diff --git a/src/patterns.py b/src/patterns.py
index 1567306..087b210 100644
--- a/src/patterns.py
+++ b/src/patterns.py
@@ -37,6 +37,7 @@ class Patterns(PatternsBase):
             "rainbow": self.rainbow,
             "pulse": self.pulse,
             "transition": self.transition,
+            "n_chase": self.n_chase,
         }
 
 
@@ -78,7 +79,7 @@ class Patterns(PatternsBase):
             return
         
         # Auto is True: run continuously
-        sleep_ms = max(1, int(self.delay / 5))
+        sleep_ms = max(1, int(self.delay))
         last_update = utime.ticks_ms()
         
         while self.running:
@@ -100,10 +101,10 @@ class Patterns(PatternsBase):
         self.running = True
         self.off()
         
-        # Get timing parameters with defaults if not set
-        attack_ms = getattr(self, 'n1', 200)  # Attack time in ms
-        hold_ms = getattr(self, 'n2', 200)    # Hold time in ms
-        decay_ms = getattr(self, 'n3', 200)   # Decay time in ms
+        # Get timing parameters, ensure non-negative
+        attack_ms = max(0, int(self.n1))  # Attack time in ms
+        hold_ms = max(0, int(self.n2))    # Hold time in ms
+        decay_ms = max(0, int(self.n3))   # Decay time in ms
         
         # Ensure we have at least one color
         if not self.colors:
@@ -269,5 +270,71 @@ class Patterns(PatternsBase):
             # Move to next color
             color_index = (color_index + 1) % len(self.colors)
         
+        self.running = False
+        self.stopped = True
+
+    def n_chase(self):
+        """N-chase pattern: n1 LEDs of color0, n2 LEDs of color1, repeating.
+        Moves by n3 on even steps, n4 on odd steps (n3/n4 can be positive or negative)"""
+        self.stopped = False
+        self.running = True
+        
+        if len(self.colors) < 2:
+            # Need at least 2 colors
+            self.running = False
+            self.stopped = True
+            return
+        
+        n1 = max(1, int(self.n1))  # LEDs of color 0
+        n2 = max(1, int(self.n2))  # LEDs of color 1
+        n3 = int(self.n3)  # Step movement on odd steps (can be negative)
+        n4 = int(self.n4)  # Step movement on even steps (can be negative)
+        
+        segment_length = n1 + n2
+        position = 0  # Current position offset
+        step_count = 0  # Track which step we're on
+        
+        color0 = self.apply_brightness(self.colors[0])
+        color1 = self.apply_brightness(self.colors[1])
+        
+        transition_duration = max(10, self.delay)
+        last_update = utime.ticks_ms()
+        
+        while self.running:
+            current_time = utime.ticks_ms()
+            if utime.ticks_diff(current_time, last_update) >= transition_duration:
+                # Clear all LEDs
+                self.n.fill((0, 0, 0))
+                
+                # Draw repeating pattern starting at position
+                for i in range(self.num_leds):
+                    # Calculate position in the repeating segment
+                    relative_pos = (i - position) % segment_length
+                    if relative_pos < 0:
+                        relative_pos = (relative_pos + segment_length) % segment_length
+                    
+                    # Determine which color based on position in segment
+                    if relative_pos < n1:
+                        self.n[i] = color0
+                    else:
+                        self.n[i] = color1
+                
+                self.n.write()
+                
+                # Move position by n3 or n4 on alternate steps
+                if step_count % 2 == 0:
+                    position = position + n3
+                else:
+                    position = position + n4
+                
+                # Wrap position to keep it reasonable
+                max_pos = self.num_leds + segment_length
+                position = position % max_pos
+                if position < 0:
+                    position += max_pos
+                
+                step_count += 1
+                last_update = current_time
+        
         self.running = False
         self.stopped = True
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