Signals

The Signals screen (/signals) displays all signals configured for your layout and lets you control their aspect (red, yellow, or green). Signals reflect the state of track blocks and can be used to coordinate safe train movements during operating sessions.

Signal Cards

Each signal is rendered as a tonal card with a cyan theme. The card contains:

• Signal name as the card title (falling back to the signal ID if no name is set).
• Signal head -- a vertical column of three circular buttons representing the three aspects, displayed against a dark background to simulate a physical signal housing:
  • Red (top) -- the stop aspect. Shown as a bright red filled button when active, or a muted tonal red when inactive.
  • Yellow (middle) -- the caution/approach aspect. Shown as a bright amber filled button when active, or a muted tonal amber when inactive.
  • Green (bottom) -- the clear/proceed aspect. Shown as a bright green filled button when active, or a muted tonal green when inactive.

Toggling Aspects

Tap any of the three aspect buttons to change the signal:

• Tapping an inactive aspect activates it and deactivates any other active aspect. Only one aspect can be active at a time.
• Tapping the currently active aspect turns it off, setting the signal to a null (dark) state.

Aspect buttons are disabled if the signal does not have a pin number configured for that color. For example, if a two-aspect signal only has red and green pin numbers assigned, the yellow button will be disabled and non-interactive.

How Signals Work

Each signal in the system has up to three pin numbers (one per aspect) assigned to a connected device (Arduino or Pico W):

When you change a signal aspect:

1. The setSignalAspect function from the useSignals() composable writes the new aspect value to Firestore at layouts/{layoutId}/signals/{signalId}.
2. The DEJA.js server detects the Firestore change and sends the appropriate DCC-EX output commands (<Z pin state>) to turn the correct LED on and the others off.
3. If the signal uses common anode wiring, the pin logic is inverted automatically.

Filtering and Views

The Signals list supports filtering by:

• Device -- show only signals attached to a specific hardware device.
• Tags -- filter by user-defined tags.

Four view modes are available:

Signal Configuration

Signals are configured in the Cloud app, where you assign pin numbers, select the target device, and optionally set tags and descriptions. The Throttle app is used for monitoring and control during operations.

Empty State

If no signals are configured for the current layout, the page displays only the "Signals" heading. Signals must be added through the Cloud app before they appear here.