allow setting APN (#79)

Hologram/Network/Modem/BG96.py

@@ -176,7 +176,7 @@ def set_network_registration_status(self):
     def _set_up_pdp_context(self):
         if self._is_pdp_context_active(): return True
         self.logger.info('Setting up PDP context')
-        self.set('+QICSGP', '1,1,\"hologram\",\"\",\"\",1')
+        self.set('+QICSGP', f'1,1,\"{self._apn}\",\"\",\"\",1')
         ok, _ = self.set('+QIACT', '1', timeout=30)
         if ok != ModemResult.OK:
             self.logger.error('PDP Context setup failed')

Hologram/Network/Modem/Modem.py

@@ -74,6 +74,7 @@ def __init__(self, device_name=None, baud_rate='9600',
         self.result = ModemResult.OK
         self.debug_out = ''
         self.in_ext = False
+        self._apn = 'hologram'
 
         self._initialize_device_name(device_name)
 
@@ -711,7 +712,7 @@ def _is_pdp_context_active(self):
     def _set_up_pdp_context(self):
         if self._is_pdp_context_active(): return True
         self.logger.info('Setting up PDP context')
-        self.set('+UPSD', '0,1,\"hologram\"')
+        self.set('+UPSD', f'0,1,\"{self._apn}\"')
         self.set('+UPSD', '0,7,\"0.0.0.0\"')
         ok, _ = self.set('+UPSDA', '0,3', timeout=30)
         if ok != ModemResult.OK:
@@ -913,11 +914,19 @@ def remoteIPAddress(self):
         else:
             return None
 
-
     @property
     def version(self):
         raise NotImplementedError('This modem does not support this property')
 
     @property
     def imei(self):
         return self._basic_command('+GSN')
+
+    @property
+    def apn(self):
+        return self._apn
+
+    @apn.setter
+    def apn(self, apn):
+        self._apn = apn
+        return self.set('+CGDCONT', f'1,"IP","{self._apn}"')