dir-655-network-monitor.js

/**
 * DIR-655 Network Monitor.
 * Based on Network Monitor v2.0 for Yahoo! Widgets.
 */

let lan_tx_bytes;
let lan_rx_bytes;
let last_timestamp;

const readValues = () => {
    fetch('http://192.168.0.1/router_info.xml?section=lan_stats')
    .then((response) => response.text())
    .then((str) => (new DOMParser()).parseFromString(str, 'text/xml'))
    .then(xml => {
        const c_last_timestamp = Date.now();
        const c_lan_tx_bytes = parseInt(xml.querySelector('lan_tx_bytes').textContent);
        const c_lan_rx_bytes = parseInt(xml.querySelector('lan_rx_bytes').textContent);
        if (last_timestamp) {
            const d_last_timestamp = c_last_timestamp - last_timestamp;
            const d_lan_tx_bytes = c_lan_tx_bytes - lan_tx_bytes;
            const d_lan_rx_bytes = c_lan_rx_bytes - lan_rx_bytes;
            const d_lan_tx_Mbytes_ps = (d_lan_tx_bytes * 8 / 1024 / 1024) / (d_last_timestamp / 1000);
            const d_lan_rx_Mbytes_ps = (d_lan_rx_bytes * 8 / 1024 / 1024) / (d_last_timestamp / 1000);
            console.clear();
            console.log(`UL ${d_lan_rx_Mbytes_ps.toFixed(2)} Mbit/s`);
            console.log(`DL ${d_lan_tx_Mbytes_ps.toFixed(2)} Mbit/s`);
        }
        last_timestamp = c_last_timestamp;
        lan_tx_bytes = c_lan_tx_bytes;
        lan_rx_bytes = c_lan_rx_bytes;
    });
};

readValues();
setInterval(readValues, 1000);
console.clear();