diff --git a/arduino/sketchDistanceSerial.ino b/arduino/sketchDistanceSerial.ino
index c721da1..b859879 100644
--- a/arduino/sketchDistanceSerial.ino
+++ b/arduino/sketchDistanceSerial.ino
@@ -6,8 +6,8 @@
 // Tested on 17 September 2019
 // ---------------------------------------------------------------- //
 
-#define echoPin 9 // attach pin D9 Arduino to pin Echo of HC-SR04
-#define trigPin 8 //attach pin D8 Arduino to pin Trig of HC-SR04
+#define echoPin 8 // attach pin D9 Arduino to pin Echo of HC-SR04
+#define trigPin 9 //attach pin D8 Arduino to pin Trig of HC-SR04
 
 // defines variables
 long duration; // variable for the duration of sound wave travel