Added APRS equations packet support

TelemetryEquationsReport will generate a string of equation parameters to
scale telemetry data to.

aprslib/packets/__init__.py

@@ -1,4 +1,5 @@
 from aprslib.packets.position import PositionReport
 from aprslib.packets.telemetry import TelemetryReport
 from aprslib.packets.telemetryunitlabels import TelemetryUnitLabelsReport
-from aprslib.packets.telemetryparameters import TelemetryParametersReport
+from aprslib.packets.telemetryparameters import TelemetryParametersReport
+from aprslib.packets.telemetryequations import TelemetryEquationsReport

aprslib/packets/telemetryequations.py

@@ -0,0 +1,47 @@
+from aprslib.packets.base import APRSPacket
+
+class TelemetryEquationsReport(APRSPacket):
+    format = 'raw'
+    telemetrystation = "N0CALL"
+    a1a = "0.0"
+    a1b = "9999.0"
+    a1c = "0.0"
+    a2a = "0.0"
+    a2b = "1.0"
+    a2c = "0.0"
+    a3a = "0.0"
+    a3b = "1.0"
+    a3c = "0.0"
+    a4a = "0.0"
+    a4b = "1.0"
+    a4c = "0.0"
+    a5a = "0.0"
+    a5b = "1.0"
+    a5c = "0.0"
+
+    def _serialize_body(self):
+
+        body = [
+            ':{0} :EQNS.'.format(self.telemetrystation),  # packet type
+            self.a1a,
+            self.a1b,
+            self.a1c,
+            self.a2a,
+            self.a2b,
+            self.a2c,
+            self.a3a,
+            self.a3b,
+            self.a3c,
+            self.a4a,
+            self.a4b,
+            self.a4c,
+            self.a5a,
+            self.a5b,
+            self.a5c,
+        ]
+        tmpbody = ",".join(body)
+        badcomma = tmpbody.index(",")
+
+        # remove static but erroneous comma between EQNS. and a1 value
+        # Position can vary due to callsign
+        return tmpbody[:badcomma] + tmpbody[badcomma+1:]