ble/README.md

# BLE

A modern, cross-platform Go library for Bluetooth Low Energy

This package is a working but incomplete interface for access to Bluetooth
Low Energy devices. It is intended to support multiple operating systems
with a uniform API. Currently, MacOS and Android are supported. Android
support requires the use of [Gio](https://gioui.org).

The API is asyncrhonous and event driven. To access Bluetooth hardware,
first create a `BLE` variable with `NewBLE()`. On Android, you must also
call `Enable` with a pointer to your Gio Window.

```go
import (
	...
	"git.wow.st/gmp/ble"
	"gioui.org/app"
)

func runloop() {
	b := ble.NewBle()
	w := app.NewWindow()
	b.Enable(w)
	...
```

Once enabled, you can call the primary API functions, `Scan`, `StopScan`,
`Connect`, and `CancelConnection`. You can also query the state of the
Bluetooth hardware by calling `State`.

Calling `Events` on your `BLE` object returns a channel on which API events 
are delivered. These events notify your program when the state of the
BLE hardware changes (e.g. powered on or off), peripherals are connected,
services or characteristics are discovered, or values for characteristics
are updated.

Using Gio, your main event loop will look something like this:

```
	for {
		select {
		case e := <-b.Events():
			switch e := e.(type) {
				// Handle BLE Events
			}
		}
		case e := <-w.Events():
			switch e := e.(type) {
				// Handle Gio events
			}
		}
	}
```

An example heart rate monitor app can be found at [git.wow.st/gmp/hrm](https://git.wow.st/gmp/hrm).