e1e010d8ec
This makes the API a bit more natural and (if needed) allows for a slightly greater precision in specifying the advertisement interval.
105 lines
3.0 KiB
Go
105 lines
3.0 KiB
Go
package main
|
|
|
|
// This example implements a NUS (Nordic UART Service) peripheral.
|
|
// I can't find much official documentation on the protocol, but this can be
|
|
// helpful:
|
|
// https://learn.adafruit.com/introducing-adafruit-ble-bluetooth-low-energy-friend/uart-service
|
|
//
|
|
// Code to interact with a raw terminal is in separate files with build tags.
|
|
|
|
import (
|
|
"time"
|
|
|
|
"github.com/tinygo-org/bluetooth"
|
|
)
|
|
|
|
var (
|
|
serviceUUID = bluetooth.NewUUID([16]byte{0x6E, 0x40, 0x00, 0x01, 0xB5, 0xA3, 0xF3, 0x93, 0xE0, 0xA9, 0xE5, 0x0E, 0x24, 0xDC, 0xCA, 0x9E})
|
|
rxUUID = bluetooth.NewUUID([16]byte{0x6E, 0x40, 0x00, 0x02, 0xB5, 0xA3, 0xF3, 0x93, 0xE0, 0xA9, 0xE5, 0x0E, 0x24, 0xDC, 0xCA, 0x9E})
|
|
txUUID = bluetooth.NewUUID([16]byte{0x6E, 0x40, 0x00, 0x03, 0xB5, 0xA3, 0xF3, 0x93, 0xE0, 0xA9, 0xE5, 0x0E, 0x24, 0xDC, 0xCA, 0x9E})
|
|
)
|
|
|
|
func main() {
|
|
println("starting")
|
|
adapter := bluetooth.DefaultAdapter
|
|
must("enable BLE stack", adapter.Enable())
|
|
adv := adapter.DefaultAdvertisement()
|
|
must("config adv", adv.Configure(bluetooth.AdvertisementOptions{
|
|
LocalName: "NUS", // Nordic UART Service
|
|
ServiceUUIDs: []bluetooth.UUID{serviceUUID},
|
|
Interval: bluetooth.NewAdvertisementInterval(100 * time.Millisecond),
|
|
}))
|
|
must("start adv", adv.Start())
|
|
|
|
var rxChar bluetooth.Characteristic
|
|
var txChar bluetooth.Characteristic
|
|
must("add service", adapter.AddService(&bluetooth.Service{
|
|
UUID: serviceUUID,
|
|
Characteristics: []bluetooth.CharacteristicConfig{
|
|
{
|
|
Handle: &rxChar,
|
|
UUID: rxUUID,
|
|
Flags: bluetooth.CharacteristicWritePermission | bluetooth.CharacteristicWriteWithoutResponsePermission,
|
|
WriteEvent: func(client bluetooth.Connection, offset int, value []byte) {
|
|
for _, c := range value {
|
|
// TODO: echo these characters back.
|
|
putchar(c)
|
|
if c == '\r' {
|
|
putchar('\n')
|
|
}
|
|
}
|
|
},
|
|
},
|
|
{
|
|
Handle: &txChar,
|
|
UUID: txUUID,
|
|
Flags: bluetooth.CharacteristicNotifyPermission | bluetooth.CharacteristicReadPermission,
|
|
},
|
|
},
|
|
}))
|
|
|
|
initTerminal()
|
|
defer restoreTerminal()
|
|
print("NUS console enabled, use Ctrl-X to exit\r\n")
|
|
var line []byte
|
|
for {
|
|
ch := getchar()
|
|
putchar(ch)
|
|
line = append(line, ch)
|
|
|
|
// Send the current line to the central.
|
|
if ch == '\x18' {
|
|
// The user pressed Ctrl-X, exit the terminal.
|
|
break
|
|
} else if ch == '\r' {
|
|
// Send another newline (consoles only seem to receive CR chars).
|
|
putchar('\n')
|
|
line = append(line, '\n')
|
|
|
|
sendbuf := line // copy buffer
|
|
// Reset the slice while keeping the buffer in place.
|
|
line = line[:0]
|
|
|
|
// Send the sendbuf after breaking it up in pieces.
|
|
for len(sendbuf) != 0 {
|
|
// Chop off up to 20 bytes from the sendbuf.
|
|
partlen := 20
|
|
if len(sendbuf) < 20 {
|
|
partlen = len(sendbuf)
|
|
}
|
|
part := sendbuf[:partlen]
|
|
sendbuf = sendbuf[partlen:]
|
|
// This also sends a notification.
|
|
_, err := txChar.Write(part)
|
|
must("send notification", err)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
func must(action string, err error) {
|
|
if err != nil {
|
|
panic("failed to " + action + ": " + err.Error())
|
|
}
|
|
}
|