Author Topic: Razer Tartarus v2 Mechanical Switch and RP2040 Mod  (Read 633 times)

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Offline Lostdotfish

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Razer Tartarus v2 Mechanical Switch and RP2040 Mod
« on: Sun, 11 February 2024, 08:22:20 »
Hey all,  so I'm about two thirds of the way through this project so I thought I'd start writing it up.

I have always been a fan of the Nostromo style keypads for gaming.  Have my thumb be able to quickly do 4 keybinds using the D-Pad have become something I couldn't be without.  I started using these with the original Belkin Nostromo n52, then moved on to the Razer n52te, then the Tartarus v2 (I also have an Orbweaver kicking around, but that will be another story...).

My biggest gripe with these pads? Obselence through lack of software support... not to mention the dumpster fire that is Razer Synapse.

The goals of this project.
  • Replace the Mecha-mebrane switches with real mechanical switches.
  • Convert to QMK based MCU
Parts
  • Custom keypad PCB
  • Custom D-pad PCB
  • Custom Space PCB
  • RP2040 Stamp
  • 1N4148WS Diodes SOD-323
  • JST connector for USB cable (harvested)
  • TTC 11 encoder (harvested)
  • Wheel click tact switch (harvested)
  • Thumb button tact switch (harvested)
  • 4 x Kailh Mini Micro switches
  • 20 x Kailh Choc Mini Red switches
  • Keycaps

Teardown

Taking this apart is pretty straight forward.



These are the main screw locations holding the casing together. Once removed, it's fairly easy to finish disassembly. Note the screw hidden under the label.

Designing the PCBs

This was my first foray into PCB design.  It's been quite a learning curve...  Luckily another member had already completed a similar project and shared his PCB designs on Github.

https://geekhack.org/index.php?topic=107213.0

From these, I had a good headstart with board outlines and initial measurements.  I had to do a bit of reading up on how keyboard diode matricies work in order to redesign this PCB for QMK rather than direct connection...



I had hoped I would be able to direct connect the D-Pad and Space PCB but unfortunately QMK doesn't like mixing matrix and direct connection. So I had to redesign both of these to connect into my main matrix.



Then closed my eyes and hit the order button on JLPCB.  I was fully expecting this to never work in a million years...

A couple of weeks later, they arrived.



Putting it all together

Once my PCBs arrived, I started by hand soldering the diodes to the reverse of the main PCB.  I have an Andonstar microscope, so this was fairly easy. Doing this without magnification however would be tough. The SOD-323 diodes are very small.



In this image, you can also see the harvested JST connector so that I can use the original USB cable.

Flipping the main PCB over, I soldered in the RP2040 Stamp.  I chose the stamp as it breaks out the USB data pins for easy routing to the JST connector.  All the other RP2040 boards would have been more difficult to route the USB.  I didn't design the PCB with pads for the castelated Stamp and was intending to use pin header.  I ended up using a few pins (4, 1 in each corner and then 4 more for the USB D+ and D- and power and GND), then once they were soldered in and aligned, I could solder directly to the plated holes and it wicked through both the Stamp and the PCB making good connection.



Here you can also see the harvested EC11 encoder and wheel tact switch.

Build log to be completed - waiting for switches to arrive and need to build the D-Pad.

Building QMK

I have a running test firmware which is working nicely.  I'll add more details as I complete this project in the next week or so.





« Last Edit: Sun, 11 February 2024, 09:25:58 by Lostdotfish »

Offline Lostdotfish

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Re: Razer Tartarus v2 Mechanical Switch and RP2040 Mod
« Reply #1 on: Sun, 11 February 2024, 08:22:38 »
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Offline Lostdotfish

  • Thread Starter
  • Posts: 8
Re: Razer Tartarus v2 Mechanical Switch and RP2040 Mod
« Reply #2 on: Sun, 11 February 2024, 08:22:48 »
reserved