diff --git a/INSTALL.md b/INSTALL.md
index 48137fa..3861e95 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -1,5 +1,9 @@
-<h2>Installation Guide for PlatformIO</h2>
+<h2>Installation Guide using PlatformIO</h2>
 <br>
+1. Clone all files of the respository to your local working directory<br>
+2. Install the missing libraries<br>
+There are two possibilities - either using the Library Manager of PlatformIO or the command line tool:<br>
+<h3>1. Built-In Liabrary Manager</h3>
 Press the PlatformIO HOME Button to enter the Home Screen and there the Libraries Button to add missing libraries:<br>
 <img src="img/img1.jpg" width="480"><br>
 Search and install the following libaries:<br>
@@ -15,5 +19,17 @@ Search and install the following libaries:<br>
 <li>DallasTemperature</li>
 </ul>
 <br>
+<h3>2. Command Line Tool</h3>
+use the following commands<br>
+platformio lib install "RadioHead"<br>
+platformio lib install "TinyGPSPlus"<br>
+platformio lib install "DHT sensor library for ESPx"<br>
+platformio lib install "Adafruit SSD1306"<br>
+platformio lib install "Adafruit GFX Library"<br>
+platformio lib install "AXP202X_Library"<br>
+platformio lib install "Adafruit Unified Sensor"<br>
+platformio lib install "OneWire"<br>
+platformio lib install "DallasTemperature"<br>
+<br>
 Check that the platformio.ini is available as it holds the board type for PlatformIO.<br>
 After pressing the check mark the code will be compiled, after pressing the arrow it will be compiled and uploaded to a connected TTGO.<br>
diff --git a/src/TTGO_T-Beam_LoRa_APRS.ino b/src/TTGO_T-Beam_LoRa_APRS.ino
index f7fbdb0..6e48997 100644
--- a/src/TTGO_T-Beam_LoRa_APRS.ino
+++ b/src/TTGO_T-Beam_LoRa_APRS.ino
@@ -525,9 +525,22 @@ void loop() {
     ++point_avg_course;
     if (point_avg_course>2) {
       point_avg_course=0;
-      new_course = (average_course[0]+average_course[1]+average_course[2])/3;
-      if (abs(new_course-old_course)>=30) {
-        nextTX = 0;
+      // new_course = (average_course[0]+average_course[1]+average_course[2])/3;
+      new_course = atan ((sin(average_course[0])+sin(average_course[1])+sin(average_course[2]))/(cos(average_course[0])+cos(average_course[1])+cos(average_course[2])));
+      if ((old_course < 30) && (new_course > 330)) {
+        if (abs(new_course-old_course-360)>=30) {
+          nextTX = 0;
+        }
+      } else {
+        if ((old_course > 330) && (new_course < 30)) {
+          if (abs(new_course-old_course+360)>=30) {
+            nextTX = 0;
+          }
+        } else {
+          if (abs(new_course-old_course)>=30) {
+            nextTX = 0;
+          }
+        }
       }
       old_course = new_course;
     }