WebUSB API, for pushing commands/configuration to the device through webApp

Question

I am doing some research on the WebUSB API for our company because we are going to start to manufacture devices in house.

Our current device manufacture comes with an application so the team can plug the device into a computer and diagnose it. Their application allows us to read outputs from the device, as well as pushing commands/configuration to the device over a wired connection.

Since this device is 100% ours, we are also responsible for building out the diagnostic tooling. We need some sort of interface that allows a user to read outputs and send commands/configuration to the device over a wired USB connection.

Is the webUSB the correct API? If not, what are some suggestions for accomplishing the requirement? Are we limited to building some sort of desktop or mobile application?

Answer 1

I would recommend resources below to read to help you understand if the WebUSB API fits your needs or not:

• https://web.dev/devices-introduction/ helps you pick the appropriate API to communicate with a hardware device of your choice.
• https://web.dev/build-for-webusb/ explains how to build a device to take full advantage of the WebUSB API.

Answer 2

From what you describe, WebUSB isn't strictly required but won't hurt either.

First and foremost, you will need to implement the USB interfaces reading data and sending configurations. It will be a custom protocol, and not one of the standard USB device classes such as HID, video or mass storage. The details of the protocol and if you use control, interrupt or bulk transfers is your choice.

I'm assuming you will connect the devices to Windows PCs, and you likely don't want to put money into writing device drivers. If so, the easiest approach is to add the required descriptors and control requests required for Microsoft OS 2.0 Descriptors. That way, the WinUSB driver will be installed automatically when the device is plugged in.

Using the WinUSB API, a Windows application will then be able to communicate with the USB device. No additional drivers are needed. (On macOS and Linux it's even easier as you don't need the Microsoft OS 2.0 Descriptors in the first place.)

On top of that you can implement the additional descriptors and control requests for WebUSB. It will provide the additional benefit that you can write a web application (instead of a native application) for communicating with the USB device. (Currently, you are restricted to the Chrome browser.) WebUSB devices should implement the WinUSB descriptors as the alternative (.INF files, manual installation process) is a pain.

The already mentioned web page https://web.dev/build-for-webusb/ is a complete example of how to implement it.