diff --git a/controller_teensy/src/main.cpp b/controller_teensy/src/main.cpp
index 0de8403..744650c 100644
--- a/controller_teensy/src/main.cpp
+++ b/controller_teensy/src/main.cpp
@@ -23,7 +23,7 @@ unsigned long last_log_send=0;
 #define LOGMININTERVAL 20 //minimum interval (ms) to send logs
 #define LOGMAXINTERVAL 10000  //maximum time (ms) after which data is send
 
-#define WRITE_HEADER_TIME 1000
+#define WRITE_HEADER_TIME 400  //just before FEEDBACKRECEIVETIMEOUT, so header gets written before error comments
 bool log_header_written = false;
 
 
@@ -112,12 +112,12 @@ SerialCommand CommandFront;
 SerialCommand CommandRear;
 
 
-typedef struct{
+typedef struct{ //match this struct to hoverboard-firmware SerialFeedback struct in main.c
    uint16_t start;
    int16_t  cmd1;
    int16_t  cmd2;
-   int16_t  speedL_meas; //left speed is negative when driving forward
-   int16_t  speedR_meas; //right speed is positive when driving forward
+   int16_t  speedR_meas; //right speed is negatie when driving forward
+   int16_t  speedL_meas; //left speed is positive when driving forward
    int16_t  batVoltage;
    int16_t  boardTemp;
    int16_t  curL_DC; //negative values are current consumed. positive values mean generated current
@@ -130,8 +130,8 @@ SerialFeedback NewFeedbackFront;
 SerialFeedback FeedbackRear;
 SerialFeedback NewFeedbackRear;
 
-#define CURRENT_FILTER_SIZE 20 //latency is about CURRENT_FILTER_SIZE/2*MEASURE_INTERVAL (measure interval is defined by hoverboard controller)
-#define CURRENT_MEANVALUECOUNT 4 //0<= meanvaluecount < CURRENT_FILTER_SIZE/2. how many values will be used from sorted weight array from the center region. abour double this values reading are used
+#define CURRENT_FILTER_SIZE 40 //latency is about CURRENT_FILTER_SIZE/2*MEASURE_INTERVAL (measure interval is defined by hoverboard controller)
+#define CURRENT_MEANVALUECOUNT 10 //0<= meanvaluecount < CURRENT_FILTER_SIZE/2. how many values will be used from sorted weight array from the center region. abour double this values reading are used
 typedef struct{
   int16_t curL_DC[CURRENT_FILTER_SIZE] = {0}; //current will be inverted for this so positive value means consumed current
   int16_t curR_DC[CURRENT_FILTER_SIZE] = {0};
@@ -359,10 +359,10 @@ void writeLog(HardwareSerial &SerialRef, unsigned long time, MotorParameter &mpf
   SerialRef.print(mprear.filtered_curL,3); SerialRef.print(",");
   SerialRef.print(mprear.filtered_curR,3); SerialRef.print(",");
 
-  SerialRef.print(-fbfront.speedL_meas); SerialRef.print(","); //invert speed, because left wheels are negated
-  SerialRef.print(fbfront.speedR_meas); SerialRef.print(",");
-  SerialRef.print(-fbrear.speedL_meas); SerialRef.print(","); //invert speed, because left wheels are negated
-  SerialRef.print(fbrear.speedR_meas); SerialRef.print(",");
+  SerialRef.print(fbfront.speedL_meas); SerialRef.print(","); //invert speed, because left wheels are negated
+  SerialRef.print(-fbfront.speedR_meas); SerialRef.print(",");
+  SerialRef.print(fbrear.speedL_meas); SerialRef.print(","); //invert speed, because left wheels are negated
+  SerialRef.print(-fbrear.speedR_meas); SerialRef.print(",");
 
   SerialRef.print(fbfront.boardTemp/10.0); SerialRef.print(","); //in degC
   SerialRef.print(fbrear.boardTemp/10.0); SerialRef.print(","); //in degC
@@ -569,7 +569,7 @@ void readButtons() {
 
   if (button_start_state) { //pressed
     if ( (loopmillis> button_start_lastchange + LONG_PRESS_ARMING_TIME)) { //pressed long
-      if (throttle_pos<=0 && brake_pos<=0 && !armed) {  //brake or thottle not pressed
+      if (throttle_pos<=0 && brake_pos<=0 && controllers_connected && !armed) {  //brake or thottle not pressed, controllers connected
         armed=true; //arm if button pressed long enough
         writeLogComment(Serial1,loopmillis, "Armed by button");
       }