WebHID API

const device = await navigator.hid.requestDevice({filters: []})
// A popup titled `... wants to connect to a HID Device` with `Cancel` and `Connect` buttons will show up with a device list to select from.
// Select one and click on `Connect` button. Then the device will be an array with the selected device in it.

let devices = await navigator.hid.getDevices();
devices.forEach(device => {
    console.log(`HID: ${device.productName}`);
});

navigator.hid.addEventListener('disconnect', (event) => {
    console.log(`HID disconnected: ${event.device.productName}`);
    console.dir(event)
});
// For example, when my connected keyboard gets disconnected, the log in the console will show:
// HID disconnected: USB USB Keyboard
// {
//    bubbles: false
//    cancelBubble: false
//    cancelable: false
//    composed: false
//    currentTarget: HID {onconnect: null, ondisconnect: null}
//    defaultPrevented: false
//    device: HIDDevice {oninputreport: null, opened: false, vendorId: 6700, productId: 11555, productName: "USB USB Keyboard", …}
//    eventPhase: 0
//    isTrusted: true
//    path: []
//    returnValue: true
//    srcElement: HID {onconnect: null, ondisconnect: null}
//    target: HID {onconnect: null, ondisconnect: null}
//    timeStamp: 18176.600000023842
//    type: "disconnect"
// }

// The event above is an instance of the HIDConnectionEvent interface.