function requestHandler(request, response) {
  try {
      server.log("In request");
    // check if the user sent led as a query parameter
    if ("flag" in request.query) {
      
      if (request.query.flag == "1" || request.query.flag == "0") {
        // convert the led query parameter to an integer
        local flagState = request.query.flag.tointeger();
        device.send("signalStopMotor", flagState); 
      }
    }
    // send a response back saying everything was OK.
    response.send(200, "OK");
  } catch (ex) {
    response.send(500, "Internal Server Error: " + ex);
  }
}
 
// register the HTTP handler
http.onrequest(requestHandler);