluted).

So to be more specific my first problem is splitting the controller

My second problem is getting them to be able to detach from the console i was thinking that i could solder the buttons to a male USB plug on one controller and a female USB on the corresponding side of the console, running wires along the console to the other side, where a male USB will be connected to the console and a female USB connected to the other controller. This would allow me to plug the controllers into the console as well as into each other (since one controller has a male and one has a female USB), but the problem Is i don’t think i can do that since there are a total of 15 buttons on my controller and a USB cable only has two data ports. So i need help finding another way to attach the controllers.

Any help is greatly appreciated!
 

fibbef

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Hey Tech Flare! Just because a lot of BitBuilt modders are focusing on this console or that handheld doesn’t mean we’re about other projects as well. Your idea sounds cool and I hope we can help you implement it in a way that works the way you want.

So I think the first thing to realize is that only half of your controller will be Bluetooth. The other half is just disconnected buttons until the two halves are connected.

If you want to use some kind of common connector, which I think is a good idea, you’re going to need something with a lot of pins. One half of the controller would need pins for d-pad (or action buttons), start (select), shoulder buttons, and a joystick. By my count that’s about 12 lines. Although they’re not terribly easy to solder to, using HDMI jacks would have enough pins with some to spare for additional ground lines. If you decide not to include joysticks in your final build, that would eliminate a few lines, in which case USB 3.0 jacks could be used (9 pins).

Since the controller is Bluetooth, there’s really no need to wire controls to the Pi. With the controls attached to the tablet portion, the tablet would act as a pass-through, just feeding the signals from one side to the other. The way it would look would be like this:
-Right controller has buttons wired to male HDMI/USB/whatever jack.
-Male jack connects to female jack on tablet portion.
-Female jack on the right feeds to another female jack on the left of the tablet.
-Female jack on left connects to make jack on the left controller.
-Left controller houses Bluetooth circuitry; receives button signals from right through the jack.

Hope that helps. That all just started pouring out of my head and I just typed it up without seeing if it makes sense. Let me know if something doesn’t make sense and maybe I can draw a diagram of what I mean.

Edit: I just realized that if both of your controller halves have male jacks, they can’t directly connect to each other. You would need some sort of spacer (like the Switch’s joycon grip) that houses female jacks for the two halves to connect together. Otherwise you could put a male jack in one half and female in the other, but that means you’d have a male jack sticking out of one side of the tablet.
 
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Hey Tech Flare! Just because a lot of BitBuilt modders are focusing on this console or that handheld doesn’t mean we’re about other projects as well. Your idea sounds cool and I hope we can help you implement it in a way that works the way you want.

So I think the first thing to realize is that only half of your controller will be Bluetooth. The other half is just disconnected buttons until the two halves are connected.

If you want to use some kind of common connector, which I think is a good idea, you’re going to need something with a lot of pins. One half of the controller would need pins for d-pad (or action buttons), start (select), shoulder buttons, and a joystick. By my count that’s about 12 lines. Although they’re not terribly easy to solder to, using HDMI jacks would have enough pins with some to spare for additional ground lines. If you decide not to include joysticks in your final build, that would eliminate a few lines, in which case USB 3.0 jacks could be used (9 pins).

Since the controller is Bluetooth, there’s really no need to wire controls to the Pi. With the controls attached to the tablet portion, the tablet would act as a pass-through, just feeding the signals from one side to the other. The way it would look would be like this:
-Right controller has buttons wired to male HDMI/USB/whatever jack.
-Male jack connects to female jack on tablet portion.
-Female jack on the right feeds to another female jack on the left of the tablet.
-Female jack on left connects to make jack on the left controller.
-Left controller houses Bluetooth circuitry; receives button signals from right through the jack.

Hope that helps. That all just started pouring out of my head and I just typed it up without seeing if it makes sense. Let me know if something doesn’t make sense and maybe I can draw a diagram of what I mean.

Edit: I just realized that if both of your controller halves have male jacks, they can’t directly connect to each other. You would need some sort of spacer (like the Switch’s joycon grip) that houses female jacks for the two halves to connect together. Otherwise you could put a male jack in one half and female in the other, but that means you’d have a male jack sticking out of one side of the tablet.
That helped my so much! I never thought of using an HDMI cable for the controller! I’ll probably do that. I’ll research this a little more and come back if i find anything new or if i do something
 
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You could also use male and female header pins as long as you don't rely on them for structural support.
 
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OK so I think I’m going to use HDMI for the connection between the boards, but now i need help figuring out how to cut the board, because no matter how i cut it I’m going to have to cut a lot of traces.
 

Stitches

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OK so I think I’m going to use HDMI for the connection between the boards, but now i need help figuring out how to cut the board, because no matter how i cut it I’m going to have to cut a lot of traces.
How? A rotary cutter like a dremel is what we use for cutting boards. I find the thin cut EZ-Lock cut-off wheels are the best for it.
 
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How? A rotary cutter like a dremel is what we use for cutting boards. I find the thin cut EZ-Lock cut-off wheels are the best for it.
Well I can cut the board fine, but the problem with cutting it is I would have to cut a lot of traces in the process (see the pictures in my original post)

So what I’ve been thinking is to buy a broken WiiU Game Pad and use the controllers from that, and then wire that controller to a Bluetooth keyboard circuit board.
 

Stitches

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Well I can cut the board fine, but the problem with cutting it is I would have to cut a lot of traces in the process (see the pictures in my original post)

So what I’ve been thinking is to buy a broken WiiU Game Pad and use the controllers from that, and then wire that controller to a Bluetooth keyboard circuit board.
Wire the buttons to a keyboard? That'd probably work well, but you wouldn't be able to use joysticks like that. As for cutting traces, you can rasp the fibreglass off the copper with a knife or fibreglass pencil and solder thin wires to the traces. Then just solder the wires to your other PCB the same way.
 
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Ultimately, you could just buy official Nintendo Switch Joycons and then design the portable with them in mind. Work has already been done to make the Joycons RetroPie compatible, but still look into the software aspect before deciding on this.

But, If you really want something completely custom, you should be using a Bluetooth controller and wiring the button and joysticks to that. Trim the Bluetooth controller to the point where it will fit in one Hackcon. Then use perfboard with tactile switches for both Hackcon's actual interfaces.

I would just use a Teensy and scrap Bluetooth entirely, but that's my preference.
 
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I don't personally know, but I do know that people elsewhere are working on it. Check the retropie forums and the retropie github for more info.
 
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Ultimately, you could just buy official Nintendo Switch Joycons and then design the portable with them in mind. Work has already been done to make the Joycons RetroPie compatible, but still look into the software aspect before deciding on this.

But, If you really want something completely custom, you should be using a Bluetooth controller and wiring the button and joysticks to that. Trim the Bluetooth controller to the point where it will fit in one Hackcon. Then use perfboard with tactile switches for both Hackcon's actual interfaces.

I would just use a Teensy and scrap Bluetooth entirely, but that's my preference.
I dont think I am going to use real Joycons unless i have too.

On your second point about a Bluetooth controller: yes i have a Bluetooth controller, but i don’t know where to make the cuts. Maybe you could show me where to cut the board? Pics on the original post. Also, I️ don’t know what a Hackcon is.

I could try using a teensy, but I’ll have to look into how to get that to work since i know nothing about it.
 

ahrlad

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Wouldn't it be simpler to cut up two gamepads, keep the circuitry in each, and map each of them to one half of pad 1 in software? Then you could use each independently of the other.
 
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Something like this basically
The picture you attactched isn’t showing up...

EDIT: oh wait it showed up once I️ refreshed the page. Yeah, basically something like that.
 
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Wouldn't it be simpler to cut up two gamepads, keep the circuitry in each, and map each of them to one half of pad 1 in software? Then you could use each independently of the other.
I don’t know how to do that ;/ I’m probably just going to use a teensy.
 

ahrlad

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Teensies are great, but I don't think they're a good solution for a wireless use case like this. I think you're better off using a couple of cheapo bluetooth controllers like these:

https://m.aliexpress.com/item/32811514278.html
Or
https://m.aliexpress.com/item/32812338402.html

You could cut them up and wire one of them to the dpad and one to the face buttons, pair both of them with your pi, and map them to the correct input in config. Then you'll be able to use them independently when disconnected. It's how real joycons work with the switch after all.
 
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Teensies are great, but I don't think they're a good solution for a wireless use case like this. I think you're better off using a couple of cheapo bluetooth controllers like these:

https://m.aliexpress.com/item/32811514278.html
Or
https://m.aliexpress.com/item/32812338402.html

You could cut them up and wire one of them to the dpad and one to the face buttons, pair both of them with your pi, and map them to the correct input in config. Then you'll be able to use them independently when disconnected. It's how real joycons work with the switch after all.
No way dude. You just totally made my day! I’m totally going to buy that and feature your comment in my next video!
 
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No way dude. You just totally made my day! I’m totally going to buy that and feature your comment in my next video!
I hope it works like ahrlad says but I have my doubts. I tried it with two usb controllers in the past and it didnt work like this. Granted this was usb controllers and it might’ve been added in recent updates. I just looked up how to connect two controllers as one in retropie and I couldn’t find anyone reporting success so if you figure it out I would be interested in knowing what you did.
 

ahrlad

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I hope it works like ahrlad says but I have my doubts. I tried it with two usb controllers in the past and it didnt work like this. Granted this was usb controllers and it might’ve been added in recent updates. I just looked up how to connect two controllers as one in retropie and I couldn’t find anyone reporting success so if you figure it out I would be interested in knowing what you did.
This guy seems to have gotten it working with regular joycons: http://www.instructables.com/id/PiSwitch/

It does seem like a fair bit of config is needed, but it's definitely possible
 
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