Merge pull request #42 from bemasher/SCM+

Add SCM+ parser.

flags.go

@@ -38,7 +38,7 @@ var logFile *os.File
 var sampleFilename = flag.String("samplefile", os.DevNull, "raw signal dump file")
 var sampleFile *os.File
 
-var msgType = flag.String("msgtype", "scm", "message type to receive: scm, idm or r900")
+var msgType = flag.String("msgtype", "scm", "message type to receive: scm, idm, r900 or scm+")
 
 var symbolLength = flag.Int("symbollength", 72, "symbol length in samples")
 

recv.go

@@ -32,6 +32,7 @@ import (
 	"github.com/bemasher/rtlamr/parse"
 	"github.com/bemasher/rtlamr/r900"
 	"github.com/bemasher/rtlamr/scm"
+	"github.com/bemasher/rtlamr/scmplus"
 	"github.com/bemasher/rtltcp"
 )
 
@@ -51,6 +52,8 @@ func (rcvr *Receiver) NewReceiver() {
 		rcvr.p = idm.NewParser(*symbolLength, *decimation)
 	case "r900":
 		rcvr.p = r900.NewParser(*symbolLength, *decimation)
+	case "scm+":
+		rcvr.p = scmplus.NewParser(*symbolLength, *decimation)
 	default:
 		log.Fatalf("Invalid message type: %q\n", *msgType)
 	}

scmplus/scmplus.go

@@ -0,0 +1,146 @@
+// RTLAMR - An rtl-sdr receiver for smart meters operating in the 900MHz ISM band.
+// Copyright (C) 2015 Douglas Hall
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published
+// by the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package scmplus
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"strconv"
+
+	"github.com/bemasher/rtlamr/crc"
+	"github.com/bemasher/rtlamr/decode"
+	"github.com/bemasher/rtlamr/parse"
+)
+
+func NewPacketConfig(symbolLength int) (cfg decode.PacketConfig) {
+	cfg.CenterFreq = 912600155
+	cfg.DataRate = 32768
+	cfg.SymbolLength = symbolLength
+	cfg.PreambleSymbols = 16
+	cfg.PacketSymbols = 16 * 8
+	cfg.Preamble = "0001011010100011"
+
+	return
+}
+
+type Parser struct {
+	decode.Decoder
+	crc.CRC
+}
+
+func (p Parser) Dec() decode.Decoder {
+	return p.Decoder
+}
+
+func (p Parser) Cfg() decode.PacketConfig {
+	return p.Decoder.Cfg
+}
+
+func NewParser(symbolLength, decimation int) (p Parser) {
+	p.Decoder = decode.NewDecoder(NewPacketConfig(symbolLength), decimation)
+	p.CRC = crc.NewCRC("CCITT", 0xFFFF, 0x1021, 0x1D0F)
+	return
+}
+
+func (p Parser) Parse(indices []int) (msgs []parse.Message) {
+	seen := make(map[string]bool)
+
+	for _, pkt := range p.Decoder.Slice(indices) {
+		s := string(pkt)
+		if seen[s] {
+			continue
+		}
+		seen[s] = true
+
+		data := parse.NewDataFromBytes(pkt)
+
+		// If the checksum fails, bail.
+		if residue := p.Checksum(data.Bytes[2:]); residue != p.Residue {
+			continue
+		}
+
+		scm := NewSCM(data)
+
+		// If the meter id is 0, bail.
+		if scm.EndpointID == 0 {
+			continue
+		}
+
+		msgs = append(msgs, scm)
+	}
+
+	return
+}
+
+// Standard Consumption Message Plus
+type SCM struct {
+	FrameSync    uint16 `xml:",attr"`
+	ProtocolID   uint8  `xml:",attr"`
+	EndpointType uint8  `xml:",attr"`
+	EndpointID   uint32 `xml:",attr"`
+	Consumption  uint32 `xml:",attr"`
+	Tamper       uint16 `xml:",attr"`
+	PacketCRC    uint16 `xml:"Checksum,attr",json:"Checksum"`
+}
+
+func NewSCM(data parse.Data) (scm SCM) {
+	binary.Read(bytes.NewReader(data.Bytes), binary.BigEndian, &scm)
+
+	return
+}
+
+func (scm SCM) MsgType() string {
+	return "SCM+"
+}
+
+func (scm SCM) MeterID() uint32 {
+	return scm.EndpointID
+}
+
+func (scm SCM) MeterType() uint8 {
+	return scm.EndpointType
+}
+
+func (scm SCM) Checksum() []byte {
+	checksum := make([]byte, 2)
+	binary.BigEndian.PutUint16(checksum, scm.PacketCRC)
+	return checksum
+}
+
+func (scm SCM) String() string {
+	return fmt.Sprintf("{ProtocolID:0x%02X EndpointType:0x%02X EndpointID:%10d Consumption:%10d Tamper:0x%04X PacketCRC:0x%04X}",
+		scm.ProtocolID,
+		scm.EndpointType,
+		scm.EndpointID,
+		scm.Consumption,
+		scm.Tamper,
+		scm.PacketCRC,
+	)
+}
+
+func (scm SCM) Record() (r []string) {
+	r = append(r, "0x"+strconv.FormatUint(uint64(scm.FrameSync), 16))
+	r = append(r, "0x"+strconv.FormatUint(uint64(scm.ProtocolID), 16))
+	r = append(r, "0x"+strconv.FormatUint(uint64(scm.EndpointType), 16))
+	r = append(r, strconv.FormatUint(uint64(scm.EndpointID), 10))
+	r = append(r, strconv.FormatUint(uint64(scm.Consumption), 10))
+	r = append(r, "0x"+strconv.FormatUint(uint64(scm.Tamper), 16))
+	r = append(r, "0x"+strconv.FormatUint(uint64(scm.PacketCRC), 16))
+
+	return
+}