Reduce refresh of live view to 1s and fix connection status

static/js/BLE.js

@@ -26,7 +26,7 @@ async function connect(props) {
   console.log("> Characteristic value changed event listener added");
   socket = io();
 
-  socket.addEventListener("open", () => {
+  socket.on("connect", () => {
     btn.classList.remove("bg-red-600");
     btn.classList.add("bg-green-600");
   });