Design Log DEC 034 switch hardware refresh settings board toggle discrete rgb led ruggedized pm sw1 - thepinkmile/Enigma-NG GitHub Wiki

DEC-034 - Switch Hardware Refresh: Settings Board Toggle + Discrete RGB LED, Ruggedized PM SW1

  • Status: Decided
  • Date: 2026-04-16
  • Category: Electrical / HMI / Mechanical interface
  • Area: Settings Board; Power Module front-panel switchgear
  • Author: Izzyonstage & GitHub Copilot

Summary

Replace the old unified Marquardt rocker-switch assumption with two purpose-specific solutions: E-Switch 200-series toggle switches plus discrete RGB LEDs on the Settings Board, and the Adafruit 4660 rugged metal RGB latching switch for Power Module SW1.

Problem

The previous design direction forced the Settings Board and Power Module onto one shared switch family even though the two locations serve different aesthetic, mechanical, and service roles. The Settings Board benefits from classic toggle controls with separate indicators, while the Power Module benefits from a sealed, rugged metal power switch with a more robust panel interface and spade-terminal wiring.

Decision

  1. Settings Board switch selection: Use 200MSP1T2B4M2QE for the 10 configuration toggles (SW_B1[3:0], SW_B2[5:0]).
  2. Settings Board LED selection: Use WP154A4SEJ3VBDZGW/CA for all 12 Settings Board indicators (10 config-bit indicators + 2 source-status indicators).
    • Kingbright 5mm common-anode RGB through-hole LED
    • Full RGB operation is available under CM5 control
    • Separate red, green, and blue series resistors per switch allow colour balancing under nominal 5V operation
  3. Settings Board LED topology update: Change the indicator drive from the previous common-cathode / PNP sourcing concept to:
    • individual LED anode drive from U2 / U3
    • per-bank red / green / blue shared cathode rails
    • low-side BSS138 sink devices on each bank colour rail
  4. Power Module switch selection: Use Adafruit 4660 for SW1.
    • Latching rugged metal power switch
    • RGB ring illumination
    • 16mm panel cutout
    • 2.8mm pin terminals routed to PCB-mounted 2.8mm male spade tabs for serviceable harnessing

Rationale

  • The Settings Board now matches the machine's more period-correct control aesthetic better than a rocker-based panel.
  • Separate LEDs give more freedom over indicator placement and future panel detailing than integrated illuminated switches.
  • The Power Module switch benefits from a tougher sealed metal body and clearer power-switch identity than the previous shared-family concept.
  • Breaking the false BOM unification removes a mechanical compromise that was not buying any real electrical simplification.

Impact

  • Settings Board Design_Spec / Board_Layout: switch type, LED type, and LED driver polarity all change
  • Consolidated BOM: split the old shared rocker line into distinct Settings Board and Power Module entries
  • Power Module Design_Spec: SW1 selection and harnessing updated to the rugged metal switch
  • Copilot handoff / component tracking: the old Marquardt-all-13-switches assumption is retired