add radar support

docs/decoding.txt

@@ -1,3 +1,5 @@
+Ultraschall - LDDS75
+
 http://wiki.dragino.com/xwiki/bin/view/Main/User%20Manual%20for%20LoRaWAN%20End%20Nodes/LDDS75%20-%20LoRaWAN%20Distance%20Detection%20Sensor%20User%20Manual/
 
 
@@ -22,3 +24,32 @@ status = struct.unpack('?', frame[7:8])[0]
 print(f"{battery=}, {distance=}, {status=}")
 
 payload = 'DRgAAAAAAAE='
+
+
+
+
+Radar - LMDS200
+
+http://wiki.dragino.com/xwiki/bin/view/Main/User%20Manual%20for%20LoRaWAN%20End%20Nodes/LMDS200%20-%20LoRaWAN%20Microwave%20Radar%20Distance%20%20Sensor%20User%20Manual/
+
+
+Value, Size (bytes), FPORT = 2
+Battery (mV), 2
+Distance 1 (cm), 2
+Distance 2 (cm), 2
+Status, 1
+
+
+import base64
+import struct
+
+payload = 'DN4AqQD8AA=='
+frame = base64.b64decode(payload)
+
+battery = struct.unpack('>H', frame[0:2])[0]
+distance1 = struct.unpack('>H', frame[2:4])[0]
+distance2 = struct.unpack('>H', frame[4:6])[0]
+
+print(f"{battery=}, {distance1=}, {distance2=}")
+
+

src/preprocess.py

@@ -19,6 +19,8 @@ class SensorTypeNotFoundException (Exception):
     def __init__(self, sensorType):
         self.sensorType = sensorType
 
+class JustIgnoreMessage (Exception): pass
+
 class DbOp(object):
     def __init__(self, config):
         self.conn = None
@@ -95,6 +97,7 @@ def mqttOnMessageCallback(client, userdata, message):
         application = dbh.getApplication(device_id)
 
         frame = base64.b64decode(parse_payload['uplink_message']['frm_payload'])
+        f_port = parse_payload['uplink_message']['f_port']
         measurement = {}
         
         match application['sensor_type']:
@@ -117,11 +120,35 @@ def mqttOnMessageCallback(client, userdata, message):
                     'status': statusText,
                     'battery': battery / 1000
                 }
+            case 'LMDS200':
+                if f_port != 2:
+                    raise JustIgnore()
+                battery = struct.unpack('>H', frame[0:2])[0]
+                distance1 = struct.unpack('>H', frame[2:4])[0]
+                distance2 = struct.unpack('>H', frame[4:6])[0]
+                status = struct.unpack('?', frame[7:8])[0]
+                logger.debug(f"{frame=}, {battery=}, {distance1=}, {distance2=}")
+
+                statusText = 'Ok'
+                if distance1 == 1:
+                    statusText = 'No sensor'
+                elif distance1 == 2:
+                    statusText = 'Out of range'
+
+                measurement = {
+                    'application_name': application['label'],
+                    'raw_level': distance1,
+                    'level': application['ground_level'] - distance1,
+                    'status': statusText,
+                    'battery': battery / 1000
+                }
             case _:
                 raise SensorTypeNotFoundException(application['sensor_type'])
 
         logger.debug(f"{measurement=}")
         dbh.storeMeasurement(measurement)
+    except JustIgnore:
+        pass
     except SensorTypeNotFoundException as e:
         logger.error(f"application has unknown sensor type {e.sensorType}")
     except ApplicationNotFoundException as e: