This DroidScript (JavaScript for Android) makes my China Bluetooth Bracelet Vibrate whenever I want.

MakeBraceletRingWithDroidScript

var btn;
var bt;
var txt;
//Called when application is started.
function OnStart()
{
    //Create a layout with objects vertically centered.
    lay = app.CreateLayout( "linear", "VCenter,FillXY" );    

    //Create a button 1/3 of screen width and 1/4 screen height.
    btn = app.CreateButton( "Connect", 0.4, 0.15 );
    btn.SetOnTouch( btn_OnTouch );
    lay.AddChild( btn );
    app.AddLayout( lay );
    app.Vibrate("0,100");
    txt = app.CreateText( "Bluetooth", 0.8, 0.2, "Multiline" );
    lay.AddChild( txt );
    
}

var lines = [];
function log(text)
{
    lines.push(text);
    while (lines.length > 5)
    {
        lines.shift();
    }
    var line = "";
    for (var i in lines)
    {
        line += lines[i]+"\n";
    }
    txt.SetText(line);
}

function send(cmd)
{
    bt.Write(String.fromCharCode(13)+String.fromCharCode(10)+cmd+String.fromCharCode(13)+String.fromCharCode(10));
    log("> "+cmd);
}
    

var connected = 0;
channel = 0;
//Called when user touches the button.
function btn_OnTouch() 
{

    if (connected == 0)
    {
      txt.SetText("");
      log("connecting...");
      //Create Bluetooth serial object.
      bt = app.CreateBluetoothSerial();
      bt.SetOnConnect( bt_OnConnect )
      bt.SetOnReceive( bt_OnReceive );
      //bt.SetSplitMode( "End", "\r" );
      bt.Connect("BRACELET",channel);//"00:19:04:0C:78:5F" "0000110800001000800000805F9B34FB");
    }
    else
    {
        send("RING");
    }
}

//Called when we are connected.
function bt_OnConnect( ok)
{
    if( ok )
    {
      log("connected."+channel);
      connected = 1;
      btn.SetText("RING");
    }
    else
    {
      log( "Failed to connect!" );
      bt.Disconnect();
      channel++;
    }
}

function bt_OnReceiveLine(line)
{
    log("< "+line);
    if (line.indexOf("BRSF") >= 0)
    {
        send("+BRSF:0");
        send("OK");
    }
    if (line.indexOf("CIND=") >= 0)
    {
        send("+CIND: (\"service\",(0,1)),(\"call\",(0,1))");
        send("OK");
    }
    if (line.indexOf("CIND?") >= 0)
    {
        send("+CIND: 1,0");
        send("OK");
    }
    if (line.indexOf("CMER") >= 0)
    {
        send("OK");
    }
    if (line.indexOf("CHLD=?") >= 0)
    {
        send("+CHLD: 0");
        send("OK");
    }
}

var buf = "";
//Called when we get data from device.
function bt_OnReceive( data )
{
    if (data === "\r" || data == "\n" || data == "")
    {
        bt_OnReceiveLine(buf);
        buf = "";
    }
    else
    {
        buf += data;
    }
    
}

android java version
https://gist.github.com/shimondoodkin/a582d910045ab06ab68c