Complete working firmware including:
- CMakeLists.txt for Pico SDK build
- SSD1306 OLED driver (128x32, I2C)
- High-resolution latency measurement using hardware timer
- Debounced button with short/long press detection
- Three modes: Single, Continuous, Stats
- USB serial debugging output
Includes 8x8 font with numbers and letters for display.
Schematic includes:
- Power section: SS14 reverse protection, AMS1117-3.3 LDO
- RP2040-Zero and OLED module headers
- Trigger output: 74LVC1G17 Schmitt buffer
- Return input: voltage divider, BAT54 clamps, MCP6001 buffer
- Button with pull-up, power LED
BOM updated with correct parts and LCSC numbers.
ASCII schematic reference in hardware/kicad/README.md.
florian.berthold