FMS Hub State Reader

Disclaimer: WIP and untested on 2026 hardware; validate on your field connection. Custom code built on WPILib APIs (not official WPILib sample).

Purpose: Prefer actual FMS hub status over timer; fall back to timer when data is missing.

Code (Java/WPILib)
Assumes Alliance data and DriverStation game-specific message carry hub status (example encoding).

public class HubStateSource {
  private final HubShiftTimer timer;

  public HubStateSource(HubShiftTimer timer) {
    this.timer = timer;
  }

  public HubShiftTimer.HubState getOurHub() {
    Optional<HubShiftTimer.HubState> fms = readFmsHub();
    return fms.orElse(timer.get().ourHub());
  }

  private Optional<HubShiftTimer.HubState> readFmsHub() {
    String msg = DriverStation.getGameSpecificMessage();
    if (msg == null || msg.isEmpty()) return Optional.empty();
    // Example: first char 'A' = our hub active, 'I' = inactive
    char c = msg.charAt(0);
    if (c == 'A') return Optional.of(HubShiftTimer.HubState.ACTIVE);
    if (c == 'I') return Optional.of(HubShiftTimer.HubState.INACTIVE);
    return Optional.empty();
  }
}

How to test

• Sim: set DriverStation.simulateGameSpecificMessage and confirm state changes.
• Field: compare timer vs. FMS-reported hub status; prefer FMS when present.

Pitfalls

• Encoding of hub state in FMS may differ; update parsing accordingly.