diff --git a/code_polisseur/code_polisseur.ino b/code_polisseur/code_polisseur.ino
index 83e38a6..86c372e 100644
--- a/code_polisseur/code_polisseur.ino
+++ b/code_polisseur/code_polisseur.ino
@@ -47,7 +47,8 @@ RotaryEncoder encoder(ROT_ENC_1, ROT_ENC_2);
 
 AccelStepper stepper(1, STEPPER_STEP, STEPPER_DIRECTION);
 
-EveryTimer timer;
+EveryTimer cntdwn;
+EveryTimer calc_dspl;
 
 //Global variables
 
@@ -74,42 +75,42 @@ static bool currBut = true;
 byte mode = 0;
 
 void countdown_callback() {
-  if (current_rpm != 0) {
+  if (current_rpm != 0) {   // if speed = 0 => pause countdown
     countdown--;
     if (countdown < 0) {
       countdown = 0;
-    } 
-    hours = countdown / 3600;
-    minutes = (countdown / 60) % 60;
-    seconds = countdown % 60;  
-    
-    // Update data to be displayed
-    if (mode == 0) {          // mode 0 = display speed
-      digitalWrite(SEVSEG_COLON, false);  
-      sevseg.setNumber(current_rpm);
-    } 
-    else if (mode == 1) {     // mode 1 = display countdown
-      //Blink colon each seconds
-      if (seconds % 2) {
-        digitalWrite(SEVSEG_COLON, true);
-      }
-      else {
-        digitalWrite(SEVSEG_COLON, false);
-      }
-      //Display HH:MM or MM:SS if there is less than 1h left
-      if (hours) {
-        sevseg.setNumber(100*hours+minutes);
-      } else {
-        sevseg.setNumber(100*minutes+seconds);
-      }
     }
-    Serial.println(countdown);
+    recalculate_HMS();
+    //Serial.println(countdown);
   }
   else {
     Serial.println("Pause");
   }
 }
 
+void calculate_display_callback() {
+  // Update data to be displayed
+  if (mode == 0) {          // mode 0 = display speed
+    digitalWrite(SEVSEG_COLON, false);  
+    sevseg.setNumber(current_rpm);
+  } 
+  else if (mode == 1) {     // mode 1 = display countdown
+    //Blink colon each seconds
+    if (countdown % 2) {
+      digitalWrite(SEVSEG_COLON, true);
+    }
+    else {
+      digitalWrite(SEVSEG_COLON, false);
+    }
+    //Display HH:MM or MM:SS if there is less than 1h left
+    if (hours) {
+      sevseg.setNumber(100*hours+minutes);
+    } else {
+      sevseg.setNumber(100*minutes+seconds);
+    }
+  }
+}
+
 void update_encoder() {
   static long currVal = 0;
   int multiplier = 10;
@@ -117,36 +118,42 @@ void update_encoder() {
   encoder.tick();
 
   long newVal = encoder.getPosition();
+  int dir = encoder.getDirection();
  
   if (currVal != newVal) {
     currVal = newVal;
-    if (mode == 0) {
+    if (mode == 0) {    // Mode 0 : speed setting
       if (current_rpm >= 500) {
-        multiplier = 100;
+        multiplier = 100;   // default : 1 encoder step = +/- 10 step/min
+                            // if speed > 500 : encoder step = +/- 100 step/min
       }
-      new_rpm += multiplier * encoder.getDirection();
-      if (new_rpm < STEPPER_MIN_SPEED) { 
+      new_rpm += multiplier * dir;
+      if (new_rpm < STEPPER_MIN_SPEED) {
         new_rpm = STEPPER_MIN_SPEED;
       }
-      if (new_rpm > STEPPER_MAX_SPEED) { 
+      if (new_rpm > STEPPER_MAX_SPEED) {
         new_rpm = STEPPER_MAX_SPEED;
       }
     }
-    if (mode == 1) {
-      multiplier = 60;
+    if (mode == 1) {    //mode 1 : countdown setting
+      multiplier = 60;  // default : 1 encoder step = +/- 1min
+                        // if countdown > 1h : encoder step = +/- 1h
       if (countdown >= 3600) {
         multiplier = 600;
       }
-      countdown += multiplier * encoder.getDirection();
+      countdown += multiplier * dir;
       if (countdown < 0) {
         countdown = 0;
       }
+      
+      // Max: 86400s = 1 day
       if (countdown >= 86400) {
         countdown = 86399;
       }
+      recalculate_HMS();
     }
     Serial.print("RPM: ");
-    Serial.print(current_rpm);
+    Serial.print(new_rpm);
     Serial.print(" | Countdown: ");
     Serial.println(countdown);
   }
@@ -174,8 +181,10 @@ void update_encoder() {
 }
 
 void update_stepper() {
+
+  //Update speend setting and ENABLE pin if new speed value
   if (new_rpm != current_rpm) {
-    new_rpm = current_rpm;
+    current_rpm = new_rpm;
     stepper.setSpeed(current_rpm);
     // Enable/Disable motor
     if (current_rpm == 0) {
@@ -186,12 +195,23 @@ void update_stepper() {
       stepper.enableOutputs();
       Serial.println("Stepper : On");
     }
-
-    //if Countdown = 0 => pause (no move but keep speed setting)
-    if (countdown != 0 and current_rpm != 0) {
-      stepper.runSpeed();
-    }
   }
+  //if Countdown = 0 => pause (no move but keep speed setting)
+  if (countdown != 0 and current_rpm != 0) {
+    //Serial.println("Run motor !");
+    stepper.runSpeed();
+  }
+}
+
+void recalculate_HMS() {
+  minutes = (countdown / 60) % 60;
+      if (countdown >= 3600) {
+        hours = countdown / 3600;  
+      }
+      else {
+        hours = 0;
+        seconds = countdown % 60;
+      }
 }
 
 void setup()
@@ -210,20 +230,21 @@ void setup()
   stepper.setAcceleration(STEPPER_ACCELERATION);
   stepper.setSpeed(0);  
 
-  timer.Every(1000, countdown_callback);
+  cntdwn.Every(1000, countdown_callback);
+  calc_dspl.Every(SEVSEG_REFRESH, calculate_display_callback);
 }
 
-void loop()
-{
+void loop() {
   update_encoder();
-  
-  //Update countdown
-  timer.Update();
 
   //Make the motor move
   update_stepper();
 
+  //Update countdown
+  cntdwn.Update();
+
   //refresh the 7-segment display
+  calc_dspl.Update();
   sevseg.refreshDisplay();
 }