Micropad

3×3 MicroPad for ESP32-S3 (Waveshare ESP32-S3 Zero)

Compact and fast macropad with 9 keys, volume knob (rotary) and two layers (Numbers & Shortcuts). The device functions as a USB-HID keyboard + Consumer Control (media/volume) – plug-and-play in Windows, macOS, and Linux. A third mode (Applications) is reserved for future features.

Repo (code, schematic, config & optional 3D files):

https://github.com/George3235/Makro_Pad 

Highlights

• 9× MX keys (1U) in a classic 3×3 matrix
• Two layers (switched by double-clicking the encoder button)
  • Numbers: sends characters 1–9 according to the matrix

  • Shortcuts (Windows by default):

     

    Copy                   Paste                       Cut 

    Undo                  Select All                 New Tab 

    Screenshot        Rename(F2)           Play/Pause 

  • Easy to change for macOS/Linux in the code
• Rotary encoder (KY-040/EC11):
  • Turn right/left → Volume + / Volume −
  • Click: Mute/Unmute
  • Double-click: switch layers (Numbers ↔ Shortcuts)
  • Long press: reserved for Applications
• USB-HID & Consumer Control: directly supported by the OS
• Open and modifiable: simple C++/Arduino code with clear folders and comments
• (Optional) OLED display (SSD1306, I²C) and/or NeoPixel underglow – if you want to add it

Bill of Materials (BOM)

Electronics

• 1× Waveshare ESP32-S3 Zero (USB-C, built-in USB-HID support via TinyUSB)
• 9× MX-compatible switches (Cherry-type) + 9× keycaps (1U)
• 9× signal diodes (e.g., 1N4148) for the matrix
• 1× Rotary encoder (KY-040/EC11) + 1× knob (6 mm D-shaft)
• Flat cable/single wire (26–28 AWG), pin header, optional dupont
• USB-C cable

(Optional)

• 1× OLED 0.96" SSD1306 (I²C)
• NeoPixel/WS2812B (e.g., small ring or strip)
• Resistor for LED (if you add your own LEDs)

Mechanics & assembly

• 3D-printed parts: Top plate, Bottom case, Encoder spacer, Knob
  – key switch holes 14×14 mm (provides a good fit for MX switches)
• Screws & threaded inserts (e.g., M3 heat-set inserts + M3×6–8 mm screws)

3D Printing

• Material: PLA or PETG
• Layer height: 0.2 mm (0.16–0.28 mm works)
• Infill: 15–25 %
• Perimeters: ≥3 for stable top plate
• Supports:
  • Top plate: usually without supports
  • Bottom case: supports at USB cutout if your chassis has an opening
• Orientation: print the top plate with the top side up; the bottom case with the bottom side down
• Fit: 14×14 mm for MX switches usually provides a good press-fit. Adjust as needed.

Upload STL/STEP to the MakerWorld project: Topplate.stl, CaseBottom.stl, Knob.stl (filename optional).

Connections (overview)

• Encoder (default in code):
  • DT → GP6
  • CLK → GP7
  • SW → GP8 (internal pull-up enabled in code)
• Key matrix: rows/columns are defined in Config.h in the repo.
  Connect according to that table (diodes in series per button, all keys in a 3×3 matrix).

Tip: If the encoder “goes backward,” swap DT and CLK.

Firmware

You can build in Arduino IDE or PlatformIO.

Arduino IDE (simple)

1. Install ESP32 support (Boards Manager → esp32 by Espressif).
2. Select board: ESP32S3 Dev Module or Waveshare ESP32-S3 Zero (if available).
3. In Tools:
   • Enable USB CDC on boot
   • Enable TinyUSB (HID) if the option is available
4. Clone/copy the project from the repo and open the main sketch.
5. Libraries (only if needed):
   • Adafruit NeoPixel (if you use underglow)
   • Adafruit SSD1306 + Adafruit GFX (if you use OLED)
6. Compile & upload. In case of problems: hold BOOT while pressing RESET to enter the bootloader.

PlatformIO (advanced/consistent)

The repo contains a PlatformIO config. Typically:

[env:esp32s3zero] platform = espressif32 board = esp32-s3-devkitc-1 framework = arduino 

Build and flash via pio run -t upload.

Usage

• Connect via USB-C → the device appears as a keyboard (HID).
• Encoder:
  • Turn: volume up/down
  • Click: mute/unmute
  • Double-click: switch layers
  • Long press: (future) Applications

• Numbers layer: sends 1–9 according to the layout:

   

  7  8  9

  4  5  6

  1  2  3

• Shortcuts layer (default Windows):

   

  Copy                   Paste                         Cut 

  Undo                  Select All                   New Tab 

  Screenshot        Rename(F2)              Play/Pause 

Customize

• Keymaps & layers: open Shortcuts.h / Config.h in the repo and replace combinations (e.g., for macOS Cmd instead of Ctrl).
• Encoder behavior: change functions for onClick, onDoubleClick, onLongPress.
• Third layer (Applications): ready hook in StateMachine – add your app launchers, window management, etc.
• OLED/NeoPixel: activate and connect according to the comments in the code if you want to use these.

Troubleshooting

• No COM port / Port busy: disconnect/reconnect, try another cable/port, close programs that lock the port (serial monitor), try BOOT+RESET sequence.
• Wrong encoder direction: swap DT ↔ CLK.
• Key spams / doesn't work: check diode direction and matrix wiring according to Config.h.