Updated Add own functionality (markdown)

Add-own-functionality.md

@@ -22,4 +22,21 @@ col[1] | byte (0-255) | Green color value
 col[2] | byte (0-255) | Blue color value
 white | byte (0-255) | White color value
 
-After updating the color, you must call the `colorUpdated(int)` method. If you want to send a notification with the new color to other ESPs, use `colorUpdated(1)`, otherwise `colorUpdated(5)`.
+After updating the color, you must call the `colorUpdated(int)` method. If you want to send a notification with the new color to other ESPs, use `colorUpdated(1)`, otherwise `colorUpdated(5)`.
+
+### Timing
+
+If you'd just like a simple modification that requires timing (like sending a request every 2 seconds), please **never** use the `delay()` function in your `userLoop()`! It will block everything else and WLED will become unresponsive and effects won't work! Instead, try this instead:
+```
+long lastTime;
+int delayMs = 2000; //we want to do something every 2 seconds
+
+void userLoop()
+{
+  if (millis()-lastTime > delayMs)
+  {
+    lastTime = millis();
+    //do something you want to do every 2 seconds
+  }
+}
+```