The Fat Chameleon

Features

The Fat Chameleon is a grid type orthogonal keyboard with two optional layouts in one single PCB. Being able to break off the bottom row allows both a 5x12 layout similar to the popular Preonic and a 4x12 layout similar to the equally popular little brother Planck on the same PCB.

Using the more common 19.05 mm grid spacing (vs Preonic & Planck's unique 19 mm) this PCB fit's several popular 'aftermarket' keyboard cases intended for JJ40/JJ50 and BM40 and similar PCB's without modification. (Please read below!)

Being fully hot-swap and with PCB mounted stabilizers ¹, Chameleon adds support for up to four encoders and a bottom row allowing either a single stabilized 2u key or two 2u keys in the middle, allowing for a layout that suits most users. If used as a 5 row keyboard, the bottom encoders can alternatively be placed at the edges on the second row, but not more than one per corner.²

The PCB is designed such that you can install hot-swap sockets for all the options of the bottom row, and dynamically swap the keys and stabilizers, and have either a full 1u grid, or your choice of 2u keys without any soldering needed to swap layouts.

The Chameleon features 8 bottomfacing RGB LEDs for underglow effects. These can alternatively be used for layer indication or similar, all depending on the users skill progamming in QMK.

Please Note! This PCB does NOT fit an original OLKB Planck/Preonic case!

Main Features:

• QMK and VIAL compatible, fully programmable keyboard
• RP2040 MCU, Dual-core Arm Cortex M0+ processor, flexible clock running up to 133 MHz
  • 264 KB of SRAM, and 2+ MB of on-board Flash memory (max 64 KB adressable in QMK/Vial) ³
  • USB-C connector to host computer, (USB 1.1 device and host support)
  • Low-power sleep and dormant modes
  • Drag-and-drop programming using mass storage over USB
• Kaihl hot-swap sockets for Cherry MX compatible switches (3 & 5-pin) ⁴
• Cherry Style PCB mounted stabilizers (Clip-in type preferred) ¹
• Two main layouts:
  • 5x12 with 58 to 60 keys
  • 4x12 with 46 to 48 keys (Break off bottom row)
• Configurable bottom row (Full hot-swap, no soldering):
  • Full 1u grid
  • 1x centered, stabilized 2u key
  • 2x centered, stabilized 2u keys

Optional add-ons:

• Support for up to 4 rotary encoders (one encoder per corner)²
• Optional RGB underglow (8 pcs SK6812 mini-e)
• FR4 Front plate (FR4 material, same as PCB), with full layout options (Black / White). Se below for listed tested cases.

These options requires additional components not included in this listing and sold separately.

Assembly

Little or no tools at all needed! The PCB can be delivered fully built and ready to use, with all layout options soldered and with rotary encoders and RGB added per your choice. These additional components (encoders/RGB) are not included in the price of this PCB and needs to be purchased along with the PCB for this too apply!!!

Ready to Use:

The PCB is fully populated with all the hotswap sockets for the choosen layout size as default. This allows you to swap between all the available bottom row layouts without soldering, only needing to disassemble from the case and swap out stabilizers and switches as needed.

• Ready to use - Mount it in a case and add switches.
• RGB LED's purchased with the keyboard are soldered, tested and functional according to layout size.
• Encoders purchased with the keyboard are soldered, tested and functional. Please leave a note with their desired placement!

DIY Kit:

As a DIY kit the PCB is delivered at it's full size (5 x 12) as a barebones but functional PCB, with all the small and difficult SMD components, like the USB port and the RP2040 MCU with all it's components already fully soldered and tested. As such the PCB can be connected to a computer, have the layout selected in Vial and you can test each switch position, out of the box.

All remaining components are DIY friendly and easy to solder, and no previous experience soldering is needed (although certainly preffered) to complete the keyboard.⁵

The larger and easier components like the hot-swap sockets are left unsoldered, allowing you to pick the exact layout you prefer, both for the bottom row and for encoder placement.

Breaking off the bottom row for a 4 x 12 layout is easily done with basic tools like a small set of pliers and a sharp utility knife.

• Main SMD components - Pre-soldered and Tested
• Hot-swap sockets - Solder yourself!
• Optional Encoders & RGB LED's - Solder yourself!
• Break off bottom row - Break off yourself!

This option also allows the use of some models of screw-in stabilizers, since these can conflict with some sockets, and require plastic/fiber washers to avoid shortcircuits, as you can solder only the needed sockets and leave out optional ones. In fact, technically you can also have 2u keys on the second row of a Preonic if you so desire.

Case & Plate

The PCB design is made to fit any existing cases for JJ40/JJ50 & BM40 PCB's.

The list below is in no way exclusive or exhaustive, and I fully expect there are other cases that will fit the PCB. These will likely be advertised as being compatible with these more common PCB's.

Cases (notably for JJ40/JJ50) with an integrated plate is limited to the layouts supported by the plate/case, usually either a full grid or MIT layout.

Cases verified to work:

These cases are tested and verified to work with the PCB.

• JJ50 Aluminium & Acrylic Case - Plate included in case, no extra plate required.
• JJ50 Stainless Steel Case - Plate included in case, no extra plate required.
• JJ40/BM40 Aluminium Tray Case - Plate included in case, no extra plate required.
• JJ40 Aluminium & Acrylic Case - Plate included in case, no extra plate required.
• Poseidon PSD40 Case Anodized - Plate is an optional add on to the case, above option suggested.
• Poseidon PSD40 Case Electonplated - Plate is an optional add on to the case, above option suggested.

Mounting hardware is associated with the case, and not delivered with the Chameleon PCB and Plate. Check what hardware is included in your specific case!

Front Plate

A front plate in FR4 (PCB core material) is available as an add-on, but may not fit all cases. To be as much a "one size fit's all" plate, this plate has rounded corners, which may leave gaps in the corners on some cases.

This plate supports all the available layout options for the PCB.

Plate Drawing

¹ Clip-in stabilizers are preferred, as they can clip into the PCB holes with all sockets installed. Bolt-in stabilizers can still be used, but you will need a felt/plastic washer or similar to avoid short circuiting the sockets with the metal bolt heads, and/or select what sockets to install.

² The two encoder footprints for each corner are connected to the same IO-pins, and cannot function independently. Adding two endoders to the same corner will simply make them function as one encoder.

³ Depending on parts availability, this can be delivered with a 4 MB or 8 MB FLASH EEPROM. QMK's base code can directly adress no more than 64 KB in runtime, and for wear leveling purposes this uses an additional 64 KB of EEPROM for a total usage of 128 KB, which leaves the remaing part as storage.

⁴ Please note that the Chameleon supports only Cherry MX type switches (3 & 5 pin), NOT Kaihl Choc, as they require a different PCB and plate design.

⁵ Soldering experience is not needed, but it certainly helps. And if you have never ever held a soldering iron, please ask in discord, and I'm happy to help recommend tools, or how to practice first, and how to solder to avoid destroying things.

Normal handling time is 3-5 working days (Predominantly done on weekends). Build items usually take 1-2 weeks.

All packages are represented to the courier/customs at their true value, and all responsibility for import fees and taxes resulting thereof lies with the buyer. DDP is applied where available.

Please note that when selecting a shipping option clearly marked as ‘uninsured’ or without tracking, you accept the responsibility for packages lost in transit.

All items are sold with a 24-month limited warranty, as per (2011/83/EU). Shipping of items returned for repair or replacement is solely the responsibility of the buyer. (This includes taxes and/or customs fees resulting from incorrect/incomplete shipping documentation.)

The SE "Act on Distance Contracts and Off-Premises Contracts" (SFS 2005:59) & The EU "The Distance Selling Directive" (97/7/EC) allow returns initiated within 14 days of receiving the item. Shipping of returned items is solely the responsibility of the buyer.

Please note that in the case of kits with multiple components, warranty to the individual components cannot be applied to the resulting build, and does not cover physical damage from incorrect soldering or handling by the end user. Please test active components (controllers) and initiate a warranty claim for manufacturing defects BEFORE you start to solder them!