// NewCountChar ...
func NewCountChar() *ble.Characteristic {
n := 0
c := ble.NewCharacteristic(CountCharUUID)
c.HandleRead(ble.ReadHandlerFunc(func(req ble.Request, rsp ble.ResponseWriter) {
fmt.Fprintf(rsp, "count: Read %d", n)
log.Printf("count: Read %d", n)
n++
}))
c.HandleWrite(ble.WriteHandlerFunc(func(req ble.Request, rsp ble.ResponseWriter) {
log.Printf("count: Wrote %s", string(req.Data()))
}))
c.HandleNotify(ble.NotifyHandlerFunc(func(req ble.Request, n ble.Notifier) {
cnt := 0
log.Printf("count: Notification subscribed")
for {
select {
case <-n.Context().Done():
log.Printf("count: Notification unsubscribed")
return
case <-time.After(time.Second):
log.Printf("count: Notify: %d", cnt)
if _, err := fmt.Fprintf(n, "Count: %d", cnt); err != nil {
// Client disconnected prematurely before unsubscription.
log.Printf("count: Failed to notify : %s", err)
return
}
cnt++
}
}
}))
c.HandleIndicate(ble.NotifyHandlerFunc(func(req ble.Request, n ble.Notifier) {
cnt := 0
log.Printf("count: Indication subscribed")
for {
select {
case <-n.Context().Done():
log.Printf("count: Indication unsubscribed")
return
case <-time.After(time.Second):
log.Printf("count: Indicate: %d", cnt)
if _, err := fmt.Fprintf(n, "Count: %d", cnt); err != nil {
// Client disconnected prematurely before unsubscription.
log.Printf("count: Failed to indicate : %s", err)
return
}
cnt++
}
}
}))
return c
}
func newCCCD(c *ble.Characteristic) *ble.Descriptor {
d := ble.NewDescriptor(ble.ClientCharacteristicConfigUUID)
d.HandleRead(ble.ReadHandlerFunc(func(req ble.Request, rsp ble.ResponseWriter) {
cccs := req.Conn().(*conn).cccs
ccc := cccs[c.Handle]
binary.Write(rsp, binary.LittleEndian, ccc)
}))
d.HandleWrite(ble.WriteHandlerFunc(func(req ble.Request, rsp ble.ResponseWriter) {
cn := req.Conn().(*conn)
old := cn.cccs[c.Handle]
ccc := binary.LittleEndian.Uint16(req.Data())
oldNotify := old&cccNotify != 0
oldIndicate := old&cccIndicate != 0
newNotify := ccc&cccNotify != 0
newIndicate := ccc&cccIndicate != 0
if newNotify && !oldNotify {
if c.Property&ble.CharNotify == 0 {
rsp.SetStatus(ble.ErrUnlikely)
return
}
send := func(b []byte) (int, error) { return cn.svr.notify(c.ValueHandle, b) }
cn.nn[c.Handle] = ble.NewNotifier(send)
go c.NotifyHandler.ServeNotify(req, cn.nn[c.Handle])
}
if !newNotify && oldNotify {
cn.nn[c.Handle].Close()
}
if newIndicate && !oldIndicate {
if c.Property&ble.CharIndicate == 0 {
rsp.SetStatus(ble.ErrUnlikely)
return
}
send := func(b []byte) (int, error) { return cn.svr.indicate(c.ValueHandle, b) }
cn.in[c.Handle] = ble.NewNotifier(send)
go c.IndicateHandler.ServeNotify(req, cn.in[c.Handle])
}
if !newIndicate && oldIndicate {
cn.in[c.Handle].Close()
}
cn.cccs[c.Handle] = ccc
}))
return d
}
// NewBatteryService ...
func NewBatteryService() *ble.Service {
lv := byte(100)
s := ble.NewService(ble.UUID16(0x180F))
c := s.NewCharacteristic(ble.UUID16(0x2A19))
c.HandleRead(
ble.ReadHandlerFunc(func(req ble.Request, rsp ble.ResponseWriter) {
rsp.Write([]byte{lv})
lv--
}))
// Characteristic User Description
c.NewDescriptor(ble.UUID16(0x2901)).SetValue([]byte("Battery level between 0 and 100 percent"))
// Characteristic Presentation Format
c.NewDescriptor(ble.UUID16(0x2904)).SetValue([]byte{4, 1, 39, 173, 1, 0, 0})
return s
}