Fracanto Architecture #4 — Driver Layer

Driver Layer — peripheral hardware implementations

Five peripheral drivers implement the vtable interfaces for concrete hardware: ADS8866 (16-bit ADC via SPI with calibration), DAC8552 (dual 16-bit DAC via SPI with inverse calibration), PCM5102A (stereo audio DAC via I2S+DMA as an audio_ops_t implementation), an encoder driver (quadrature encoder and button via GPIO as a panel_ops_t implementation), and SSD1306 (OLED display via I2C with a standalone API). All drivers follow the dependency injection pattern.