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Author: MaxwellDPS

cmd/rpi_exporter/main.go

@@ -41,10 +41,13 @@ func main() {
 				log.Println("Sense HAT initialized")
 				defer hat.Close()
 
-				// Clear LED matrix on startup
+				// Clear LED matrix on startup and set nav lights
 				if err := hat.ClearLEDs(); err != nil {
 					log.Printf("Warning: Failed to clear LEDs: %v", err)
 				}
+				if err := hat.SetNavLights(); err != nil {
+					log.Printf("Warning: Failed to set nav lights: %v", err)
+				}
 
 				if hat.HasColorSensor() {
 					log.Println("Color sensor detected (Sense HAT v2)")
@@ -62,9 +65,9 @@ func main() {
 	if *flagAddr != "" {
 		// Metrics endpoint
 		http.Handle("/metrics", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			// Flash LED on scrape
+			// Flash strobes on scrape
 			if hat != nil {
-				go hat.FlashLED(0, 0, 0, 255, 0, 100*time.Millisecond)
+				go hat.FlashStrobes(100 * time.Millisecond)
 			}
 			var buf bytes.Buffer
 			if err := prometheus.Write(&buf, cfg); err != nil {
@@ -118,11 +121,16 @@ func main() {
 
 			switch r.Method {
 			case http.MethodDelete:
-				// Clear all LEDs
+				// Clear all LEDs (except nav lights)
 				if err := hat.ClearLEDs(); err != nil {
 					http.Error(w, err.Error(), http.StatusInternalServerError)
 					return
 				}
+				// Restore nav lights
+				if err := hat.SetNavLights(); err != nil {
+					http.Error(w, err.Error(), http.StatusInternalServerError)
+					return
+				}
 				w.WriteHeader(http.StatusNoContent)
 
 			case http.MethodPost:
@@ -138,6 +146,11 @@ func main() {
 					http.Error(w, "invalid JSON: "+err.Error(), http.StatusBadRequest)
 					return
 				}
+				// Protect top row (strobes) and bottom row (nav lights)
+				if req.Y == 0 || req.Y == 7 {
+					http.Error(w, "top and bottom rows are reserved for nav/strobe lights", http.StatusForbidden)
+					return
+				}
 				if err := hat.SetPixel(req.X, req.Y, req.R, req.G, req.B); err != nil {
 					http.Error(w, err.Error(), http.StatusBadRequest)
 					return

pkg/sensehat/sensehat.go

@@ -712,6 +712,31 @@ func (s *SenseHat) FlashLED(x, y int, r, g, b uint8, duration time.Duration) err
 	return s.SetPixel(x, y, 0, 0, 0)
 }
 
+// SetNavLights turns on the navigation lights (red port, green starboard) on the bottom row.
+func (s *SenseHat) SetNavLights() error {
+	if err := s.SetPixel(0, 7, 255, 0, 0); err != nil { // Red - port (left)
+		return err
+	}
+	return s.SetPixel(7, 7, 0, 255, 0) // Green - starboard (right)
+}
+
+// FlashStrobes briefly flashes the strobe lights on the top corners.
+func (s *SenseHat) FlashStrobes(duration time.Duration) error {
+	// Turn on strobes
+	if err := s.SetPixel(0, 0, 255, 255, 255); err != nil {
+		return err
+	}
+	if err := s.SetPixel(7, 0, 255, 255, 255); err != nil {
+		return err
+	}
+	time.Sleep(duration)
+	// Turn off strobes
+	if err := s.SetPixel(0, 0, 0, 0, 0); err != nil {
+		return err
+	}
+	return s.SetPixel(7, 0, 0, 0, 0)
+}
+
 // PlaneAnimation animates a plane flying across the LED matrix with nav lights.
 func (s *SenseHat) PlaneAnimation(frameDelay time.Duration) error {
 	// Plane shape (relative pixels from nose position)