From bb1b65aed49dfafe65adbe0869a5d13b8802b64f Mon Sep 17 00:00:00 2001 From: Vincent Batts Date: Tue, 31 Oct 2023 09:47:40 -0400 Subject: [PATCH] explorer: adding another sample app Signed-off-by: Vincent Batts --- explorer.go | 166 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 166 insertions(+) create mode 100644 explorer.go diff --git a/explorer.go b/explorer.go new file mode 100644 index 0000000..c7c0834 --- /dev/null +++ b/explorer.go @@ -0,0 +1,166 @@ +// +build + +package main + +import ( + "flag" + "fmt" + "log" + "os" + "strings" + "time" + + "github.com/paypal/gatt" + "github.com/paypal/gatt/examples/option" +) + +var done = make(chan struct{}) + +func onStateChanged(d gatt.Device, s gatt.State) { + fmt.Println("State:", s) + switch s { + case gatt.StatePoweredOn: + fmt.Println("Scanning...") + d.Scan([]gatt.UUID{}, false) + return + default: + d.StopScanning() + } +} + +func onPeriphDiscovered(p gatt.Peripheral, a *gatt.Advertisement, rssi int) { + id := strings.ToUpper(flag.Args()[0]) + if strings.ToUpper(p.ID()) != id { + return + } + + // Stop scanning once we've got the peripheral we're looking for. + p.Device().StopScanning() + + fmt.Printf("\nPeripheral ID:%s, NAME:(%s)\n", p.ID(), p.Name()) + fmt.Println(" Local Name =", a.LocalName) + fmt.Println(" TX Power Level =", a.TxPowerLevel) + fmt.Println(" Manufacturer Data =", a.ManufacturerData) + fmt.Println(" Service Data =", a.ServiceData) + fmt.Println("") + + p.Device().Connect(p) +} + +func onPeriphConnected(p gatt.Peripheral, err error) { + fmt.Println("Connected") + defer p.Device().CancelConnection(p) + + if err := p.SetMTU(500); err != nil { + fmt.Printf("Failed to set MTU, err: %s\n", err) + } + + // Discovery services + ss, err := p.DiscoverServices(nil) + if err != nil { + fmt.Printf("Failed to discover services, err: %s\n", err) + return + } + + for _, s := range ss { + msg := "Service: " + s.UUID().String() + if len(s.Name()) > 0 { + msg += " (" + s.Name() + ")" + } + fmt.Println(msg) + + // Discovery characteristics + cs, err := p.DiscoverCharacteristics(nil, s) + if err != nil { + fmt.Printf("Failed to discover characteristics, err: %s\n", err) + continue + } + + for _, c := range cs { + msg := " Characteristic " + c.UUID().String() + if len(c.Name()) > 0 { + msg += " (" + c.Name() + ")" + } + msg += "\n properties " + c.Properties().String() + fmt.Println(msg) + + // Read the characteristic, if possible. + if (c.Properties() & gatt.CharRead) != 0 { + b, err := p.ReadCharacteristic(c) + if err != nil { + fmt.Printf("Failed to read characteristic, err: %s\n", err) + continue + } + fmt.Printf(" value %x | %q\n", b, b) + } + + // Discovery descriptors + ds, err := p.DiscoverDescriptors(nil, c) + if err != nil { + fmt.Printf("Failed to discover descriptors, err: %s\n", err) + continue + } + + for _, d := range ds { + msg := " Descriptor " + d.UUID().String() + if len(d.Name()) > 0 { + msg += " (" + d.Name() + ")" + } + fmt.Println(msg) + + // Read descriptor (could fail, if it's not readable) + b, err := p.ReadDescriptor(d) + if err != nil { + fmt.Printf("Failed to read descriptor, err: %s\n", err) + continue + } + fmt.Printf(" value %x | %q\n", b, b) + } + + // Subscribe the characteristic, if possible. + if (c.Properties() & (gatt.CharNotify | gatt.CharIndicate)) != 0 { + f := func(c *gatt.Characteristic, b []byte, err error) { + fmt.Printf("notified: % X | %q\n", b, b) + } + if err := p.SetNotifyValue(c, f); err != nil { + fmt.Printf("Failed to subscribe characteristic, err: %s\n", err) + continue + } + } + + } + fmt.Println() + } + + fmt.Printf("Waiting for 5 seconds to get some notifiations, if any.\n") + time.Sleep(5 * time.Second) +} + +func onPeriphDisconnected(p gatt.Peripheral, err error) { + fmt.Println("Disconnected") + close(done) +} + +func main() { + flag.Parse() + if len(flag.Args()) != 1 { + log.Fatalf("usage: %s [options] peripheral-id\n", os.Args[0]) + } + + d, err := gatt.NewDevice(option.DefaultClientOptions...) + if err != nil { + log.Fatalf("Failed to open device, err: %s\n", err) + return + } + + // Register handlers. + d.Handle( + gatt.PeripheralDiscovered(onPeriphDiscovered), + gatt.PeripheralConnected(onPeriphConnected), + gatt.PeripheralDisconnected(onPeriphDisconnected), + ) + + d.Init(onStateChanged) + <-done + fmt.Println("Done") +}