gap: stop advertising

Author: ysoldak

examples/stop-advertisement/main.go

@@ -0,0 +1,53 @@
+// This example advertises for 5 minutes after
+// - boot
+// - disconnect
+// and then stops advertising.
+package main
+
+import (
+	"time"
+
+	"tinygo.org/x/bluetooth"
+)
+
+var adapter = bluetooth.DefaultAdapter
+
+var advUntil = time.Now().Add(5 * time.Minute)
+var advState = true
+
+func main() {
+	must("enable BLE stack", adapter.Enable())
+	adv := adapter.DefaultAdvertisement()
+	must("config adv", adv.Configure(bluetooth.AdvertisementOptions{
+		LocalName: "Go Bluetooth",
+	}))
+	adapter.SetConnectHandler(func(device bluetooth.Addresser, connected bool) {
+		if connected {
+			println("connected, not advertising...")
+			advState = false
+		} else {
+			println("disconnected, advertising...")
+			advState = true
+			advUntil = time.Now().Add(5 * time.Minute)
+		}
+	})
+	must("start adv", adv.Start())
+
+	println("advertising...")
+	address, _ := adapter.Address()
+	for {
+		if advState && time.Now().After(advUntil) {
+			println("timeout, not advertising...")
+			advState = false
+			must("stop adv", adv.Stop())
+		}
+		println("Go Bluetooth /", address.MAC.String())
+		time.Sleep(time.Second)
+	}
+}
+
+func must(action string, err error) {
+	if err != nil {
+		panic("failed to " + action + ": " + err.Error())
+	}
+}

gap_linux.go

@@ -4,6 +4,7 @@
 package bluetooth
 
 import (
+	"errors"
 	"strings"
 
 	"github.com/godbus/dbus/v5"
@@ -12,6 +13,8 @@ import (
 	"github.com/muka/go-bluetooth/bluez/profile/device"
 )
 
+var errAdvertisementNotStarted = errors.New("bluetooth: stop advertisement that was not started")
+
 // Address contains a Bluetooth MAC address.
 type Address struct {
 	MACAddress
@@ -22,6 +25,7 @@ type Advertisement struct {
 	adapter       *Adapter
 	advertisement *api.Advertisement
 	properties    *advertising.LEAdvertisement1Properties
+	cancel        func()
 }
 
 // DefaultAdvertisement returns the default advertisement instance but does not
@@ -60,10 +64,20 @@ func (a *Advertisement) Start() error {
 	if a.advertisement != nil {
 		panic("todo: start advertisement a second time")
 	}
-	_, err := api.ExposeAdvertisement(a.adapter.id, a.properties, uint32(a.properties.Timeout))
+	cancel, err := api.ExposeAdvertisement(a.adapter.id, a.properties, uint32(a.properties.Timeout))
 	if err != nil {
 		return err
 	}
+	a.cancel = cancel
+	return nil
+}
+
+// Stop advertisement. May only be called after it has been started.
+func (a *Advertisement) Stop() error {
+	if a.cancel == nil {
+		return errAdvertisementNotStarted
+	}
+	a.cancel()
 	return nil
 }
 

gap_nrf51.go

@@ -64,6 +64,13 @@ func (a *Advertisement) Start() error {
 	return makeError(errCode)
 }
 
+// Stop advertisement.
+func (a *Advertisement) Stop() error {
+	a.isAdvertising.Set(0)
+	errCode := C.sd_ble_gap_adv_stop()
+	return makeError(errCode)
+}
+
 // Low-level version of Start. Used to restart advertisement when a connection
 // is lost.
 func (a *Advertisement) start() uint32 {

gap_nrf528xx-advertisement.go

@@ -81,3 +81,10 @@ func (a *Advertisement) Start() error {
 	errCode := C.sd_ble_gap_adv_start(a.handle, C.BLE_CONN_CFG_TAG_DEFAULT)
 	return makeError(errCode)
 }
+
+// Stop advertisement.
+func (a *Advertisement) Stop() error {
+	a.isAdvertising.Set(0)
+	errCode := C.sd_ble_gap_adv_stop(a.handle)
+	return makeError(errCode)
+}