diff --git a/controller_teensy/include/display.h b/controller_teensy/include/display.h
index 65a0246..ea34fb8 100644
--- a/controller_teensy/include/display.h
+++ b/controller_teensy/include/display.h
@@ -318,7 +318,11 @@ void display_standingDisarmedDisplay(ESCSerialComm& escFront, ESCSerialComm& esc
   display.setFont();
   display.setCursor(0,0);
 
-  display.print(getLogFilename());
+  if (datalogging) {
+    display.print(getLogFilename());
+  }else{
+    display.print("LOG DISABLED");
+  }
     
   display.print(F(" ")); display.print(loopmillis/1000);
   display.print(F("s"));
diff --git a/controller_teensy/include/logging.h b/controller_teensy/include/logging.h
index 93c37db..6170732 100644
--- a/controller_teensy/include/logging.h
+++ b/controller_teensy/include/logging.h
@@ -7,6 +7,7 @@
 #include <SD.h> //Format sd cart with FAT or FAT16. FAT32 for >1GB Cards on Teensy4.1
 
 //#define SDCHIPSELECT 14
+boolean sdcard_available=false;
 boolean datalogging=true;
 String datalogging_filename="UNKNOWN.txt";
 
@@ -23,34 +24,46 @@ void serialCommandLoop();
 
 
 bool initLogging() {
-    Serial.print("Initializing SD card...");
-    // see if the card is present and can be initialized:
-    if (!SD.begin(BUILTIN_SDCARD)) {
-        Serial.println("Card failed, or not present");
-        display.println(F("SD Init Fail!")); display.display();
-        datalogging=false; //disable logging
-        delay(1000);
-        return false;
-    }else{
-        Serial.println("Card initialized.");
-        display.print(F("LOG=")); display.display();
-        if (datalogging){
-          int filenumber=0;
-          char buffer[6];
+  Serial.print("Datalogging is ");
+  if (datalogging) {
+    Serial.println("enabled");
+  }else{
+    Serial.println("disabled");
+  }
+  Serial.print("Initializing SD card...");
+  // see if the card is present and can be initialized:
+  if (!SD.begin(BUILTIN_SDCARD)) {
+      Serial.println("Card failed, or not present");
+      display.println(F("SD Init Fail!")); display.display();
+      sdcard_available=false; //disable logging
+      datalogging=false;
+      delay(1000);
+      return false;
+  }else{
+      sdcard_available=true;
+      Serial.println("Card initialized.");
+      display.print(F("LOG=")); display.display();
+    
+      int filenumber=0;
+      char buffer[6];
+      sprintf(buffer, "%04d", filenumber);
+      datalogging_filename="LOG_"+String(buffer)+".TXT";
+      while(SD.exists(datalogging_filename.c_str()) && filenumber<10000) {
+          //Serial.print(datalogging_filename); Serial.println(" exists");
+          filenumber++;
           sprintf(buffer, "%04d", filenumber);
           datalogging_filename="LOG_"+String(buffer)+".TXT";
-          while(SD.exists(datalogging_filename.c_str()) && filenumber<10000) {
-              //Serial.print(datalogging_filename); Serial.println(" exists");
-              filenumber++;
-              sprintf(buffer, "%04d", filenumber);
-              datalogging_filename="LOG_"+String(buffer)+".TXT";
 
-          }      
-          Serial.print(datalogging_filename); Serial.println(" is free");
-          display.print(datalogging_filename); display.println(); display.display();
-        }
-    }
-    return true;
+      }      
+      Serial.print(datalogging_filename); Serial.println(" is free");
+      display.print(datalogging_filename); 
+      if (!datalogging) { //datalogging is disabled during boot
+        display.print( "NO LOG");
+      }
+      display.println(); display.display();
+      
+  }
+  return true;
 }
 
 
@@ -58,7 +71,7 @@ void loggingLoop(unsigned long loopmillis,ESCSerialComm& escFront, ESCSerialComm
 
   static unsigned long last_datalogging_write=0;
   static boolean logging_headerWritten=false;
-  if (datalogging) {
+  if (datalogging && sdcard_available) {
     #define LOGGINGINTERVAL 100
     if (loopmillis-last_datalogging_write>LOGGINGINTERVAL)
     {
@@ -123,7 +136,7 @@ void loggingLoop(unsigned long loopmillis,ESCSerialComm& escFront, ESCSerialComm
 
 void writeLogComment(unsigned long time, String msg) {
     //SerialRef.print("#"); SerialRef.print(time/1000.0,3); SerialRef.print(","); SerialRef.print(msg); SerialRef.println();
-    if (datalogging) {
+    if (datalogging && sdcard_available) {
         File dataFile = SD.open(datalogging_filename.c_str(), FILE_WRITE);
 
         if (dataFile) { // if the file is available, write to it
@@ -156,6 +169,7 @@ bool loadTripSD()
     myFile.close();
     Serial.println("TripSD: time written");
   }else{
+    Serial.println("TripSD: could not open stats.txt");
     return false;
   }
 
@@ -198,7 +212,7 @@ bool loadTripSD()
 }
 
 void writeTrip(unsigned long loopmillis,ESCSerialComm& escFront, ESCSerialComm& escRear) {
-  if (datalogging) {
+  if (datalogging && sdcard_available) {
     File myFile = SD.open("stats.txt", FILE_WRITE);
     if (myFile) {
       myFile.print("trp=");
@@ -216,7 +230,7 @@ void writeTrip(unsigned long loopmillis,ESCSerialComm& escFront, ESCSerialComm&
 }
 
 void resetTrip() {
-  if (datalogging) {
+  if (datalogging && sdcard_available) {
     File myFile = SD.open("stats.txt", FILE_WRITE);
     if (myFile) {
       myFile.print("trp=");
diff --git a/controller_teensy/src/main.cpp b/controller_teensy/src/main.cpp
index c2825a3..678a005 100644
--- a/controller_teensy/src/main.cpp
+++ b/controller_teensy/src/main.cpp
@@ -69,11 +69,12 @@ void setup()
 
   Serial1.begin(SERIAL_LOG_BAUD); //TX1=1, RX1=0
 
-  //Serial2.begin(SERIAL_CONTROL_BAUD); //control, TX2=10, RX2=9
-  //Serial3.begin(SERIAL_CONTROL_BAUD); //control, TX3=8, RX3=7
-
   
   pinMode(PIN_PWRBUTTON, INPUT_PULLUP); //Pressed=High
+  if (!digitalRead(PIN_PWRBUTTON)) { //button is not pressed during startup means teensy is powered externally (usb)
+    datalogging=false; //disable logging when connected via usb to not clutter up sd card
+    Serial.println("PWRBUTTON not pressed. Logging disabled!");
+  }
 
   pinMode(PIN_LED_START, OUTPUT); //Active High
 
@@ -102,7 +103,7 @@ void setup()
 
   
   initResult=initLogging();
-  led_simpeProgress(2,initResult);
+  led_simpeProgress(2,(initResult ? (datalogging ? 1:2):0)); //0=sd card fail, 1=sd ok and logging, 2(warn)=sd ok and logging off
   
   
 
@@ -146,7 +147,7 @@ void setup()
   }
 
 
-  if (datalogging) { //sd init was successful
+  if (sdcard_available) { //sd init was successful
     initResult=loadTripSD();
   }else{
     initResult=false;