Open-source analog hall effect keyboards — every key knows its exact depth. Custom firmware, Nova desktop utility, and open hardware.
Traditional keyboards are binary — pressed or released. MARS keyboards know exactly where every key is.
Each key sits above a hall effect sensor and a tiny magnet inside the switch. As you press down, the magnetic field changes continuously. A 12-bit ADC reads 4,096 distinct levels across the full 4mm of travel — giving you sub-0.1mm precision.
This unlocks features that are physically impossible on traditional mechanical keyboards:
Four boards, one shared platform
75% layout — 81 keys + encoder + 0.85" TFT display
60% layout — 64 keys + encoder
65% layout — 66 keys + encoder — wireless
65% layout — 68 keys + split spacebar — wireless
Every key can do more than just type a letter
Remap every key to any HID keycode. 4 independent layers with MO (momentary) and TG (toggle) switching. Supports transparent keys that fall through to lower layers.
Tap a key for one action, hold it for another. Transform any key into a dual-purpose input with configurable hold threshold.
Assign a modifier+key combination to a single key press. One key outputs Ctrl+C, Alt+Tab, Ctrl+Shift+T, or any combo.
Analog depth-aware keystrokes. Assign different keycodes to different depths — shallow press does one thing, deep press does another.
Resolve conflicting directional inputs for competitive gaming. When A+D are pressed simultaneously, SOCD cleaning determines the output.
Assign quick macro shortcuts to any key. Execute common actions with a single press — open apps, trigger system commands, or paste text.
Your keyboard becomes a USB gamepad. Analog key depth maps directly to thumbstick axes — partial press = partial tilt. 250Hz report rate.
Record multi-key sequences and replay them with a single press. Build complex input sequences for productivity or gaming.
Stack up to 4 complete keymaps. Switch between them with MO (momentary hold) or TG (toggle). Each layer can have its own LED colour indicator.
0.85" 128x128 IPS TFT powered by LVGL on a dedicated CPU core. Upload GIFs, see Spotify album art, type notes, monitor PC stats — all on your keyboard.
The display runs entirely on Core 1 of the RP2350B via LVGL. Core 0 handles USB, hall scanning, and LEDs — zero contention. MPR121 capacitive touch enables gesture navigation: tap, swipe, hold. Screen content can be cast live to Nova Utility.
Configuration software for all MARS keyboards — Electron desktop app + WebHID browser mode. 9 themes.
Visual keymap editor — click any key to remap. 4 layers, MO/TG switching, media keys, presets.
9 effects across 3 zones. HSV colour picker, gradient editor, per-key painting, colorway presets.
Per-key actuation from 0.1mm to 4.0mm. Live depth preview, sensor calibration, rapid trigger.
Upload and manage animated GIFs on the VLT's 128x128 TFT. 11 slots, 1 MB each.
Connect Spotify to stream album art and track info to the VLT display in real time.
10+10 profiles, 9 colour themes. Import/export configurations.
Click to cycle through Nova's 9 themes:
9 built-in effects across 3 independent zones + 4 startup animations
4 boot animations play when the keyboard powers on
3 independent zones: Main Keys (per-key RGB), Ambient Strip (underglow), and Status Indicators (layer/profile). Each zone runs its own effect. SignalRGB support for system-wide sync.
Per-key actuation, rapid trigger, and sensor calibration
Simultaneous Opposing Cardinal Direction resolution — 8 configurable pairs, 3 modes
Both keys cancel out — neither active
Best for fighting games
Most recently pressed key takes priority
Best for FPS games
First key pressed holds priority
Best for defensive play
Default pairs: A↔D and W↔S (WASD). Up to 8 pairs, each with its own resolution mode. Toggle globally with KC_SOCD_TOG.
10 keymap profiles + 10 lighting profiles stored in flash
All profiles survive power cycles and USB reconnects. Stored in on-board QSPI flash.
Switch profiles via Nova, encoder, or keycode. Status LED shows active profile colour.
10 keymap profiles and 10 lighting profiles — mix and match any combination.
Rotary encoder with PIO hardware polling and layer-aware keymaps
EC11 rotary encoder with PIO hardware polling at 25kHz. Adaptive press-wait-release for all keycode types. Step accumulation with clamp prevents runaway during stalls.
2.4 GHz wireless for Saturn60, Mina65, and Taki65
Low-latency wireless link with USB dongle receiver. Auto-pairing, channel hopping, and retry logic.
Rechargeable LiPo battery with TP4056 charging IC. NTC thermistor monitoring for safe charging.
Auto sleep mode, LED dimming on battery, wake-on-keypress. USB-C charging while in use.
Complete comparison of all MARS keyboards
| Specification | VLT / Nocturne75 | Saturn60 | Mina65 | Taki65 |
|---|---|---|---|---|
| Layout | 75% | 60% | 65% | 65% (split space) |
| Keys | 81 | 64 | 66 | 68 |
| MCU | RP2350B Dual M33 | RP2350B Dual M33 | RP2040 | RP2040 |
| Flash | 16 MB QSPI | 16 MB QSPI | 4 MB | 4 MB |
| ADC | 12-bit internal | 12-bit internal | MCP3208 SPI | MCP3208 SPI |
| MUXes | 6x HC4067 | 4x HC4067 | 5x MUX | 5x MUX |
| RGB LEDs | 94 (3 zones) | 64 per-key | 74 (2 zones) | 74 (2 zones) |
| Display | 0.85" 128x128 IPS (GC9107) | — | — | — |
| Touch | MPR121 Capacitive | — | — | — |
| Encoder | EC11 + 5-way joystick | EC11 | EC11 | EC11 |
| Wireless | — | nRF24L01+ 2.4GHz | nRF24L01+ 2.4GHz | nRF24L01+ 2.4GHz |
| Battery | — | LiPo + NTC | LiPo + TP4056 | LiPo + TP4056 |
| Multicore | Yes (Core 0 + Core 1) | No | No | No |
| SD Card | Yes (GIF storage) | — | — | — |
| SignalRGB | Yes | Yes | Yes | Yes |
| SOCD | 8 pairs, 3 modes | 8 pairs, 3 modes | 8 pairs, 3 modes | 8 pairs, 3 modes |
| Profiles | 10+10 | 10+10 | 10+10 | 10+10 |
| Key Modes | 9 | 9 | 9 | 9 |
Same footprint. Same firmware. Better sensing.
MDT TMR2617S-AAC — a TMR (Tunnel Magnetoresistance) sensor in the same SOT-23-3 package as our current Hall sensors. Drop-in replacement: same PCB footprint, same MUX+ADC scanning, same firmware — zero changes.
Evaluated TMR sensor landscape. Identified MDT TMR2617S-AAC as best candidate: Z-axis, single-ended analog output, SOT-23-3, <300uA, $0.02-0.04 bulk.
Order samples, test on breadboard with existing magnetic switches + RP2350B ADC. Compare noise floor, linearity, and range vs Hall sensors.
Verify SOT-23-3 footprint compatibility. Work with MDT on custom sensitivity programming for MARSVLT magnet geometry.
Establish supply chain (MDT direct or JLCPCB). Offer TMR variant alongside Hall. Advertise 0.01mm resolution and lower power.
Built in public — firmware, software, and hardware
# Build VLT firmware cd firmware/vlt/build cmake --build . -j4 # Build Saturn60 firmware cd firmware/saturn60/build cmake --build . -j4 # Flash via SWD debug probe openocd -f interface/cmsis-dap.cfg \ -f target/rp2350.cfg \ -c "program {VLT.elf} verify reset exit"