Relaying USB frames

[io78]

Hello,

There is a particular task I'd like to accomplish, and I have been looking into the nRF52840 to do it. In a nutshell, I want to build a bi-directional relay for USB frames.

For example lets say I have two nRF52840s which I will label A and B. I'd like to do the following:

Keyboard to A (via USB)

A to B (via RF)

B to Laptop (via USB)

In this example the keyboard and laptop should not be aware that A and B exist, that is, both the keyboard and the laptop "think" they are communicating directly with each other; the laptop should recognize the keyboard as an HID device as if the keyboard was plugged in via a USB cable.

Can the nRF52840 accomplish this? If so, is there some particular examples or resources one can refer me to?

Thank you,

[Sigurd]

Hi,

Can the nRF52840 accomplish this?

If I understand you correctly, this is an existing Keyboard that already acts as a USB device. In that case, no. The nRF52840 only supports USB device (USBD). You would need a device that supports both USB device and USB Host to accomplish this. It's the "Keyboard to A (via USB)" that's not supported here, as the keyboard in this scenario already implements a USB device, and you cannot connect a USB device(Keyboard) to another USB device(nRF52840).

[io78]

Is there a similar product offered that can act as a USB host?

[ai212983]

You can use USB Host Shield (most likely with MAX3421E) to connect USB with SPI. I am not aware of products similar to nrf52840 with USB host functionality, and, frankly, not sure it's necessary. 

I am working on something exactly you've described, have both nrf52840 DK and dongle, waiting for Arduino USB Host Shield to arrive. :)