Update help and README

Because there are labels now (eg. 2323=kitchen 3434=piano)

README.md

@@ -120,7 +120,7 @@ The logs will show all signals that the exporter is able to decode, but nothing
     ```
 
 2) Write down all the IDs of sensors you'd like export to Prometheus.
-3) Restart the weather station with those IDs (e.g., `./weather-station 2439 2320`)
+3) Restart the weather station with those IDs and give each ID a human-readable label (e.g., `./weather-station 2439=kitchen 2320=piano`)
 
 ## Dashboards
 

arduino.go

@@ -9,10 +9,11 @@ import (
 	"os"
 
 	"context"
-	"github.com/pkg/errors"
-	"github.com/spf13/afero"
 	"strings"
 	"sync"
+
+	"github.com/pkg/errors"
+	"github.com/spf13/afero"
 )
 
 var (

arduino_test.go

@@ -2,12 +2,13 @@ package main
 
 import (
 	"context"
+	"strings"
+	"testing"
+
 	"github.com/spf13/afero"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
 	"github.com/stretchr/testify/require"
-	"strings"
-	"testing"
 )
 
 var deviceFile = "/dev/ttyUSB0"

main.go

@@ -2,20 +2,22 @@ package main
 
 import (
 	"context"
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promhttp"
-	"gopkg.in/alecthomas/kingpin.v2"
 	"log"
 	"net/http"
 	"strings"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"gopkg.in/alecthomas/kingpin.v2"
 )
 
 var (
 	device = kingpin.Flag("device", "Arduino connected to USB").
 		Default("/dev/ttyUSB0").String()
-	listenAddr = kingpin.Flag("listen-address", "The address to listen on for HTTP requests.").
+	listenAddr = kingpin.Flag("listen-address", "The address to listen on for HTTP requests").
 			Default(":8080").String()
-	ids = kingpin.Arg("ids", "Sensor IDs that will be exported").StringMap()
+	ids = kingpin.Arg("id=label ...", "List of all sensor IDs (e.g. 1234=kitchen 2353=piano)"+
+		" that will be exported to prometheus. Each ID must be given a human-readable label.").StringMap()
 
 	temperature     *prometheus.GaugeVec
 	humidity        *prometheus.GaugeVec

protocol_test.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"testing"
+
 	"github.com/stretchr/testify/assert"
 )
 

pulse.go

@@ -6,12 +6,13 @@ package main
 
 import (
 	"fmt"
-	"github.com/bradfitz/slice"
-	"github.com/pkg/errors"
 	"math"
 	"sort"
 	"strconv"
 	"strings"
+
+	"github.com/bradfitz/slice"
+	"github.com/pkg/errors"
 )
 
 // Signal implements a received 433 MHz signal of compressed raw time series