1. Live KMK Macropad Simulator
XIAO
RP2040
SSD1306 128x32 I2C (0x3C)
> Ready: SW1..SW9 matrix active (COL2ROW 1N4148W)
Last Matrix Scan: None | Encoder Detent: 0 | Underglow: Hue 195 deg
2. 3D CAD Assembly & KiCad 8 PCB Inspector
3. XIAO RP2040 Wiring & Kit BOM
| XIAO Pin | Net Name | Connected Component |
|---|---|---|
| D0 / GPIO26 | COL0 | SW1, SW4, SW7 Col Bus |
| D1 / GPIO27 | COL1 | SW2, SW5, SW8 Col Bus |
| D2 / GPIO28 | COL2 | SW3, SW6, SW9 Col Bus |
| D3 / GPIO29 | ROW0 | D1..D3 Cathode Row 0 |
| D6 / GPIO0 | ROW1 | D4..D6 Cathode Row 1 |
| D7 / GPIO1 | ROW2 | D7..D9 Cathode Row 2 |
| D4 / GPIO6 | I2C_SDA | SSD1306 128x32 OLED SDA |
| D5 / GPIO7 | I2C_SCL | SSD1306 128x32 OLED SCL |
| D8 / D9 | ENC_A / B | EC11 Quadrature Phases |
| D10 / GPIO3 | ENC_SW | EC11 Push Switch + RGB |
Bill of Materials (Hackpad Kit)
| Ref | Qty | Part / Footprint |
|---|---|---|
| U1 | 1 | Seeed Studio XIAO RP2040 |
| SW1-SW9 | 9 | Cherry MX / Gateron 5-Pin Switches |
| D1-D9 | 9 | 1N4148W SOD-123 Switching Diodes |
| SW10 | 1 | Alps EC11 Rotary Encoder w/ Switch |
| U2 | 1 | 0.91" 128x32 SSD1306 I2C OLED |
| LED1-4 | 4 | SK6812 MINI-E Reverse-Mount RGB |
| K1-K9 | 9 | DSA 1u PBT Blank Keycaps |
| H1-H4 | 4 | M2x8mm Screws + M2x5mm Inserts |