The requestDevice()
method of the USB
interface returns a Promise
that resolves with an instance of USBDevice
if the specified device is found. Calling this function triggers the user agent's pairing flow.
USB.requestDevice([filters])
A Promise
that resolves with an instance of USBDevice
.
The following example looks for one of two USB devices. Notice that two product IDs are specified. Both are passed to requestDevice()
. This triggers a user-agent flow that prompts the user to select a device for pairing. Only the selected device is passed to then()
.
The number of filters does not specify the number of devices shown by the user agent. For example, if only a USB device with product ID 0xa800
is found, then only one device will be listed by the user agent. On the other hand if the user agent finds two of the first listed device and one of the second, then all three devices will be listed.
const filters = [
{vendorId: 0x1209, productId: 0xa800},
{vendorId: 0x1209, productId: 0xa850}
];
navigator.usb.requestDevice({filters: filters})
.then(usbDevice => {
console.log("Product name: " + usbDevice.productName);
})
.catch(e => {
console.log("There is no device. " + e);
});