seprating the ant+ code out.

cmd/bridge/ant.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"io"
+
+	"github.com/google/gousb"
+	"github.com/half2me/antgo/ant"
+	"github.com/half2me/antgo/device"
+	"github.com/half2me/antgo/driver/usb"
+)
+
+func resetAndWait(drv io.ReadWriter) error {
+	if _, err := drv.Write(ant.SystemResetMessage()); err != nil {
+		return err
+	}
+	// drain until we see the startup message (0x6F)
+	for {
+		msg, err := ant.ReadMsg(drv)
+		if err != nil {
+			return err
+		}
+		if msg.Class() == ant.MESSAGE_STARTUP {
+			return nil
+		}
+	}
+}
+
+func listenForAntDevice(vendorId gousb.ID, productId gousb.ID, deviceNumber uint32) {
+	drv, err := usb.GetDevice(vendorId, productId)
+	if err != nil {
+		panic(err)
+	}
+	defer drv.Close()
+
+	fmt.Println("device opened")
+
+	if err := resetAndWait(drv); err != nil {
+		panic(err)
+	}
+	if err := device.StartRxScanModeWait(drv); err != nil {
+		panic(err)
+	}
+	fmt.Println("scan mode started")
+
+	msgs := make(chan ant.BroadcastMessage, 100)
+	go device.DumpBroadcastMessages(context.Background(), drv, msgs)
+
+	fmt.Println("listening...")
+	for msg := range msgs {
+		if msg.DeviceNumber() != deviceNumber {
+			fmt.Printf("Received msg from ignored ant+ device %v\n", msg.DeviceNumber())
+			continue
+		}
+		//fmt.Printf("raw msg: device type=0x%02x device number=%d content=%x\n",
+		//	msg.DeviceType(), msg.DeviceNumber(), msg.Content())
+
+		switch msg.DeviceType() {
+		case ant.DEVICE_TYPE_POWER:
+			cur := ant.PowerMessage(msg)
+			fmt.Printf("%v: power: %dW  cadence: %d rpm\n",
+				msg.DeviceNumber(), cur.InstantaneousPower(), cur.InstantaneousCadence())
+		}
+	}
+}

cmd/bridge/bluetooth.go

@@ -0,0 +1 @@
+package main

cmd/bridge/main.go

@@ -1,63 +1,18 @@
 package main
 
 import (
-	"context"
 	"fmt"
-	"io"
 
-	"github.com/half2me/antgo/ant"
+	"github.com/google/gousb"
-	"github.com/half2me/antgo/device"
-	"github.com/half2me/antgo/driver/usb"
 )
 
-func resetAndWait(drv io.ReadWriter) error {
-	if _, err := drv.Write(ant.SystemResetMessage()); err != nil {
-		return err
-	}
-	// drain until we see the startup message (0x6F)
-	for {
-		msg, err := ant.ReadMsg(drv)
-		if err != nil {
-			return err
-		}
-		if msg.Class() == ant.MESSAGE_STARTUP {
-			return nil
-		}
-	}
-}
-
 func main() {
-	drv, err := usb.GetDevice(0x0fcf, 0x1008)
-	if err != nil {
-		panic(err)
-	}
-	defer drv.Close()
 
-	fmt.Println("device opened")
+	var vendorId gousb.ID = 0x0fcf
+	var productId gousb.ID = 0x1008
+	var deviceNumber uint32 = 3001
 
-	if err := resetAndWait(drv); err != nil {
+	listenForAntDevice(vendorId, productId, deviceNumber)
-		panic(err)
-	}
-	if err := device.StartRxScanModeWait(drv); err != nil {
-		panic(err)
-	}
-	fmt.Println("scan mode started")
-
-	msgs := make(chan ant.BroadcastMessage, 100)
-	go device.DumpBroadcastMessages(context.Background(), drv, msgs)
-
-	fmt.Println("listening...")
-	for msg := range msgs {
-		//fmt.Printf("raw msg: device type=0x%02x device number=%d content=%x\n",
-		//	msg.DeviceType(), msg.DeviceNumber(), msg.Content())
-
-		switch msg.DeviceType() {
-		case ant.DEVICE_TYPE_POWER:
-			cur := ant.PowerMessage(msg)
-			fmt.Printf("%v: power: %dW  cadence: %d rpm\n",
-				msg.DeviceNumber(), cur.InstantaneousPower(), cur.InstantaneousCadence())
-		}
-	}
 
 	fmt.Println("channel closed")
 }