diff --git a/platformio.ini b/platformio.ini
index 0074e59..1995297 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -12,6 +12,7 @@
 platform = espressif32
 board = wt32-eth01
 framework = arduino
+board_build.f_cpu = 240000000L
 lib_deps = siwats/ESPMegaPROR3@^1.3.0
            knolleary/PubSubClient@^2.8
            ivanseidel/ArduinoThread@^2.1.1
diff --git a/src/espmega_iot_core.cpp b/src/espmega_iot_core.cpp
index 689ed12..587adad 100644
--- a/src/espmega_iot_core.cpp
+++ b/src/espmega_iot_core.cpp
@@ -159,6 +159,7 @@ void setup()
   lcd_send_command("boot_state.txt=\"IoT Core Initializing . . .\"");
   mqtt.setSocketTimeout(1000);
   eth.setTimeout(1);
+  mqtt.setCallback(&mqtt_callback);
   mqtt_connect();
   lcd_send_command("boot_state.txt=\"Threads Initializing . . .\"");
   thread_initialization();
@@ -518,18 +519,29 @@ void mqtt_subscribe()
   mqtt.subscribe(STATE_REQUEST_TOPIC);
 }
 
-void mqtt_callback(char* topic, char* payload, unsigned int length) {
+void mqtt_callback(char *topic, byte *payload, unsigned int length)
+{
   uint8_t topic_length = strlen(topic);
   char topic_trim[50];
-  strncpy(topic_trim, topic+topic_length, topic_length);
-  // PWM Callback
-  if((!strncmp(topic_trim,"/pwm/",5)) && !strncmp(topic_trim+7,"/set/state",10)) {
-    pwm_state_callback(topic_trim, topic_length,payload,length);
+  char payload_nt[length + 1];
+  memcpy(payload_nt, payload, length);
+  payload_nt[length] = NULL;
+  strncpy(topic_trim, topic + base_topic_length - 1, topic_length);
+  if ((!strncmp(topic_trim, "/pwm/", 5)) && !strncmp(topic_trim + 7, "/set/state", 10))
+  {
+    pwm_state_callback(topic_trim, topic_length, payload_nt, length);
   }
-  else if((!strncmp(topic_trim,"/pwm/",5)) && !strncmp(topic_trim+7,"/set/value",10)) {
-    pwm_value_callback(topic_trim, topic_length,payload,length);
+  else if ((!strncmp(topic_trim, "/pwm/", 5)) && !strncmp(topic_trim + 7, "/set/value", 10))
+  {
+    pwm_value_callback(topic_trim, topic_length, payload_nt, length);
+  } else if(!strcmp(topic,STATE_REQUEST_TOPIC)) {
+    state_request_callback();
   }
-  user_mqtt_callback(topic_trim,topic_length, payload, length);
+  else
+  {
+    ac_state_callback(topic, topic_length, payload_nt, length);
+  }
+  user_mqtt_callback(topic_trim, topic_length, payload_nt, length);
 }
 
 void thread_initialization()
@@ -548,22 +560,22 @@ void thread_initialization()
   user_timer_tick.setInterval(15000);
 }
 
-void pwm_state_callback(char* topic, uint8_t topic_length, char* payload, unsigned int payload_length)
+void pwm_state_callback(char *topic, uint8_t topic_length, char *payload, unsigned int payload_length)
 {
   int a = topic[5] - '0';
   int b = topic[6] - '0';
   int id = 10 * a + b;
-  if (!strcmp(payload,"on"))
+  if (!strcmp(payload, "on"))
   {
     pwm_set_state(id, true);
   }
-  else if (!strcmp(payload,"off"))
+  else if (!strcmp(payload, "off"))
   {
     pwm_set_state(id, false);
   }
 }
 
-void pwm_value_callback(char* topic, uint8_t topic_length, char* payload, unsigned int payload_length)
+void pwm_value_callback(char *topic, uint8_t topic_length, char *payload, unsigned int payload_length)
 {
   int a = topic[5] - '0';
   int b = topic[6] - '0';
@@ -629,7 +641,7 @@ void publish_pwm_state(int id)
     mqtt.publish(PWM_STATE_TOPIC, "off");
   }
   char temp[6];
-  itoa(value,temp,6);
+  itoa(value, temp, DEC);
   mqtt.publish(PWM_VALUE_TOPIC, temp);
 }
 
@@ -740,7 +752,7 @@ void publish_input_state(int id, int state)
   mqtt.publish(INPUTS_TOPIC, state ? "1" : "0");
 }
 
-void state_request_callback(String topic, String message)
+void state_request_callback()
 {
   publish_input_states();
   publish_pwm_states();
@@ -777,7 +789,7 @@ void publish_ac_state()
     break;
   }
   char temp[5];
-  itoa(ac_temperature,temp,DEC);
+  itoa(ac_temperature, temp, DEC);
   mqtt.publish(AC_TEMPERATURE_TOPIC, temp);
   switch (ac_fan_speed)
   {
@@ -794,49 +806,48 @@ void publish_ac_state()
     mqtt.publish(AC_FAN_TOPIC, "low");
     break;
   }
-  
 }
 
-void ac_state_callback(String topic, String message)
+void ac_state_callback(char *topic, uint8_t topic_length, char *payload, unsigned int payload_length)
 {
-  if (topic.compareTo(String(AC_SET_TEMPERATURE_TOPIC)) == 0)
+  if (!strcmp(topic, AC_SET_TEMPERATURE_TOPIC))
   {
-    int new_temp = message.toInt();
+    int new_temp = atoi(payload);
     if (new_temp >= AC_MIN_TEMPERATURE && new_temp <= AC_MAX_TEMPERATURE)
     {
       ac_set_state(ac_mode, new_temp, ac_fan_speed);
     }
   }
-  else if (topic.compareTo(String(AC_SET_MODE_TOPIC)) == 0)
+  else if (!strcmp(topic, AC_SET_MODE_TOPIC))
   {
-    if (message.compareTo("off") == 0)
+    if (!strcmp(payload, "off"))
     {
       ac_set_state(0, ac_temperature, ac_fan_speed);
     }
-    else if (message.compareTo("cool") == 0)
+    else if (!strcmp(payload, "cool"))
     {
       ac_set_state(1, ac_temperature, ac_fan_speed);
     }
-    else if (message.compareTo("fan_only") == 0)
+    else if (!strcmp(payload, "fan_only"))
     {
       ac_set_state(2, ac_temperature, ac_fan_speed);
     }
   }
-  else if (topic.compareTo(String(AC_SET_FAN_TOPIC)) == 0)
+  else if (!strcmp(topic, AC_SET_FAN_TOPIC))
   {
-    if (message.compareTo("auto") == 0)
+    if (!strcmp(payload, "auto"))
     {
       ac_set_state(ac_mode, ac_temperature, 0);
     }
-    else if (message.compareTo("low") == 0)
+    else if (!strcmp(payload, "low"))
     {
       ac_set_state(ac_mode, ac_temperature, 1);
     }
-    else if (message.compareTo("med") == 0)
+    else if (!strcmp(payload, "med"))
     {
       ac_set_state(ac_mode, ac_temperature, 2);
     }
-    else if (message.compareTo("high") == 0)
+    else if (!strcmp(payload, "high"))
     {
       ac_set_state(ac_mode, ac_temperature, 3);
     }
diff --git a/src/espmega_iot_core.hpp b/src/espmega_iot_core.hpp
index 1d24dab..42582ed 100644
--- a/src/espmega_iot_core.hpp
+++ b/src/espmega_iot_core.hpp
@@ -43,7 +43,7 @@ void mqtt_subscribe();
 void thread_initialization();
 void pwm_state_callback(char* topic, uint8_t topic_length, char* payload, unsigned int payload_length);
 void pwm_value_callback(char* topic, uint8_t topic_length, char* payload, unsigned int payload_length);
-void state_request_callback(String topic, String message);
+void state_request_callback();
 void io_begin();
 void ir_loop();
 
@@ -66,7 +66,7 @@ void publish_env_state();
 uint8_t ac_get_temperature();
 uint8_t ac_get_mode();
 uint8_t ac_get_fan_speed();
-void ac_state_callback(String topic, String message);
+void ac_state_callback(char* topic, uint8_t topic_length, char* payload, unsigned int payload_length);
 void ac_set_state(int mode, int temperature, int fan_speed);
 
 void publish_input_states();