diff --git a/nodes/prj.conf b/nodes/prj.conf
index 4210a15..55962f0 100644
--- a/nodes/prj.conf
+++ b/nodes/prj.conf
@@ -1,3 +1,2 @@
-CONFIG_GPIO=y
 CONFIG_SENSOR=y
-CONFIG_I2C=y
+CONFIG_BT=y
diff --git a/nodes/src/ble_advertiser.c b/nodes/src/ble_advertiser.c
index 46b857e..465ce09 100644
--- a/nodes/src/ble_advertiser.c
+++ b/nodes/src/ble_advertiser.c
@@ -1,14 +1,55 @@
 #include "ble_advertiser.h"
 
+static const int MS_ADV_UP = 500;   // time during which the advertising is active
+
+static const char BT_KEY_WINDOW = 0x01;
+static const char BT_KEY_HUMIDITY = 0x02;
+static const char BT_KEY_TEMP = 0x03;
+static const char BT_KEY_CO2_LVL = 0x04;
+
+// value size [B]
+static const char BT_VALUE_SIZE_WINDOW = 1;
+static const char BT_VALUE_SIZE_HUMIDITY = 1;
+static const char BT_VALUE_SIZE_TEMP = 2;
+static const char BT_VALUE_SIZE_CO2_LVL = 4;
+
+static const int BT_AD_DATA_INDEX_WINDOW = 1;
+static const int BT_AD_DATA_INDEX_HUMIDITY = 3;
+static const int BT_AD_DATA_INDEX_TEMP = 5;
+static const int BT_AD_DATA_INDEX_CO2_LVL = 8;
+
+// sum of all value size + size for all keys
+static const char BT_AD_TOTAL_SIZE = 
+    BT_VALUE_SIZE_WINDOW + BT_VALUE_SIZE_HUMIDITY + BT_VALUE_SIZE_TEMP + BT_VALUE_SIZE_CO2_LVL + 4;
+
+static uint8_t ad_data[] = {
+    BT_KEY_WINDOW, 0x00, BT_KEY_HUMIDITY, 0x00, BT_KEY_TEMP, 0x00, 0x00, BT_KEY_CO2_LVL, 0x00, 0x00, 0x00, 0x00
+};
+static const struct bt_data ad[] = {
+    BT_DATA(BT_DATA_MANUFACTURER_DATA, ad_data, BT_AD_TOTAL_SIZE),
+};
+
 enum error_code ble_init(){
-    return success;
+    return ((0 == bt_enable(NULL)) ? success : init_failed);
 }
 
 enum error_code ble_advertise(
-    int co2_lvl_value_ptr, 
-    int hygro_value_ptr, 
-    int thermo_value_ptr, 
-    enum window_status window_value_ptr
+    enum window_status window_value,
+    int hygro_value,
+    int thermo_value,
+    int co2_lvl_value
 ){
-    return success;
+    enum error_code ret = write_failed;
+    // set values here
+    ad_data[BT_AD_DATA_INDEX_WINDOW] = (uint8_t)(window_value == open ? 1 : 0);
+    ad_data[BT_AD_DATA_INDEX_HUMIDITY] = (uint8_t)(hygro_value);
+    ad_data[BT_AD_DATA_INDEX_TEMP] = (uint16_t)(thermo_value);
+    ad_data[BT_AD_DATA_INDEX_CO2_LVL] = (uint32_t)(co2_lvl_value);
+    if(0 == bt_le_adv_start(BT_LE_ADV_NCONN, ad, ARRAY_SIZE(ad), NULL, 0)){
+        k_msleep(MS_ADV_UP);
+        if(0 == bt_le_adv_stop()){
+            ret = success;
+        }else{}
+    }else{}
+    return ret;
 }
diff --git a/nodes/src/ble_advertiser.h b/nodes/src/ble_advertiser.h
index 5b8c329..f31a107 100644
--- a/nodes/src/ble_advertiser.h
+++ b/nodes/src/ble_advertiser.h
@@ -1,15 +1,19 @@
 #ifndef BLE_ADVERTISER_H
 #define BLE_ADVERTISER_H
 
+#include <zephyr/kernel.h>
+#include <zephyr/bluetooth/assigned_numbers.h>
+#include <zephyr/bluetooth/bluetooth.h>
+
 #include "error_code.h"
 #include "window_status.h"
 
 enum error_code ble_init();
 enum error_code ble_advertise(
-    int co2_lvl_value_ptr, 
-    int hygro_value_ptr, 
-    int thermo_value_ptr, 
-    enum window_status window_value_ptr
+    enum window_status window_value,
+    int hygro_value,
+    int thermo_value,
+    int co2_lvl_value
 );
 
 #endif //BLE_ADVERTISER_H
diff --git a/nodes/src/error_code.h b/nodes/src/error_code.h
index ea69fd1..ca53f8d 100644
--- a/nodes/src/error_code.h
+++ b/nodes/src/error_code.h
@@ -7,6 +7,7 @@ enum error_code{
     success = 0,
     init_failed,
     read_failed,
+    write_failed,
     error_unknown,
     error_code_last,    // iteration purpose
 };
diff --git a/nodes/src/hygrometer.c b/nodes/src/hygrometer.c
index 471ecfe..1706a65 100644
--- a/nodes/src/hygrometer.c
+++ b/nodes/src/hygrometer.c
@@ -14,7 +14,7 @@ enum error_code hygro_get_value(int* holder){
     enum error_code ret = read_failed;
     struct sensor_value humidity;
     if(sensor_channel_get(dev, SENSOR_CHAN_AMBIENT_TEMP, &humidity) >= 0){
-        *holder = sensor_value_to_deci(&humidity);
+        *holder = humidity.val1;    //taking only the integer part
         ret = success;
     }else{}
     return ret;