Gamer Builds Custom Nintendo Switch-Style Dock for 3DS

Years from now, when someone pulls an old New 3DS XL from a drawer and connects it to this handcrafted Switch-style dock, it will feel like going back in time. The system slides down with a satisfying click, its screen blazing onto the TV in crystal-clear, high-definition HDMI, and a Switch Pro controller springs to life in your hands.

In terms of hardware, the 3DS is a nice place to start; that’s where a USB-C capture card slips into place, grabbing the video signal directly from the motherboard. That signal is then routed to a Raspberry Pi Zero, which runs its own proprietary software and performs some fancy stuff behind the scenes to ensure that the output on the big screen is smooth and stutter-free. Boot times are measured in seconds rather than minutes because the Pi just enters a full-screen mirror of the 3DS display and moves on. Power enters through some new side connections soldered into the console’s borders, providing a continuous 5V that keeps everything nice and charged even while you’re playing for hours on end. The display scaling is regulated by a series of buttons on the dock’s side, allowing you to properly fit games like Mario Kart 7 on the screen, borders included.

Building this monster required a lot of precision, so KOUZEX meticulously mapped every inch of it with Fusion 360 before firing up the 3D printer to spit out the pieces. Then there came the assembly, which consisted of five little bits of glittery PLA that were epoxied together to form a base that is essentially a miniature reproduction of the Switch’s footprint. Front and center are two USB-C ports for power and data, as well as an HDMI out that works perfectly; simply plug it in and go. The 3DS slides effortlessly into the back, aided by the dock’s rails with no movement. Under the surface, there is a nice little structure of cables and soldered connections.

The controllers were the major pain point, since they were a puzzle that required several rounds of trial and error to solve. A modchip for the 3DS emulated button pushes from external inputs using a wireless GameCube adapter, but it all failed due to a voltage mismatch. So he had to start over using an N64 wireless adapter that occurred to run at the correct voltage of 3.3V, allowing it to pair seamlessly with the Switch Pro. Once connected via Bluetooth, the analog sticks functioned seamlessly with the virtual circle pad, with the triggers mapping directly to the shoulder buttons with no difficulties. Even during those frantic drifts down Rainbow Road, there was hardly any delay.

One issue that nearly ruined the entire endeavor was the 3DS falling asleep when you closed the lid. The dock keeps the lid open, but the switch believes it’s closed because the magnetic clasp is empty, so it goes into standby. This required placing a little CR2032 battery in place to deceive the switch into believing the lid was always open. After that, the console just runs all day, with the battery topped off and the screen locked on the TV. Best of all, the entire thing is no bulkier than the original charger stand.
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