diff --git a/config.py b/config.py
index 774d099..ebd9ec1 100644
--- a/config.py
+++ b/config.py
@@ -13,4 +13,4 @@ PAYLOAD_TOPIC = b'IoT/rpipwThermometer/0/Payload'
 STARTUP_TOPIC = b'IoT/rpipwThermometer/0/Startup'
 
 MAX_CONNECT_RETRY_CNT = 25
-MAIN_PERIOD_MS = 60000
\ No newline at end of file
+MAIN_PERIOD_S = 60
\ No newline at end of file
diff --git a/main.py b/main.py
index 27856e0..1961d0d 100644
--- a/main.py
+++ b/main.py
@@ -1,38 +1,30 @@
-# main.py -- put your code here!
-
-from umqttsimple import MQTTClient, MQTTException
+import machine
+from umqttsimple import MQTTClient
 import time
 import ubinascii
-from machine import WDT
+# from machine import WDT
 import network
 import os
 import config
 
-last_message = 0
-message_interval = 5
-counter = 0
-ringFlag = False
-wdt = None
-wdtCnt = 0
-client = None
-wlan = None
 
 
-def init():
-    global wdt
-    wdt = WDT(timeout=8000)
-    wdt.feed()
-    print("Watchdog enabled")
+print("Hello")
+resetCause = machine.reset_cause()
 
-    global wlan
+# wdt = WDT(timeout=8000)
+# wdt.feed()
+# print("Watchdog enabled")
+
+try:
     wlan = network.WLAN(network.STA_IF)
     wlan.active(True)
     wlan.connect(config.SSID, config.WPA_KEY)
 
     connectCnt = 0
-    while (not wlan.isconnected() or connectCnt > config.MAX_CONNECT_RETRY_CNT):
+    while (not wlan.isconnected() or (connectCnt > config.MAX_CONNECT_RETRY_CNT)):
         print("Not yet connected")
-        wdt.feed()
+        # wdt.feed()
         connectCnt += 1
         time.sleep(1)
 
@@ -40,64 +32,42 @@ def init():
         print("Failed to connect to wlan, restarting")
         machine.reset()
 
-    print(f"Connected to WLAN: {machine.reset_cause()} {connectCnt} {wlan.ifconfig()}")
+    print(f"Connected to WLAN: {resetCause} {connectCnt} {wlan.ifconfig()}")
+    # wdt.feed()
 
-    global client
-    clientId = ubinascii.hexlify(bytearray(os.urandom(16))).decode()
+    clientId = f"rpipwtherm-{ubinascii.hexlify(machine.unique_id())}"
     client = MQTTClient(clientId, config.MQTT_SERVER, keepalive=60, 
         ssl=True, user=config.MQTT_LOGIN, password=config.MQTT_PASSWORD)
-    client.set_callback(mqtt_callback)
     client.connect()
     print(f"Connected to MQTT broker {config.MQTT_SERVER} ")
-    client.subscribe(config.WATCHDOG_TOPIC)
-    print(f"Subscribed to {config.WATCHDOG_TOPIC}")
+    # wdt.feed()
+
     client.publish(config.STARTUP_TOPIC, f"Hello, rpipw thermometer is alive now at {wlan.ifconfig()}")
+except Exception as e:
+    print(f"Some error when starting: {e.__class__.__name__}, {e}")
+    time.sleep(15)
+    machine.reset()
 
 
-def mqtt_callback(topic, msg):
-    global wdt, wdtCnt
-    # print(f"Received: {topic}: {msg}")
-    if topic == config.WATCHDOG_TOPIC:
-        wdtCnt += 1
-        # print(f"feed watchdog {wdtCnt}")
-        wdt.feed()
-
-def main():
-    global client
-    print("Hello")
-    time.sleep(1)
-
-    try:
-        init()
-    except Exception as e:
-        print(f"Some error when starting: {e.__class__.__name__}, {e}")
-        time.sleep(15)
-        machine.reset()
-
-    last_time_mqtt_loop = time.ticks_ms()
-    last_time_1_second = time.ticks_ms()
-    last_time_main_period = time.ticks_ms()
-    payload_cnt = 0
-    while True:
-        current_time = time.ticks_ms()
-
-        if (time.ticks_diff(current_time, last_time_mqtt_loop) > 250):
-            last_time_mqtt_loop = current_time
-            client.ping()
-            client.wait_msg()
-
-        if (time.ticks_diff(current_time, last_time_1_second) > 1000):
-            last_time_1_second = current_time
-            client.publish(config.HEARTBEAT_TOPIC, f"still alive {current_time}")
-
-        if (time.ticks_diff(current_time, last_time_main_period) > config.MAIN_PERIOD_MS):
-            last_time_main_period = current_time
-            client.publish(config.PAYLOAD_TOPIC, f"measurement {payload_cnt}")
-            payload_cnt += 1
-            print("Payload sent")
-
+try:
+    client.publish(config.PAYLOAD_TOPIC, f"measurement")
+    print("Payload sent")
+    # wdt.feed()
 
     client.disconnect()
-    
-if __name__ == "__main__":
-    main()
\ No newline at end of file
+    print("Disconnected from broker")
+    time.sleep(1)
+    wlan.disconnect()
+    wlan.active(False)
+    print("Disconnected from network")
+except Exception as e:
+    print(f"Error in main loop: {e.__class__.__name__}, {e}")
+finally:
+    print("Waiting ...")
+    # wdt.feed()
+
+    time.sleep(config.MAIN_PERIOD_S)
+    print("Restarting")
+    time.sleep(1)
+    machine.reset()
+