I have a small number of USB serial interfaces connected (a HF transceiver, CW keyer based on Arduino) and two bluetooth ports, that I never use and am not sure where do they come from (probably some application). In my SPA I need to read list of ports to be able to select which one to connect as which function.
However, when I call navigator.serial.getPorts() I always get an empty list. BTW, same for navigator.usb.getDevices() It runs on Chrome version 87.0.4280.141 (Official Build) (64-bit). Serial API is enabled.
How to solve this?
UPDATE: it is invoked from script in HTML file in local filesystem (not served over HTTP)
You need to request the user's permission to read the Serial's ports by first calling navigator.serial.requestPort():
onclick = async () => {
await navigator.serial.requestPort();
console.log( await navigator.serial.getPorts() );
};