d77521461d
This is a big rewrite to use DBus calls directly instead of going
through go-bluetooth first.
This is a big change, but I believe it is an improvement. While the
go-bluetooth works for many cases, it's a layer in between that I
believe hurts more than it helps. Without it, we can just program
directly against the BlueZ D-Bus API. The end result is about 10% more
code.
With this rewrite, I fixed the following issues:
* All MapToStruct warnings are gone, like in
https://github.com/tinygo-org/bluetooth/issues/193.
* Advertisements can be restarted after they were stopped. Previously
this resulted in a panic.
* Looking at the source code of go-bluetooth, it appears that it
includes devices from a different Bluetooth adapter than the one
that's currently scanning. This is fixed with the rewrite.
* Fix a bug in Adapter.AddService where it would only allow adding a
single service. Multiple services can now be added.
This was actually the motivating bug that led me down to rewrite the
whole thing because I couldn't figure out where the bug was in
go-bluetooth (it's many layers deep).
* The `WriteEvent` callback in a characteristic now also gets the
'offset' parameter which wasn't provided by go-bluetooth.
This rewrite also avoids go-bluetooth specific workarounds like
https://github.com/tinygo-org/bluetooth/pull/74 and
https://github.com/tinygo-org/bluetooth/pull/121.
I have tested all examples in the smoketest-linux Makefile target. They
all still work with this rewrite.
71 lines
1.9 KiB
Go
71 lines
1.9 KiB
Go
//go:build !baremetal
|
|
|
|
// Some documentation for the BlueZ D-Bus interface:
|
|
// https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/doc
|
|
|
|
package bluetooth
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
|
|
"github.com/godbus/dbus/v5"
|
|
)
|
|
|
|
const defaultAdapter = "hci0"
|
|
|
|
type Adapter struct {
|
|
id string
|
|
scanCancelChan chan struct{}
|
|
bus *dbus.Conn
|
|
bluez dbus.BusObject // object at /
|
|
adapter dbus.BusObject // object at /org/bluez/hciX
|
|
address string
|
|
defaultAdvertisement *Advertisement
|
|
|
|
connectHandler func(device Address, connected bool)
|
|
}
|
|
|
|
// DefaultAdapter is the default adapter on the system. On Linux, it is the
|
|
// first adapter available.
|
|
//
|
|
// Make sure to call Enable() before using it to initialize the adapter.
|
|
var DefaultAdapter = &Adapter{
|
|
id: defaultAdapter,
|
|
connectHandler: func(device Address, connected bool) {
|
|
},
|
|
}
|
|
|
|
// Enable configures the BLE stack. It must be called before any
|
|
// Bluetooth-related calls (unless otherwise indicated).
|
|
func (a *Adapter) Enable() (err error) {
|
|
bus, err := dbus.SystemBus()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
a.bus = bus
|
|
a.bluez = a.bus.Object("org.bluez", dbus.ObjectPath("/"))
|
|
a.adapter = a.bus.Object("org.bluez", dbus.ObjectPath("/org/bluez/"+a.id))
|
|
addr, err := a.adapter.GetProperty("org.bluez.Adapter1.Address")
|
|
if err != nil {
|
|
if err, ok := err.(dbus.Error); ok && err.Name == "org.freedesktop.DBus.Error.UnknownObject" {
|
|
return fmt.Errorf("bluetooth: adapter %s does not exist", a.adapter.Path())
|
|
}
|
|
return fmt.Errorf("could not activate BlueZ adapter: %w", err)
|
|
}
|
|
addr.Store(&a.address)
|
|
|
|
return nil
|
|
}
|
|
|
|
func (a *Adapter) Address() (MACAddress, error) {
|
|
if a.address == "" {
|
|
return MACAddress{}, errors.New("adapter not enabled")
|
|
}
|
|
mac, err := ParseMAC(a.address)
|
|
if err != nil {
|
|
return MACAddress{}, err
|
|
}
|
|
return MACAddress{MAC: mac}, nil
|
|
}
|