diff --git a/controller/mixercontroller_w5100/mixercontroller_w5100.ino b/controller/mixercontroller_w5100/mixercontroller_w5100.ino
index cf2b410..d3772a4 100644
--- a/controller/mixercontroller_w5100/mixercontroller_w5100.ino
+++ b/controller/mixercontroller_w5100/mixercontroller_w5100.ino
@@ -25,9 +25,9 @@ long last_serialdebug=0;
 #define INTERVAL_SERIALDEBUG 200
 
 //Inputs
-#define PIN_BUTTON 9
-#define PIN_ENCA 7
-#define PIN_ENCB 8
+#define PIN_BUTTON 9 //D9 = PB1
+#define PIN_ENCA 7 //D7 = PD7
+#define PIN_ENCB 8 //D8 = PB0
 #define BUTTON_RELEASE_DEBOUNCE 100 //minimum time after button release to reenable triggering
 
 boolean button_flag=false; //true if button pressed
@@ -36,9 +36,9 @@ long last_button_released=0; //last time button has been released (for debounce)
 
 //Shift Register 595
 //connections: https://www.arduino.cc/en/tutorial/ShiftOut
-#define SRLATCH 4 
-#define SRCLOCK 5
-#define SRDATA 6
+#define SRLATCH 4 //D4 = PD4
+#define SRCLOCK 5 //D5 = PD5
+#define SRDATA 6 //D6 = PD6
 uint16_t srbits=0;
 
 #include <Encoder.h>
@@ -49,7 +49,7 @@ float encoderMultiplier=4.0;
 #define SRPIN_MOTOR_IN1 1 //L293(pin2) Motor IN1
 #define SRPIN_MOTOR_IN2 2 //L293(pin7) Motor IN2
 
-#define PIN_POT A0 //reference potentiometer wiper
+#define PIN_POT A0 //A0 = PC0, reference potentiometer wiper
 #define DEADZONE_POTI 5 //maximum allowed error. stop when reached this zone
 #define POT_MIN 10 //minimum value pot can reach
 #define POT_MAX 1010 //maximum value pot can reach
@@ -80,9 +80,6 @@ uint8_t error=0;
 #define MOTORDIDNOTTURN 1
 
 void setup() {
-  pinMode(LED_BUILTIN, OUTPUT);
-  digitalWrite(LED_BUILTIN,HIGH);
-
   pinMode(PIN_BUTTON,INPUT_PULLUP);
 
   pinMode(PIN_POT,INPUT);
@@ -208,7 +205,7 @@ void loop() {
   if (error==0){ //no errors
       
     if (!poti_reachedposition && abs(poti_read-poti_set)>DEADZONE_POTI){ //error too high
-      digitalWrite(LED_BUILTIN,HIGH);
+      
       if (poti_read-poti_set < 0){
         MOTOR_LEFT();
       }else{
@@ -224,7 +221,6 @@ void loop() {
       Serial.print(" vel=");
       Serial.println();
       poti_reachedposition=true; //position reached
-      digitalWrite(LED_BUILTIN,LOW);
     }
   
     
@@ -292,6 +288,7 @@ void sendData() {
 }
 
 void callback(char* topic, byte* payload, unsigned int length) {
+  payload[length] = '\0'; //add end of string character
   Serial.print("Message arrived [");
   Serial.print(topic);
   Serial.print("] ");//MQTT_BROKER
@@ -307,6 +304,16 @@ void callback(char* topic, byte* payload, unsigned int length) {
   
   if (strncmp((const char*)topic, "audiomixer/main/volume/set",sizeof(topic)) == 0) {
     //Serial.println("republish");
+    
+    String s = String((char*)payload);
+    Serial.print("Stringreceived=");
+    Serial.println(s);
+    float _floatvalue = s.toFloat();
+    Serial.print("setvalue=");
+    Serial.println(_floatvalue);
+    
+    poti_set=constrain(map(_floatvalue,0.0,100.0,POT_MIN,POT_MAX),POT_MIN,POT_MAX); //set new poti position
+    poti_reachedposition=false; //aim for new position
     mqttClient.publish("audiomixer/main/volume", payload, length );
   }