diff --git a/README.md b/README.md
index 83187fa..63e71f8 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,41 @@
 # rtldavis
 
-## rtldavis
+## About this Repository
+
+This fork (mdickers47/rtldavis) is a fork of
+[http://github.com/lheijst/rtldavis].  The way the lheijst and bemasher
+versions work is that they implement the Davis frequency hopping,
+demodulate the packets, and dump them to the log file as hex bytes.
+Something else has to decode the messages to create weather data.
+Luc wrote [https://github.com/lheijst/weewx-rtldavis](weewx-rtldavis)
+which is in Python and operates as a weewx driver to update a weewx
+database.
+
+My change is that I have adapted the packet parsing code from
+weewx-rtldavis into the go binary.  You can now write the decoded weather
+data to stdout with the option `-g -`.  It will be written as one data
+point per line, where each data point is three columns, which are metric
+name, value, and UNIX timestamp:
 
-### About this Repository
+```
+wx.davis.windspeed_raw 0 1703133526
+wx.davis.winddir 143.74 1703133526
+wx.davis.windspeed 0.00 1703133526
+wx.davis.temp 50.20 1703133526
+```
+
+This is the Graphite/Carbon "line receiver" format.  If you specify
+`-g server:udpport`, this rtldavis binary will send the data directly
+to Graphite via UDP packets.
+
+*Beware* that I have only implemented the parsing for the Vantage Vue
+ISS sensor package with the 0.2 inch rain bucket, because that is what
+I have.  If the `-g` option is used with a different weather station,
+it will be wrong.
+
+- 2023-12-19 M. Dickerson
+
+From here on is the README from lheijst/rtldavis.
 
 This repository is a fork of [https://github.com/bemasher/rtldavis](https://github.com/bemasher/rtldavis) for use with custom receiver modules. It has been modified in numerous ways.
 1) Added EU frequencies
diff --git a/main.go b/main.go
index a864d0c..6cc73ae 100644
--- a/main.go
+++ b/main.go
@@ -33,17 +33,19 @@
 package main
 
 import (
+    "bytes"
     "flag"
     "io"
     "log"
     "math/rand"
+    "net"
     "os"
     "os/signal"
     "time"
     "strconv"
     "fmt"
 
-    "github.com/lheijst/rtldavis/protocol"
+    "github.com/mdickers47/rtldavis/protocol"
     "github.com/jpoirier/gortlsdr"
 )
 const maxTr = 8
@@ -60,7 +62,8 @@ var (
     verbose           *bool          // -v = emit verbose debug messages
     disableAfc        *bool          // -noafc = disable any automatic corrections
     deviceString      *string        // -d = device serial number or device index
-
+    graphiteSrv       *string        // -gs = decode the packets and send to graphite
+    graphitePrefix    *string        // -gp = prefix for graphite metrics
     // general
     actChan           [maxTr]int     // list with actual channels (0-7); 
                                      //   next values are zero (non-meaning)
@@ -120,7 +123,7 @@ var (
 
 
 func init() {
-    VERSION := "0.15"
+    VERSION := "0.15.2md"
 var (
     tr      int
     mask    int
@@ -148,6 +151,8 @@ var (
     verbose = flag.Bool("v", false, "emit verbose debug messages")
     disableAfc = flag.Bool("noafc", false, "disable any AFC")
     deviceString = flag.String("d","0","device serial number or device index")
+    graphiteSrv = flag.String("gs", "", "decode packets and send to graphite server")
+    graphitePrefix = flag.String("gp", "wx.davis.", "prefix for graphite metrics")
 
     flag.Parse()
     protocol.Verbose = *verbose
@@ -295,6 +300,15 @@ func main() {
         }
     }()
 
+    var graphiteChan chan []string
+    if *graphiteSrv != "" {
+        graphiteChan = make(chan []string)
+        go sendToGraphite(*graphiteSrv, *graphitePrefix, graphiteChan)
+        defer close(graphiteChan)
+    } else {
+        graphiteSrv = nil
+    }
+
     defer func() {
         in.Close()
         out.Close()
@@ -430,7 +444,9 @@ func main() {
                         if *undefined {
                             log.Printf("%02X %d %d %d %d %d msg.ID=%d undefined:%d", 
                                 msg.Data, chTotMsgs[0], chTotMsgs[1], chTotMsgs[2], chTotMsgs[3], totInit, msg.ID, idUndefs)
-                        } else {
+                        } else if graphiteSrv != nil {
+                            graphiteChan <- protocol.DecodeMsg(msg)
+												} else {
                             log.Printf("%02X %d %d %d %d %d msg.ID=%d", 
                                 msg.Data, chTotMsgs[0], chTotMsgs[1], chTotMsgs[2], chTotMsgs[3], totInit, msg.ID) 
                         }
@@ -489,3 +505,33 @@ func Min(values []int64) (ptr int) {
     }
     return ptr
 }
+
+func sendToGraphite(server string, prefix string, graphiteChan chan[]string) {
+  var conn io.Writer
+	var err error
+	if server == "-" {
+		conn = os.Stdout
+	} else {
+		conn, err = net.Dial("udp", server)
+		if err != nil {
+			log.Printf("failed to open %s: %s", server, err)
+			os.Exit(1)
+			return
+		}
+	}
+  log.Printf("connected to %s for graphite output", server)
+	for msgs := range graphiteChan {
+		/* note that every call to conn.write generates a udp packet; the
+		   least we can do is bundle the messages that all arrive
+		   together */
+		var b bytes.Buffer
+		for _, line := range msgs {
+			fmt.Fprintf(&b, "%s%s %d\n", prefix, line, time.Now().Unix())
+		}
+		_, err = b.WriteTo(conn)
+		if err != nil {
+			log.Printf("failed to write to %s: %s", server, err)
+			os.Exit(1)
+		}
+	}
+}
diff --git a/protocol/decode.go b/protocol/decode.go
new file mode 100644
index 0000000..6e7fe4a
--- /dev/null
+++ b/protocol/decode.go
@@ -0,0 +1,243 @@
+/*
+   This module decodes the binary data packets into weather messages.
+   Every packet carries one byte for wind speed, one byte for wind
+   direction, and one other sensor reading of 10 or more bits, labeled by
+   a message identifier.
+
+   The code is adapted from the weewx driver named weewx-rtldavis,
+   written by Luc Heijst (also the author of the upstream fork of
+   rtldavis):
+
+   https://github.com/lheijst/weewx-rtldavis
+
+   If a bug here is also present in the weewx-rtldavis reference code,
+   it should be fixed in both places.  If it is only in this code,
+   then it was introduced by me when translating from Python to Go.
+
+   2023-12-19 M. Dickerson <pomonamikey@gmail.com>
+*/
+
+package protocol
+
+import (
+	"fmt"
+	"log"
+)
+
+func DecodeMsg(m Message) (obs []string) {
+	/* sensor messages arrive with 'channel' numbers, which has no
+	   relation to a go chan or an RF frequency. we only understand the
+	   ISS ('integrated sensor suite') channel 0, used by Vantage Vue. */
+	if m.ID != 0 {
+		log.Printf("received message for unsupported channel %d", m.ID)
+		return
+	}
+
+	windspeed_raw := m.Data[1]
+	obs = append(obs, fmt.Sprintf("windspeed_raw %d", windspeed_raw))
+
+	winddir_vue := float64(m.Data[2])*1.40625 + 0.3
+	obs = append(obs, fmt.Sprintf("winddir %.2f", winddir_vue))
+
+	/* apply the error correction table that might not even be for the
+	   Vantage Vue; it's unclear */
+	winddir := CorrectWindspeed(m.Data[1], m.Data[2])
+	obs = append(obs, fmt.Sprintf("windspeed %.2f", winddir))
+
+	msg_type := (m.Data[0] >> 4) & 0x0F
+	/* most of the time we will use the 10-bit number in this weird place */
+	raw := ((int16(m.Data[3]) << 2) + int16(m.Data[4])>>6) & 0x03FF
+	switch msg_type {
+	case 0x02:
+		/* supercap voltage */
+		obs = append(obs, fmt.Sprintf("supercap_v_raw %d", raw))
+		if raw != 0x03FF {
+			obs = append(obs, fmt.Sprintf("supercap_v %0.2f", float32(raw)/300.0))
+		}
+	case 0x04:
+		/* UV radiation */
+		obs = append(obs, fmt.Sprintf("uv_raw %d", raw))
+		if raw != 0x03FF {
+			obs = append(obs, fmt.Sprintf("uv %0.2f", raw/50.0))
+		}
+	case 0x05:
+		/* rain rate */
+		time_between_tips_raw := ((int16(m.Data[4]) & 0x30) << 4) + int16(m.Data[3])
+		rain_rate := 0.0
+		if time_between_tips_raw == 0x03FF {
+			rain_rate = 0.0 /* time between tips is infinity => no rain */
+		} else if m.Data[4]&0x40 == 0 {
+			/* "heavy rain", time-between-tips is scaled up by 4 bits */
+			/* TODO: we are assuming the 0.01 inch (=0.254mm) size bucket */
+			rain_rate = 3600.0 / (float64(time_between_tips_raw) / 16.0) * 0.254
+		} else {
+			/* "light rain" formula */
+			rain_rate = 3600.0 / float64(time_between_tips_raw) * 0.254
+		}
+		obs = append(obs, fmt.Sprintf("rain_rate_mmh %.2f", rain_rate))
+	case 0x06:
+		/* solar radiation */
+		if raw < 0x03fE {
+			sr := float64(raw) * 1.757936
+			obs = append(obs, fmt.Sprintf("solar_radiation %.2f", sr))
+		}
+	case 0x07:
+		/* solar panel output */
+		if raw != 0x03FF {
+			obs = append(obs, fmt.Sprintf("solar_panel_v %.2f", float32(raw)/300.0))
+		}
+	case 0x08:
+		/* temperature */
+		raw = (int16(m.Data[3]) << 4) + (int16(m.Data[4]) >> 4)
+		if raw != 0x0FFC {
+			if m.Data[4]&0x08 != 0 {
+				/* digital sensor */
+				obs = append(obs, fmt.Sprintf("temp %.2f", float32(raw)/10.0))
+			} else {
+				/* TODO: thermistor */
+				log.Printf("can't interpret analog temperature sensor reading %d", raw)
+				obs = append(obs, fmt.Sprintf("temp_raw %d", raw))
+			}
+		}
+	case 0x09:
+		/* 10-min average wind gust */
+		gust_raw := m.Data[3]
+		gust_index := m.Data[5] >> 4 /* ??? */
+		obs = append(obs, fmt.Sprintf("gust_mph %d", gust_raw))
+		obs = append(obs, fmt.Sprintf("gust_index %d", gust_index))
+	case 0x0a:
+		/* humidity */
+		raw = (int16(m.Data[4]>>4) << 8) + int16(m.Data[3])
+		if raw != 0 {
+			if m.Data[4]&0x08 != 0 {
+				/* digital sensor */
+				obs = append(obs, fmt.Sprintf("humidity %.2f", float32(raw)/10.0))
+			} else {
+				/* TODO: two other types of digital sensor and one analog */
+				log.Printf("can't interpret humidity sensor reading %d", raw)
+				obs = append(obs, fmt.Sprintf("humidity_raw %d", raw))
+			}
+		}
+	case 0x0e:
+		/* rain */
+		raw = int16(m.Data[3]) /* "rain count raw"?? */
+		/* ignore the high bit because apparently some counters wrap at
+		   128 and others at 256, and it doesn't matter */
+		if raw != 0x80 {
+			raw &= 0x7f
+			obs = append(obs, fmt.Sprintf("rain_count %d", raw))
+		}
+	default:
+		log.Printf("Unknown data packet type 0x%02x: %02x", m.ID, m.Data)
+	}
+	return
+}
+
+/* this table is from github.com/lheijst/weewx-rtldavis.  It says the
+   offsets were determined by feeding constructed packets to a Davis
+   Envoy and reading the serial output packets.
+
+   Columns are wind direction, rows are windspeed.
+*/
+
+var wind_offsets = [55][35]int16{
+	{0, 1, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76, 80, 84, 88, 92, 96, 100, 104, 108, 112, 116, 120, 124, 127, 128},
+	{1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+	{2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+	{3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0},
+	{4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0},
+	{5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0},
+	{6, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0},
+	{7, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 0, 0},
+	{8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 0, 0},
+	{9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 0, 0},
+	{10, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 0, 0},
+	{11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 0, 0},
+	{12, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 0, 0},
+	{13, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 3, 1, 0, 0},
+	{14, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 3, 1, 0, 0},
+	{15, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 3, 1, 0, 0},
+	{16, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 3, 1, 0, 0},
+	{17, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 3, 1, 0, 0},
+	{18, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 3, 1, 0, 0},
+	{19, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 4, 4, 1, 0, 0},
+	{20, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 3, 4, 4, 2, 0, 0},
+	{21, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 3, 4, 4, 2, 0, 0},
+	{22, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 3, 4, 4, 2, 0, 0},
+	{23, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 3, 4, 4, 2, 0, 0},
+	{24, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 2, 3, 4, 4, 2, 0, 0},
+	{25, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 2, 3, 4, 4, 2, 0, 0},
+	{26, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 2, 3, 5, 4, 2, 0, 0},
+	{27, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 2, 3, 5, 5, 2, 0, 0},
+	{28, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 2, 3, 5, 5, 2, 0, 0},
+	{29, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 2, 3, 5, 5, 2, 0, 0},
+	{30, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 2, 3, 5, 5, 2, 0, 0},
+	{35, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 2, 4, 6, 5, 2, 0, -1},
+	{40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 2, 4, 6, 6, 2, 0, -1},
+	{45, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 2, 4, 7, 6, 2, -1, -1},
+	{50, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 2, 5, 7, 7, 2, -1, -2},
+	{55, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 2, 5, 8, 7, 2, -1, -2},
+	{60, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 2, 5, 8, 8, 2, -1, -2},
+	{65, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 2, 5, 9, 8, 2, -2, -3},
+	{70, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 0, 2, 5, 9, 9, 2, -2, -3},
+	{75, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 0, 2, 6, 10, 9, 2, -2, -3},
+	{80, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 0, 2, 6, 10, 10, 2, -2, -3},
+	{85, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 0, 2, 7, 11, 11, 2, -3, -4},
+	{90, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 2, 7, 12, 11, 2, -3, -4},
+	{95, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 2, 3, 2, 2, 2, 1, 1, 1, 1, 2, 7, 12, 12, 3, -3, -4},
+	{100, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 3, 3, 2, 2, 2, 1, 1, 1, 1, 2, 8, 13, 12, 3, -3, -4},
+	{105, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 3, 3, 3, 3, 3, 2, 2, 2, 1, 1, 1, 2, 8, 13, 13, 3, -3, -4},
+	{110, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 3, 3, 3, 3, 3, 2, 2, 2, 1, 1, 1, 2, 8, 14, 14, 3, -3, -5},
+	{115, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 2, 3, 3, 3, 3, 3, 2, 2, 2, 1, 1, 1, 2, 9, 15, 14, 3, -3, -5},
+	{120, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 2, 3, 3, 3, 3, 3, 2, 2, 2, 1, 1, 1, 3, 9, 15, 15, 3, -4, -5},
+	{125, 1, 1, 2, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 3, 3, 3, 3, 3, 2, 2, 1, 1, 1, 3, 10, 16, 16, 3, -4, -5},
+	{130, 1, 1, 2, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 1, 1, 3, 10, 17, 16, 3, -4, -6},
+	{135, 1, 2, 2, 1, 1, 0, 0, 0, -1, 0, 0, 1, 1, 2, 2, 3, 3, 3, 3, 4, 3, 3, 2, 2, 2, 1, 1, 3, 10, 17, 17, 4, -4, -6},
+	{140, 1, 2, 2, 1, 1, 0, 0, 0, -1, 0, 0, 1, 1, 2, 2, 3, 3, 3, 4, 4, 3, 3, 2, 2, 2, 1, 1, 3, 11, 18, 17, 4, -4, -6},
+	{145, 2, 2, 2, 1, 1, 0, 0, 0, -1, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 4, 3, 3, 3, 2, 2, 1, 1, 3, 11, 19, 18, 4, -4, -6},
+	{150, 2, 2, 2, 1, 1, 0, 0, -1, -1, 0, 0, 1, 1, 2, 3, 3, 4, 4, 4, 4, 4, 3, 3, 2, 2, 1, 1, 3, 12, 19, 19, 4, -4, -6},
+}
+
+func CorrectWindspeed(s byte, d byte) float32 {
+	/* speed is mph, direction is degrees where 0 = north */
+
+	/* table is treated as having east-west symmetry */
+	if d > 127 {
+		d = byte(256 - int16(d))
+	}
+
+	/* on each axis, find the first term greater than x */
+	row, col := 1, 1
+	for wind_offsets[row][0] <= int16(s) && row < 54 {
+		row++
+	}
+	for wind_offsets[0][col] <= int16(d) && col < 34 {
+		col++
+	}
+
+	corr := float32(wind_offsets[row][col])
+	var delta_s, delta_d float32
+
+	/* we are talking about fractions of a mph at this point, but
+	   nevertheless we soldier on and do a bilinear interpretation to
+	   approximate the corrections where the table does not have an
+	   exact match */
+
+	if col > 1 && wind_offsets[0][col] != int16(d) {
+		d_selected := float32(wind_offsets[0][col])
+		d_prev := float32(wind_offsets[0][col-1])
+		corr_prev := float32(wind_offsets[row][col-1])
+		delta_d = (corr_prev - corr) +
+			(float32(d)-d_prev)/(d_selected-d_prev)*(corr-corr_prev)
+	}
+
+	if row > 1 && wind_offsets[row][0] != int16(s) {
+		s_selected := float32(wind_offsets[row][0])
+		s_prev := float32(wind_offsets[row-1][0])
+		corr_prev := float32(wind_offsets[row-1][col])
+		delta_s = (corr_prev - corr) +
+			(float32(s)-s_prev)/(s_selected-s_prev)*(corr-corr_prev)
+	}
+
+	return float32(s) + corr + delta_d + delta_s
+}
diff --git a/protocol/protocol.go b/protocol/protocol.go
index ff29896..9d03e91 100644
--- a/protocol/protocol.go
+++ b/protocol/protocol.go
@@ -257,7 +257,8 @@ func (p *Parser) Parse(pkts []dsp.Packet) (msgs []Message) {
 
 type Message struct {
 	dsp.Packet
-	ID 	byte
+	ID 	       byte
+	BatteryLow bool
 }
 
 func NewMessage(pkt dsp.Packet) (m Message) {
@@ -265,6 +266,7 @@ func NewMessage(pkt dsp.Packet) (m Message) {
 	m.Data = make([]byte, len(pkt.Data)-2)
 	copy(m.Data, pkt.Data[2:])
 	m.ID = m.Data[0] & 0x7
+	m.BatteryLow = ((m.Data[0] >> 3) & 0x01 == 1)
 	return m
 }