function updateData() { console.log("Fetching Data from ESP..."); var xhttp = new XMLHttpRequest(); xhttp.onreadystatechange = function() { if (this.readyState == 4 && this.status == 200) { console.log("Data:", this.responseText); var values = JSON.parse(this.responseText); document.getElementById("voltage").innerHTML = values.voltage; document.getElementById("current").innerHTML = values.current; document.getElementById("power").innerHTML = values.power; document.getElementById("Ah").innerHTML = values.Ah; document.getElementById("Wh").innerHTML = values.Wh; document.getElementById("battery").innerHTML = values.battery; document.getElementById("run").innerHTML = values.run; } }; xhttp.open("GET", "/meas/values", true); xhttp.send(); } updateData(); window.setInterval(updateData, 3000);