Add patterns package.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/patterns/rainbow.py

@@ -0,0 +1,51 @@
+import utime
+
+
+class Rainbow:
+    def __init__(self, driver):
+        self.driver = driver
+
+    def _wheel(self, pos):
+        if pos < 85:
+            return (pos * 3, 255 - pos * 3, 0)
+        elif pos < 170:
+            pos -= 85
+            return (255 - pos * 3, 0, pos * 3)
+        else:
+            pos -= 170
+            return (0, pos * 3, 255 - pos * 3)
+
+    def run(self, preset):
+        step = self.driver.step % 256
+        step_amount = max(1, int(preset.n1))  # n1 controls step increment
+
+        # If auto is False, run a single step and then stop
+        if not preset.a:
+            for i in range(self.driver.num_leds):
+                rc_index = (i * 256 // self.driver.num_leds) + step
+                self.driver.n[i] = self.driver.apply_brightness(self._wheel(rc_index & 255), preset.b)
+            self.driver.n.write()
+            # Increment step by n1 for next manual call
+            self.driver.step = (step + step_amount) % 256
+            # Allow tick() to advance the generator once
+            yield
+            return
+
+        last_update = utime.ticks_ms()
+
+        while True:
+            current_time = utime.ticks_ms()
+            sleep_ms = max(1, int(preset.d))  # Get delay from preset
+            if utime.ticks_diff(current_time, last_update) >= sleep_ms:
+                for i in range(self.driver.num_leds):
+                    rc_index = (i * 256 // self.driver.num_leds) + step
+                    self.driver.n[i] = self.driver.apply_brightness(
+                        self._wheel(rc_index & 255),
+                        preset.b,
+                    )
+                self.driver.n.write()
+                step = (step + step_amount) % 256
+                self.driver.step = step
+                last_update = current_time
+            # Yield once per tick so other logic can run
+            yield