diff --git a/main/config.hpp b/main/config.hpp
index 2c82a07..40bbe47 100644
--- a/main/config.hpp
+++ b/main/config.hpp
@@ -55,6 +55,9 @@ extern "C" {
 
 
 
+//=============================
+//======= configuration =======
+//=============================
 //--------------------------
 //----- display config -----
 //--------------------------
@@ -79,11 +82,20 @@ extern "C" {
 //--------------------------
 //------ calibration -------
 //--------------------------
-//use encoder test for calibration and calculate STEPS_PER_METER
-//#define ENCODER_TEST //show encoder count instead of converted meters
+//enable mode  encoder test for calibration
+//if defined, displays always show length and steps instead of the normal messages
+//#define ENCODER_TEST
+
+//steps per meter
 #define STEPS_PER_METER 2127 //roll-v3-gummi-86.6mm - d=89.8mm
-//#define MEASURING_ROLL_DIAMETER 86.6 //roll v3 large
-//#define PI 3.14159265358979323846
+
+//millimetres added to target length
+//to ensure that length does not fall short when spool slightly rotates back after stop
+#define TARGET_LENGTH_OFFSET 20
+
+//millimetres lengthNow can be below lengthTarget to still stay in target_reached state
+#define TARGET_REACHED_TOLERANCE 5
+
 
 
 
diff --git a/main/control.cpp b/main/control.cpp
index 3049d19..85bb2ec 100644
--- a/main/control.cpp
+++ b/main/control.cpp
@@ -43,7 +43,7 @@ QueueHandle_t encoder_queue = NULL; //encoder event queue
 rotary_encoder_state_t encoderState;
 
 int lengthNow = 0; //length measured in mm
-int lengthTarget = 3000; //target length in mm
+int lengthTarget = 5000; //default target length in mm
 int lengthRemaining = 0; //(target - now) length needed for reaching the target
 int potiRead = 0; //voltage read from adc
 uint32_t timestamp_motorStarted = 0; //timestamp winding started
@@ -312,7 +312,7 @@ void task_control(void *pvParameter)
         //--------- control ---------
         //---------------------------
         //calculate length difference
-        lengthRemaining = lengthTarget - lengthNow;
+        lengthRemaining = lengthTarget - lengthNow + TARGET_LENGTH_OFFSET;
 
         //--- statemachine ---
         switch (controlState) {
@@ -349,7 +349,7 @@ void task_control(void *pvParameter)
             case systemState_t::TARGET_REACHED:
                 vfd_setState(false);
                 //switch to counting state when no longer at or above target length
-                if ( lengthRemaining > 10 ) { //FIXME: require reset switch to be able to restart? or evaluate a tolerance here?
+                if ( lengthNow < lengthTarget - TARGET_REACHED_TOLERANCE ) {
                     changeState(systemState_t::COUNTING);
                 }
                 //switch initiate countdown to auto-cut