Implement optional iPol field for tx.

Author: brocaar

docs/changelog.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## 2.1.2
+
+* Add optional `iPol` field to `txInfo` struct in JSON to override the default
+  behaviour (which is `iPol=true` when using LoRa modulation)
+
 ## 2.1.1
 
 * Do not unmarshal and marshal PHYPayload on receiving / sending

docs/topics.md

@@ -79,3 +79,7 @@ Example payload:
     }
 }
 ```
+
+Optionally, the field `iPol` (type `bool`) can be used to control the
+LoRa modulation polarization inversion. When left blank (`null`), the default
+will be used (which is `true` for downlink LoRa modulation.

gateway/backend.go

@@ -447,8 +447,11 @@ func newTXPKFromTXPacket(txPacket gw.TXPacketBytes) (TXPK, error) {
 		txpk.FDev = uint16(txPacket.TXInfo.DataRate.BitRate / 2)
 	}
 
-	// TODO: do testing with FSK modulation
-	if txPacket.TXInfo.DataRate.Modulation == band.LoRaModulation {
+	// by default IPol=true is used for downlink LoRa modulation, however in
+	// some cases one might want to override this.
+	if txPacket.TXInfo.IPol != nil {
+		txpk.IPol = *txPacket.TXInfo.IPol
+	} else if txPacket.TXInfo.DataRate.Modulation == band.LoRaModulation {
 		txpk.IPol = true
 	}
 

gateway/backend_test.go

@@ -256,6 +256,55 @@ func TestNewGatewayStatPacket(t *testing.T) {
 	})
 }
 
+func TestNewTXPKFromTXPacket(t *testing.T) {
+	Convey("Given a TXPacket", t, func() {
+		txPacket := gw.TXPacketBytes{
+			TXInfo: gw.TXInfo{
+				Timestamp: 12345,
+				Frequency: 868100000,
+				Power:     14,
+				CodeRate:  "4/5",
+				DataRate: band.DataRate{
+					Modulation:   band.LoRaModulation,
+					SpreadFactor: 9,
+					Bandwidth:    250,
+				},
+			},
+			PHYPayload: []byte{1, 2, 3, 4},
+		}
+
+		Convey("Then te expected TXPK is returned (with default IPol", func() {
+			txpk, err := newTXPKFromTXPacket(txPacket)
+			So(err, ShouldBeNil)
+			So(txpk, ShouldResemble, TXPK{
+				Imme: false,
+				Tmst: 12345,
+				Freq: 868.1,
+				Powe: 14,
+				Modu: "LORA",
+				DatR: DatR{
+					LoRa: "SF9BW250",
+				},
+				CodR: "4/5",
+				Size: 4,
+				Data: "AQIDBA==",
+				IPol: true,
+			})
+		})
+
+		Convey("Given IPol is requested to false", func() {
+			f := false
+			txPacket.TXInfo.IPol = &f
+
+			Convey("Then the TXPK IPol is set to false", func() {
+				txpk, err := newTXPKFromTXPacket(txPacket)
+				So(err, ShouldBeNil)
+				So(txpk.IPol, ShouldBeFalse)
+			})
+		})
+	})
+}
+
 func TestNewRXPacketFromRXPK(t *testing.T) {
 	Convey("Given a (Semtech) RXPK and gateway MAC", t, func() {
 		now := time.Now().UTC()

mkdocs.yml

@@ -16,7 +16,7 @@ pages:
     - Kerlink IoT Station: gateways/kerlink-iot-station.md
 
 extra:
-  version: '2.1.1'
+  version: '2.1.2'
   github:
     download_release: true
 

vendor/github.com/brocaar/loraserver/api/gw/gw.go

@@ -9,10 +9,10 @@
 			"revisionTime": "2016-06-01T11:32:10Z"
 		},
 		{
-			"checksumSHA1": "aFJowcDa1NphX/ZeDpjuTdd6Ek0=",
+			"checksumSHA1": "rHBPrqOaYAGyF0JupgYmj4643+k=",
 			"path": "github.com/brocaar/loraserver/api/gw",
-			"revision": "223fc82d79ba63547cd1249379a2b1dce69a3555",
-			"revisionTime": "2016-09-25T18:21:44Z"
+			"revision": "b7ac42216a89370da930250f3cce4221937fae61",
+			"revisionTime": "2016-09-27T17:54:38Z"
 		},
 		{
 			"checksumSHA1": "ya7tMk+wexXh1cmbdp0Sw0lbM1k=",