diff --git a/main.py b/main.py
index 6cf6dc9..f7c1d9a 100644
--- a/main.py
+++ b/main.py
@@ -40,45 +40,48 @@ def relay_controller(pin: int, state: str):
         error_print("Unknown state ("+state+") for relay channel "+str(pin))
 
 #ultrasonic
-def get_water_level():
-    GPIO.setmode(GPIO.BCM)
-    GPIO.setwarnings(False)
-    GPIO_TRIGGER = 24
-    GPIO_ECHO = 25
-    GPIO.setup(GPIO_TRIGGER, GPIO.OUT)
-    GPIO.setup(GPIO_ECHO, GPIO.IN)
-    GPIO.output(GPIO_TRIGGER, True)
-    time.sleep(0.00001)
-    GPIO.output(GPIO_TRIGGER, False)
- 
-    startTime = time.time()
-    StopTime = time.time()
- 
-    while GPIO.input(GPIO_ECHO) == 0:
+try:
+    def get_water_level():
+        GPIO.setmode(GPIO.BCM)
+        GPIO.setwarnings(False)
+        GPIO_TRIGGER = 24
+        GPIO_ECHO = 25
+        GPIO.setup(GPIO_TRIGGER, GPIO.OUT)
+        GPIO.setup(GPIO_ECHO, GPIO.IN)
+        GPIO.output(GPIO_TRIGGER, True)
+        time.sleep(0.00001)
+        GPIO.output(GPIO_TRIGGER, False)
+    
         startTime = time.time()
-    while GPIO.input(GPIO_ECHO) == 1:
         StopTime = time.time()
- 
-    TimeElapsed = StopTime - startTime
-    distance = (TimeElapsed * 34300) / 2
-    rounded_distance = int(distance)
-    return str(rounded_distance)
+    
+        while GPIO.input(GPIO_ECHO) == 0:
+            startTime = time.time()
+        while GPIO.input(GPIO_ECHO) == 1:
+            StopTime = time.time()
+    
+        TimeElapsed = StopTime - startTime
+        distance = (TimeElapsed * 34300) / 2
+        rounded_distance = int(distance)
+        return str(rounded_distance)
 
-debug_print("Added water level detector")
+    print(get_water_level())
+    debug_print("Added water level detector")
+except:
+    print("Adding water level sensor fail.")
 
 #temperature
-def get_temperature():
-    i2c = busio.I2C(board.SCL, board.SDA)
-    bmp280 = adafruit_bmp280.Adafruit_BMP280_I2C(i2c, address=0x76)
-    rounded_temp = int(bmp280.temperature)
-    return str(rounded_temp)
+try:
+    def get_temperature():
+        i2c = busio.I2C(board.SCL, board.SDA)
+        bmp280 = adafruit_bmp280.Adafruit_BMP280_I2C(i2c, address=0x76)
+        rounded_temp = int(bmp280.temperature)
+        return str(rounded_temp)
 
-debug_print("Added temperature sensor")
-
-print(get_water_level())
-debug_print("got water level")
-print(get_temperature())
-debug_print("got temperature")
+    debug_print("Added temperature sensor")
+    print(get_temperature())
+except:
+    print("Adding temperature sensor faild.")
 
 def mqtt_on_connect(client, userdata, flags, rc):
     client.subscribe("strawberry-pi-greenhouse/relay/channel/1")