diff --git a/software/lib/MQ135.py b/software/lib/MQ135.py
index bb3f976..dfa35e5 100644
--- a/software/lib/MQ135.py
+++ b/software/lib/MQ135.py
@@ -57,7 +57,11 @@ def get_corrected_ppm(self, temperature, humidity):
         """Returns the ppm of CO2 sensed (assuming only CO2 in the air)
         corrected for temperature/humidity"""
         g_cr = self.get_corrected_resistance(temperature, humidity)
-        return self.PARA * math.pow((g_cr / self.RZERO), -self.PARB)
+        try:
+            val = self.PARA * math.pow((g_cr / self.RZERO), -self.PARB)
+        except:
+            val = 0
+        return val
 
     def get_rzero(self):
         """Returns the resistance RZero of the sensor (in kOhms) for calibration purposes"""
diff --git a/software/lib/SDS011.py b/software/lib/SDS011.py
index 4e76d0a..7810fbf 100644
--- a/software/lib/SDS011.py
+++ b/software/lib/SDS011.py
@@ -50,8 +50,8 @@ def make_command(self, cmd, mode, param):
         return header + cmd + mode + param + padding + checksum + tail
 
     def get_response(self, command_ID):
-        # try for 120 bytes (0.1) second to get a response from sensor (typical response time 12~33 bytes)
-        for _ in range(120):
+        # try for 120 bytes (0.2) second to get a response from sensor (typical response time 12~33 bytes)
+        for _ in range(240):
             try:
                 header = self._uart.read(1)
                 if header == b'\xaa':
diff --git a/software/main.py b/software/main.py
index 85ae3d6..b6fbe0d 100644
--- a/software/main.py
+++ b/software/main.py
@@ -25,6 +25,7 @@
     display.text("GPS gestart!", 1, 1)
     display.show()
     
+    t1 = time.time()
     while True:
         while com2.any():                                       # wait for incoming communication
             print('.', end = '')
@@ -32,7 +33,7 @@
             for x in my_sentence:
                 gps.update(chr(x))                              # decode it through micropyGPS
 
-        if gps.latitude > 0 and gps.longitude > 0:              # once we found valid data, power off GPS module and show data on display
+        if (gps.latitude > 0 and gps.longitude > 0) or time.time() - t1 > 60:   # once we found valid data, power off GPS module and show data on display
             gps_en.value(1)                                     # disable GPS power
 
             print("GPS: NB %f, OL %f, H %f" % (gps.latitude, gps.longitude, gps.altitude))
@@ -82,9 +83,15 @@
     lora = network.LoRa(mode = network.LoRa.LORAWAN, region = network.LoRa.EU868, sf = settings.LORA_SF)            # create LoRa object
     
     if wake_reason != machine.RTC_WAKE and wake_reason != machine.PIN_WAKE:
-        app_eui = ubinascii.unhexlify(settings.APP_EUI)
-        app_key = ubinascii.unhexlify(settings.APP_KEY)
-        lora.join(activation = network.LoRa.OTAA, auth = (app_eui, app_key), timeout = 0, dr = settings.LORA_DR)    # join with SF9
+        #app_eui = ubinascii.unhexlify(settings.APP_EUI)
+        #app_key = ubinascii.unhexlify(settings.APP_KEY)
+        #lora.join(activation = network.LoRa.OTAA, auth = (app_eui, app_key), timeout = 0, dr = settings.LORA_DR)    # join with SF9
+        
+        dev_addr = struct.unpack(">l", ubinascii.unhexlify('260BD834'))[0]
+        nwk_swkey = ubinascii.unhexlify('ABA8C83456AA7F0537BD1998017F77F0')
+        app_swkey = ubinascii.unhexlify('0C4A1DD8684BFC394705D06963E1E690')
+        lora.join(activation = network.LoRa.ABP, auth = (dev_addr, nwk_swkey, app_swkey), dr = settings.LORA_DR)
+        
         display.poweron()
         display.text("Verbinden...", 1, 1)
         display.show()
@@ -93,7 +100,7 @@
         while not lora.has_joined():
             print('.', end = '')
             time.sleep(0.5)
-
+            
         display.text("Verbonden!", 1, 11)
         display.show()
 
@@ -134,7 +141,7 @@
 mq135_en = machine.Pin('P8', mode=machine.Pin.OUT)          # MQ135 VIN pin
 mq135_en.hold(False)                                        # disable hold from deepsleep
 mq135_en.value(1)                                           # preheat
-mq135 = MQ135('P17')                                        # CO2 sensor
+mq135 = MQ135('P16')                                        # CO2 sensor
                                                             # active: 40 mA, sleep: 0.0 mA
 
 sds011_en = machine.Pin('P21', mode=machine.Pin.OUT)        # voltage regulator SHDN pin
@@ -183,7 +190,8 @@
 else:
     machine.sleep((settings.WAKE_TIME - settings.PEAK_TIME) * 1000)
 
-while not sds011.read():    # make sure we get response from SDS011
+t1 = time.time()
+while (not sds011.read()) and (time.time() - t1 < 5):    # try to get a response from SDS011 within 5 seconds
     pass
 
 pm_25 = sds011.pm25
diff --git a/software/settings.py b/software/settings.py
index 87e194b..90d377b 100644
--- a/software/settings.py
+++ b/software/settings.py
@@ -1,16 +1,16 @@
 ## Here we store settings, credentials and constants.
 
 # LoRa config info
-APP_EUI = '30AEA459134C0000'
-APP_KEY = '38C9AD4E8B69241FE50AB179932CAE1F'
-LORA_SF = 9             # LoRa Spreading Factor (7 to 12)
+APP_EUI = '30AEA47870B40000'
+APP_KEY = '93F032DE681792632F0B928B555DAAB8'
+LORA_SF = 12             # LoRa Spreading Factor (7 to 12)
 LORA_DR = 12 - LORA_SF  # Data Rate complement of Spreading Factor (counted inversely from 0 to 5)
 
 MEASURE_INTERVAL = 60  # measure every ... seconds
 BOOT_TIME = 3           # time in seconds (approx) it takes to start SDS011 from poweron
-WAKE_TIME = 30          # time in seconds that the SDS011 and MQ135 need to stabilize
+WAKE_TIME = 32          # time in seconds that the SDS011 and MQ135 need to stabilize
 PEAK_TIME = 6           # time in seconds to wait after starting voltage regulator
 DISPLAY_TIME = 6        # time in seconds to display values on the internal display
 SLEEP_TIME = MEASURE_INTERVAL - BOOT_TIME - WAKE_TIME
 
-DEBUG_MODE = True
\ No newline at end of file
+DEBUG_MODE = False
\ No newline at end of file