bluetooth with fake data.

2026-05-27 00:36:06 +02:00
parent 0a48932baa
commit b5b3610b70
3 changed files with 132 additions and 3 deletions
@@ -1,12 +1,16 @@
 package main

 import (
+	"encoding/binary"
 	"fmt"
+	"os/exec"
+	"time"

 	"github.com/google/gousb"
+	"tinygo.org/x/bluetooth"
 )

-func main() {
+func oldMain() {

 	var vendorId gousb.ID = 0x0fcf
 	var productId gousb.ID = 0x1008
@@ -16,3 +20,69 @@ func main() {

 	fmt.Println("channel closed")
 }
+
+var adapter = bluetooth.DefaultAdapter
+
+func main() {
+	exec.Command("hciconfig", "hci0", "down").Run()
+	exec.Command("hciconfig", "hci0", "up").Run()
+
+	must(adapter.Enable())
+
+	var powerChar bluetooth.Characteristic
+
+	must(adapter.AddService(&bluetooth.Service{
+		UUID: bluetooth.New16BitUUID(0x1818),
+		Characteristics: []bluetooth.CharacteristicConfig{
+			{
+				UUID:  bluetooth.New16BitUUID(0x2A65), // Cycling Power Feature
+				Flags: bluetooth.CharacteristicReadPermission,
+				Value: []byte{0, 0, 0, 0},
+			},
+			{
+				UUID:   bluetooth.New16BitUUID(0x2A63), // Cycling Power Measurement
+				Flags:  bluetooth.CharacteristicNotifyPermission,
+				Handle: &powerChar,
+			},
+		},
+	}))
+
+	must(adapter.DefaultAdvertisement().Configure(bluetooth.AdvertisementOptions{
+		LocalName:    "LinuxAntBtBridge",
+		ServiceUUIDs: []bluetooth.UUID{bluetooth.New16BitUUID(0x1818)},
+	}))
+	must(adapter.DefaultAdvertisement().Start())
+	fmt.Println("BLE advertising...")
+	var crankRevs uint16
+	var lastCrankEventTime uint16
+
+	for {
+		sec := time.Now().Second()
+		watts := uint16(100 + sec)
+		rpm := uint16(50 + sec)
+
+		// advance crank event time based on rpm
+		// time between crank events = 1024*60/rpm ticks
+		crankEventInterval := uint16(1024 * 60 / rpm)
+		lastCrankEventTime += crankEventInterval
+		crankRevs++
+
+		// flags: bit 5 = crank revolution data present
+		payload := make([]byte, 8)
+		binary.LittleEndian.PutUint16(payload[0:], 0x20)
+		binary.LittleEndian.PutUint16(payload[2:], watts)
+		binary.LittleEndian.PutUint16(payload[4:], crankRevs)
+		binary.LittleEndian.PutUint16(payload[6:], lastCrankEventTime)
+
+		powerChar.Write(payload)
+		fmt.Printf("watts: %d  rpm: %d  crankRevs: %d  eventTime: %d\n", watts, rpm, crankRevs, lastCrankEventTime)
+
+		time.Sleep(time.Second)
+	}
+}
+
+func must(err error) {
+	if err != nil {
+		panic(err)
+	}
+}