The full schematic for Darśana is now complete — and the Pico 2’s GPIO pins are completely exhausted.

Every single pin now has a dedicated role: ADC channels for 64 knobs, SPI buses for LEDs and OLED, chip selects for four ADCs and two I/O expanders, I²S for the DAC, and even the line and phones detection inputs.

There are simply no free pins left.

At the same time, the number of parameters I wanted to control kept growing.

Designing Darśana became a constant balance between expressive control and hardware limits — a reminder that constraint can drive creativity.

In parallel, the front-panel design reached its first complete layout.

The knob arrangement is now mostly fixed, giving a clear sense of how the instrument will feel in the hands.

Seeing the schematic and panel evolve together made the project finally start to feel real.

Next, I’ll carefully review the schematic again against all component datasheets, and then request an external design review before moving to PCB layout.

It’s the moment where ideas must prove themselves in actual copper and traces.