The UI board is now fully routed — every component has been placed, all nets connected, and the design passes DRC with no errors.

This was by far the most complex part of the Darśana hardware: 64 potentiometers, 32 key switches, 96 LEDs, four ADCs, two IO expanders, OLED, and all the SPI buses packed into a 4-layer board.

• +3V3_UI and +3V3_UI_A rails separated and thickened to 1 mm
• +5V_SYS → +5V_UI_LED isolated via 100 mΩ resistor
• VREF and ADC lines shielded with GND guards
• IOX inputs protected by RC (150 Ω + 1 nF) and 10 k pull-ups

After endless nights of routing and revising, the DRC finally came back clean.

Next step: a slow, quiet design review — then it’s time to generate Gerbers and send the first UI board to fabrication.