diff --git a/.vscode/settings.json b/.vscode/settings.json
index 0ecacf6..5bb08ba 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -7,6 +7,12 @@
 		"log.h": "c",
 		"mlx90614.h": "c",
 		"sensor.h": "c",
-		"sht4x.h": "c"
-	}
+		"sht4x.h": "c",
+		"array": "c",
+		"string_view": "c",
+		"initializer_list": "c",
+		"stm32-pinctrl-common.h": "c",
+		"printk.h": "c"
+	},
+	"cmake.sourceDirectory": "C:/Users/xlemmingx/Documents/PlatformIO/Projects/embedded_raumsenor_lorawan/zephyr"
 }
\ No newline at end of file
diff --git a/src/gpio.c b/src/gpio.c
new file mode 100644
index 0000000..c67f762
--- /dev/null
+++ b/src/gpio.c
@@ -0,0 +1,50 @@
+#include <gpio.h>
+
+#include <zephyr/kernel.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/logging/log.h>
+
+LOG_MODULE_REGISTER(gpio_relais);
+
+#if !DT_NODE_EXISTS(DT_NODELABEL(load_switch))
+#error "Overlay for power output node not properly defined."
+#endif
+
+static const struct gpio_dt_spec load_switch =
+	GPIO_DT_SPEC_GET_OR(DT_NODELABEL(load_switch), gpios, {0});
+
+void init_gpio()
+{
+	int err;
+
+	if (!gpio_is_ready_dt(&load_switch))
+	{
+		LOG_ERR("The load switch pin GPIO port is not ready.\n");
+		return 0;
+	}
+
+	LOG_INF("Initializing pin with inactive level.\n");
+
+	err = gpio_pin_configure_dt(&load_switch, GPIO_OUTPUT_INACTIVE);
+	if (err != 0)
+	{
+		LOG_ERR("Configuring GPIO pin failed: %d\n", err);
+		return 0;
+	}
+	/* Make sure relais is switched off */
+	set_relais_state(false);
+}
+
+void set_relais_state(bool state)
+{
+	int err = gpio_pin_set_dt(&load_switch, state);
+	if (err != 0)
+	{
+		LOG_ERR("Setting GPIO pin level failed: %d\n", err);
+	}
+}
+
+uint8_t get_relais_state()
+{
+	return (uint8_t)gpio_pin_get_dt(&load_switch);
+}
\ No newline at end of file
diff --git a/src/gpio.h b/src/gpio.h
new file mode 100644
index 0000000..af4e732
--- /dev/null
+++ b/src/gpio.h
@@ -0,0 +1,7 @@
+#include <zephyr/kernel.h>
+
+void init_gpio();
+
+void set_relais_state(bool state);
+
+uint8_t get_relais_state();
\ No newline at end of file
diff --git a/src/lora/lorawan.c b/src/lora/lorawan.c
index 0c34025..6e3253f 100644
--- a/src/lora/lorawan.c
+++ b/src/lora/lorawan.c
@@ -1,39 +1,52 @@
-#include <zephyr/kernel.h>
-#include <zephyr/lorawan/lorawan.h>
 #include <zephyr/logging/log.h>
+#include <zephyr/settings/settings.h>
+#include <zephyr/random/random.h>
+#include <zephyr/sys/printk.h>
+#include <zephyr/sys/util.h>
 
 #include <lora/lorawan.h>
+#include <gpio.h>
 
-/*
-	TODO:
-		- DEV NONCE in non volatile memory and increase
-		- format packets
-		- send: check if still in network
-		- downlink callback
+#define SETTINGS_KEY "LORAWAN_DEV_NONCE"
 
+LOG_MODULE_REGISTER(lorawan_class_a);
 
-	// Build payload byte array
-	uint8_t uplinkPayload[6];
-	uplinkPayload[0] = uint8_t (int(temp_room_mlx));
-	uplinkPayload[1] = uint8_t (int((temp_room_mlx-int(temp_room_mlx)*100)));    // See notes for high/lowByte functions
-	uplinkPayload[2] = uint8_t (int(temp_floor));
-	uplinkPayload[3] = uint8_t (int((temp_floor-int(temp_floor)*100)));    // See notes for high/lowByte functions
-	uplinkPayload[4] = uint8_t (int(humidity));
-	uplinkPayload[5] = uint8_t (relaisstate);    // See notes for high/lowByte functions
-*/
+extern bool relais_state;
+const static struct device *lora_dev;
+static struct lorawan_join_config join_cfg;
+static uint8_t app_key[] = LORAWAN_APP_KEY;
 
-const struct device *lora_dev;
-struct lorawan_join_config join_cfg;
-uint8_t dev_eui[] = LORAWAN_DEV_EUI;
-uint8_t join_eui[] = LORAWAN_JOIN_EUI;
-uint8_t app_key[] = LORAWAN_APP_KEY;
+static void dl_callback(uint8_t port, uint8_t flags, int16_t rssi, int8_t snr, uint8_t len,
+						const uint8_t *hex_data)
+{
+	LOG_INF("Port %d, Pending %d, RSSI %ddB, SNR %ddBm, Len: %d, Time %d", port,
+			flags & LORAWAN_DATA_PENDING, rssi, snr, len, !!(flags & LORAWAN_TIME_UPDATED));
+	if (hex_data)
+	{
+		LOG_HEXDUMP_INF(hex_data, len, "Payload: ");
+	}
 
-void init_lorawan() {
-	int ret;
+	/* Could be moved in a separate thread so we only have to set the variable here */
+	if (len > 3 && hex_data[0] == 'r' && hex_data[1] == '1')
+	{
+		uint8_t relais_value = hex_data[3];
+		LOG_INF("Received relais1 state change: %d", relais_value);
+		if (get_relais_state() != relais_value)
+		{
+			set_relais_state(relais_value);
+			LOG_INF("Set relais 1 value");
+		}
+		relais_state = relais_value;
+	}
+}
 
-	struct lorawan_downlink_cb downlink_cb = {
-		.port = LW_RECV_PORT_ANY,
-		.cb = dl_callback};
+struct lorawan_downlink_cb downlink_cb = {
+	.port = LW_RECV_PORT_ANY,
+	.cb = dl_callback};
+
+void init_lorawan()
+{
+	int err;
 
 	lora_dev = DEVICE_DT_GET(DT_ALIAS(lora0));
 	if (!device_is_ready(lora_dev))
@@ -42,10 +55,10 @@ void init_lorawan() {
 		return 0;
 	}
 
-	ret = lorawan_start();
-	if (ret < 0)
+	err = lorawan_start();
+	if (err < 0)
 	{
-		LOG_ERR("lorawan_start failed: %d", ret);
+		LOG_ERR("lorawan_start failed: %d", err);
 		return 0;
 	}
 	else
@@ -54,70 +67,66 @@ void init_lorawan() {
 	}
 
 	lorawan_register_downlink_callback(&downlink_cb);
-	lorawan_register_dr_changed_callback(lorwan_datarate_changed);
 
 	join_cfg.mode = LORAWAN_ACT_OTAA;
-	join_cfg.dev_eui = dev_eui;
-	join_cfg.otaa.join_eui = join_eui;
 	join_cfg.otaa.app_key = app_key;
-	join_cfg.otaa.nwk_key = app_key;
-	join_cfg.otaa.dev_nonce = 14u;	// TODO
+	join_cfg.otaa.dev_nonce = sys_rand16_get();
 }
 
-void join_network_otaa() {
-	int8_t status = -1;
-	while (lorawan_join(&join_cfg) < 0) {
+void join_network_otaa()
+{
+	int8_t ret = -1;
+	while (lorawan_join(&join_cfg) < 0)
+	{
 		LOG_ERR("lorawan_join_network failed: %d, retrying..", ret);
+		// use another dev nonce
+		join_cfg.otaa.dev_nonce = sys_rand16_get();
 		k_sleep(K_MSEC(5000));
 	}
-	LOG_INF("Joining network over OTAA");
+	LOG_INF("Succesfully joined network over OTAA");
 }
 
-void send_data_packet(char *data) {
+void send_data_packet(char *data, uint8_t data_len)
+{
 	LOG_INF("Sending data...");
 	while (1)
 	{
-		int8_t ret = lorawan_send(LORAWAN_PORT, data, sizeof(data), LORAWAN_MSG_CONFIRMED);
+		int8_t ret = lorawan_send(LORAWAN_PORT, (uint8_t *)data, data_len, LORAWAN_MSG_UNCONFIRMED);
 
 		if (ret == -EAGAIN)
 		{
 			LOG_ERR("lorawan_send failed: %d. Continuing...", ret);
-			k_sleep(DELAY);
+			k_sleep(RETRY_DELAY);
 			continue;
 		}
-
-		if (ret < 0)
+		else if (ret < 0)
 		{
 			LOG_ERR("lorawan_send failed: %d", ret);
-			k_sleep(DELAY);
-			continue;
+			k_sleep(RETRY_DELAY);
+			break;
 		}
 		else
 		{
 			LOG_INF("Data sent!");
+			break;
 		}
 
-		k_sleep(DELAY);
+		k_sleep(RETRY_DELAY);
 	}
 }
 
-
-
-static void dl_callback(uint8_t port, uint8_t flags, int16_t rssi, int8_t snr, uint8_t len,
-						const uint8_t *hex_data)
+void create_data_package(char *buffer, float temp_room_mlx, float temp_floor, float humidity, uint8_t relais_state)
 {
-	LOG_INF("Port %d, Pending %d, RSSI %ddB, SNR %ddBm, Time %d", port,
-			flags & LORAWAN_DATA_PENDING, rssi, snr, !!(flags & LORAWAN_TIME_UPDATED));
-	if (hex_data)
-	{
-		LOG_HEXDUMP_INF(hex_data, len, "Payload: ");
-	}
-}
+	int16_t temp = (int16_t)(temp_room_mlx * 100);
+	int16_t floor_temp = (int16_t)(temp_floor * 100);
+	int16_t hum = (int16_t)(humidity * 100);
 
-static void lorwan_datarate_changed(enum lorawan_datarate dr)
-{
-	uint8_t unused, max_size;
-
-	lorawan_get_payload_sizes(&unused, &max_size);
-	LOG_INF("New Datarate: DR_%d, Max Payload %d", dr, max_size);
+	// Packen der Daten in das Byte-Array
+	buffer[0] = (temp >> 8) & 0xFF;
+	buffer[1] = temp & 0xFF;
+	buffer[2] = (floor_temp >> 8) & 0xFF;
+	buffer[3] = floor_temp & 0xFF;
+	buffer[4] = (hum >> 8) & 0xFF;
+	buffer[5] = hum & 0xFF;
+	buffer[6] = relais_state;
 }
\ No newline at end of file
diff --git a/src/lora/lorawan.h b/src/lora/lorawan.h
index d0ec396..57ead51 100644
--- a/src/lora/lorawan.h
+++ b/src/lora/lorawan.h
@@ -1,23 +1,20 @@
 #include <zephyr/kernel.h>
 #include <zephyr/lorawan/lorawan.h>
 
-
 #define LORAWAN_PORT 2
 
 /* Customize based on network configuration */
-#define LORAWAN_DEV_EUI			{ 0x2D, 0xBF, 0xF6, 0xC2, 0xA1, 0x20,\
-	0x01, 0x4A }
-#define LORAWAN_JOIN_EUI		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
-	0x00, 0x00 }
-/* #define LORAWAN_APP_KEY			{ 0x71, 0x5A, 0x39, 0xB2, 0x86, 0xC3,\
-	0x37, 0xA3, 0xC4, 0xF0, 0x78, 0xF9,\
-	0x0F, 0x33, 0x07, 0x7D } */
-#define LORAWAN_APP_KEY			{ 0x71, 0x5A, 0x39, 0xB2, 0x86, 0xC3,\
-	0x37, 0xA3, 0xC4, 0xF0, 0x78, 0xF9,\
-	0x0F, 0x33, 0x07, 0x7D }
+#define LORAWAN_APP_KEY {0x71, 0x5A, 0x39, 0xB2, 0x86, 0xC3, \
+						 0x37, 0xA3, 0xC4, 0xF0, 0x78, 0xF9, \
+						 0x0F, 0x33, 0x07, 0x7D}
 
-	
-static void dl_callback(uint8_t port, uint8_t flags, int16_t rssi, int8_t snr, uint8_t len,
-						const uint8_t *hex_data);
+#define RETRY_DELAY K_MSEC(1000)
+#define SEND_INTERVALL K_SECONDS(20)
 
-static void lorwan_datarate_changed(enum lorawan_datarate dr);
\ No newline at end of file
+void init_lorawan();
+
+void join_network_otaa();
+
+void send_data_packet(char *data, uint8_t data_len);
+
+void create_data_package(char *package, float temp_room_mlx, float temp_floor, float humidity, uint8_t relais_state);
\ No newline at end of file
diff --git a/src/main.c b/src/main.c
index 8679d24..d91ba06 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2,28 +2,54 @@
 #include <zephyr/logging/log.h>
 #include <zephyr/device.h>
 #include <zephyr/devicetree.h>
-#include <zephyr/lorawan/lorawan.h>
-#include <zephyr/drivers/i2c.h>
-#include <zephyr/drivers/sensor.h>
+#include <zephyr/sys/printk.h>
 #include <zephyr/drivers/sensor/sht4x.h>
+#include <zephyr/drivers/gpio.h>
 
 #include <lora/lorawan.h>
 #include <sensors/mlx90614.h>
 #include <sensors/sht4x.h>
+#include <gpio.h>
 
+LOG_MODULE_REGISTER(g2h_heat_main);
 
-
-#define DELAY K_MSEC(10000)
-#define LOG_LEVEL CONFIG_LOG_DEFAULT_LEVEL
-
-
-LOG_MODULE_REGISTER(lorawan_class_a);
-
-
+volatile bool relais_state = false;
 
 /* MAIN */
 int main(void)
 {
 
+	/* Initialization */
+	init_gpio();
+	init_mlx90614();
+	init_sht4x();
+	init_lorawan();
+	join_network_otaa();
 
+	float humidity, temp, floor_temp;
+
+	while (true)
+	{
+		/* Get values from SHT4X */
+		request_sensor_data_sht4x();
+		humidity = get_value_from_current_sample_sht4x(SENSOR_CHAN_HUMIDITY);
+		printk("hum: %.2f%%\n", humidity);
+
+		/* Get values from MLX90614 */
+		request_sensor_data_mlx90614(MLX90614_INTERNAL_TEMP_ADDR);
+		temp = get_temp_from_raw_data_mlx90614();
+		printk("temp: %.2f °C\n", temp);
+		request_sensor_data_mlx90614(MLX90614_IR_TEMP_ADDR);
+		floor_temp = get_temp_from_raw_data_mlx90614();
+		printk("floor_temp: %.2f °C\n", floor_temp);
+
+		/* Pack and send values */
+		char data[7];
+		create_data_package(data, temp, floor_temp, humidity, relais_state);
+		LOG_HEXDUMP_DBG(data, 7, "data");
+		send_data_packet(data, 7);
+
+		/* Delay until next cycle */
+		k_sleep(SEND_INTERVALL);
+	}
 }
\ No newline at end of file
diff --git a/src/sensors/mlx90614.c b/src/sensors/mlx90614.c
index c8810aa..43aeaed 100644
--- a/src/sensors/mlx90614.c
+++ b/src/sensors/mlx90614.c
@@ -3,13 +3,16 @@
 #include <zephyr/kernel.h>
 #include <zephyr/drivers/i2c.h>
 #include <zephyr/devicetree.h>
+#include <zephyr/logging/log.h>
 
-static struct device *i2c_dev;
-static uint16_t i2c_addr = 0x00;
+LOG_MODULE_REGISTER(mlx90614);
 
-void init_mlx90614() {
+static const struct device *i2c_dev;
+static const uint16_t i2c_addr = 0x5A;
+static uint8_t read_data_buffer[3];
+
+int init_mlx90614() {
 	i2c_dev = DEVICE_DT_GET(DT_NODELABEL(i2c1));
-	i2c_addr = DT_PROP(DT_NODELABEL(mlx90614), reg);
 
 	if (!i2c_dev) {
 		LOG_ERR("I2C device not found!");
@@ -17,27 +20,27 @@ void init_mlx90614() {
 	} else {
 		LOG_INF("I2C device initialized.");
 	}
-	
-	if (i2c_addr == 0x00) {
-		LOG_ERR("MLX90614 I2C address fetch from device tree failed!");
-	} else {
-		LOG_INF("MLX90614 I2C address found.");
-	}
 }
 
-void request_sensor_data_mlx90614(uint16_t target_addr, const uint8_t *read_data) {
-	for (int i = 0; i < MLX90614_RETRY_COUNT; i++) {
-		if (i2c_write_read(i2c_dev, i2c_addr, &target_addr, sizeof(target_addr), &read_data, sizeof(read_data) == 0)) {
+void request_sensor_data_mlx90614(uint8_t target_addr) {
+	uint8_t err;
+	for (int i = 0; i < MLX90614_RETRY_COUNT; i++)
+	{
+		err = i2c_write_read(i2c_dev, 0x5A, &target_addr, sizeof(target_addr), &read_data_buffer, sizeof(read_data_buffer));
+		if (err == 0)
+		{
 			LOG_INF("MLX90614 sensor values successfully read after %d tries", i+1);
 			return;
-		} else {
+		}
+		else
+		{
 			k_sleep(K_MSEC(100));
 		}
 	}
-	LOG_ERR("MLX90614 reading sensor values failed %d times!", MLX90614_RETRY_COUNT);
+	LOG_ERR("MLX90614 reading sensor values failed %d times with error %d!", MLX90614_RETRY_COUNT, err);
 }
 
-float get_temp_from_raw_data_mlx90614(const uint8_t *read_data) {
-	int16_t temperature = (read_data[1] << 8) | read_data[0]; // Temperaturwert aus den empfangenen Daten
-	return temperature * 0.02 - 273.15;		  // Umrechnung in Celsius
+float get_temp_from_raw_data_mlx90614() {
+	int16_t temperature = (read_data_buffer[1] << 8) | read_data_buffer[0]; // Temperaturwert aus den empfangenen Daten
+	return temperature * 0.02 - 273.15; // Umrechnung in Celsius
 }
\ No newline at end of file
diff --git a/src/sensors/mlx90614.h b/src/sensors/mlx90614.h
index 83ff841..1793f49 100644
--- a/src/sensors/mlx90614.h
+++ b/src/sensors/mlx90614.h
@@ -6,6 +6,6 @@
 
 int init_mlx90614();
 
-int request_sensor_data_mlx90614(uint16_t target_addr, const uint8_t *read_data);
+void request_sensor_data_mlx90614(uint8_t target_addr);
 
-float get_temp_from_raw_data_mlx90614(const uint8_t *read_data);
\ No newline at end of file
+float get_temp_from_raw_data_mlx90614();
\ No newline at end of file
diff --git a/src/sensors/sht4x.c b/src/sensors/sht4x.c
index f76e173..6556eac 100644
--- a/src/sensors/sht4x.c
+++ b/src/sensors/sht4x.c
@@ -5,7 +5,9 @@
 #include <zephyr/drivers/sensor.h>
 #include <zephyr/drivers/sensor/sht4x.h>
 
-static struct device *sht;
+LOG_MODULE_REGISTER(sht4x);
+
+static const struct device *sht;
 
 void init_sht4x()
 {
@@ -46,10 +48,10 @@ float get_value_from_current_sample_sht4x(enum sensor_channel sensor)
 	float result;
 	if (sensor_channel_get(sht, sensor, &value) == 0) {
 		result = sensor_value_to_double(&value);
-		LOG_INF("Value '%s' successfully read [%f]", sensor, result);
+		printf("Value '%s' successfully read [%f]", sensor, result);
 	} else {
 		LOG_ERR("Can't read sensor value '%s' from sample!", sensor);
 		return 0.0;
 	}
-	return value;
+	return result;
 }
\ No newline at end of file
diff --git a/src/sensors/sht4x.h b/src/sensors/sht4x.h
index 27455e5..e701722 100644
--- a/src/sensors/sht4x.h
+++ b/src/sensors/sht4x.h
@@ -6,4 +6,4 @@ void init_sht4x();
 
 void request_sensor_data_sht4x();
 
-float get_value_from_raw_data_sht4x(enum sensor_channel sensor);
\ No newline at end of file
+float get_value_from_current_sample_sht4x(enum sensor_channel sensor);
\ No newline at end of file
diff --git a/zephyr/boards/st/g2h_lorawan_heat_control/g2h_lorawan_heat_control.dts b/zephyr/boards/st/g2h_lorawan_heat_control/g2h_lorawan_heat_control.dts
index ae3d54e..2b6204b 100644
--- a/zephyr/boards/st/g2h_lorawan_heat_control/g2h_lorawan_heat_control.dts
+++ b/zephyr/boards/st/g2h_lorawan_heat_control/g2h_lorawan_heat_control.dts
@@ -10,6 +10,7 @@
 #include "arduino_r3_connector.dtsi"
 #include "st_morpho_connector.dtsi"
 #include <zephyr/dt-bindings/input/input-event-codes.h>
+//#include "g2h_lorawan_heat_control.dtsi"
 
 / {
 	model = "G2H LoraWAN Heat control based on STM32WL55JC-NUCLEO";
@@ -208,4 +209,4 @@ stm32_lp_tick_source: &lptim1 {
 
 &vbat {
 	status = "okay";
-};
+};
\ No newline at end of file
diff --git a/zephyr/boards/st/g2h_lorawan_heat_control/g2h_lorawan_heat_control.dtsi b/zephyr/boards/st/g2h_lorawan_heat_control/g2h_lorawan_heat_control.dtsi
new file mode 100644
index 0000000..db32aa2
--- /dev/null
+++ b/zephyr/boards/st/g2h_lorawan_heat_control/g2h_lorawan_heat_control.dtsi
@@ -0,0 +1,8 @@
+#include <zephyr/dt-bindings/pinctrl/stm32-pinctrl.h>
+#include <st/wl/stm32wl55jcix-pinctrl.dtsi>
+
+&pinctrl {
+    gpio_pc0: gpio_pc0 {
+        pinmux = <STM32_PINMUX(STM32_PORTC, 0, STM32_GPIO)>;
+    };
+};
diff --git a/zephyr/dts/bindings/power-switch.yaml b/zephyr/dts/bindings/power-switch.yaml
new file mode 100644
index 0000000..438faf1
--- /dev/null
+++ b/zephyr/dts/bindings/power-switch.yaml
@@ -0,0 +1,10 @@
+description: GPIO pin to switch a power output on or off
+
+compatible: "power-switch"
+
+properties:
+  gpios:
+    type: phandle-array
+    required: true
+    description: |
+      The GPIO connected to the gate driver for the MOSFET.
\ No newline at end of file
diff --git a/zephyr/g2h_lorawan_heat_control.overlay b/zephyr/g2h_lorawan_heat_control.overlay
new file mode 100644
index 0000000..08e6e90
--- /dev/null
+++ b/zephyr/g2h_lorawan_heat_control.overlay
@@ -0,0 +1,6 @@
+/ {
+	load_switch: load_switch {
+		compatible = "power-switch";
+		gpios = <&gpioc 0 GPIO_ACTIVE_HIGH>;
+	};
+};
\ No newline at end of file
diff --git a/zephyr/prj.conf b/zephyr/prj.conf
index 77c880e..3f075cf 100644
--- a/zephyr/prj.conf
+++ b/zephyr/prj.conf
@@ -1,12 +1,18 @@
 CONFIG_LOG=y
 CONFIG_SENSOR=y
+CONFIG_GPIO=y
+CONFIG_SETTINGS=y
+CONFIG_FLASH=y
+CONFIG_FLASH_MAP=y
+CONFIG_ZMS=y
 CONFIG_I2C=y
 CONFIG_SHT4X=y
 CONFIG_LORA=y
 CONFIG_LORAWAN=y
 CONFIG_LORAMAC_REGION_EU868=y
-CONFIG_MAIN_STACK_SIZE=2048
-CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048
+CONFIG_MAIN_STACK_SIZE=4096
+CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=4096
 CONFIG_LOG_DEFAULT_LEVEL=3
 CONFIG_NEWLIB_LIBC=y
-CONFIG_NEWLIB_LIBC_FLOAT_PRINTF=y
\ No newline at end of file
+CONFIG_NEWLIB_LIBC_FLOAT_PRINTF=y
+CONFIG_ENTROPY_GENERATOR=y
\ No newline at end of file