zlacker

The video capture part should work, but I don't believe they support USB OTG, so they wouldn't be able to impersonate the keyboard.

The official documentation[0] says all Pi devices have USB OTG, but I'm not sure if there's something else about the Pi 4 and Pi Zero W that allows USB gadget mode because I've never found anyone talking about using it before recent generations of Pi. This StackExchange answer says the A and the A+ had it, but that the 2 doesn't.[1]

[0] https://www.raspberrypi.org/documentation/hardware/raspberry... [1] https://raspberrypi.stackexchange.com/questions/71613/how-to...

>>mtlync+(OP)
I'd expect the Pi Zero W to be fast enough to pass through the MJPEG stream and impersonate the keyboard, which should cut the cost by $20+ plus however much you save on not needing a fancy case.

>>Scaevo+P3
Yeah that's true. I stopped thinking about the Pi Zero W early in the project because I assumed it would choke on video encoding. When I discovered that the HDMI dongle was doing the heavy lifting, I forgot to revisit that assumption. I'm going to order an USB to micro-USB adaptor to test it out because it would slim things down significantly.

>>mtlync+(OP)
Any Pi with just one USB port (zero, A, A+, 3A) is capable of USB gadget mode because there is no hub between the SOC and the port.

Those with multiple ports have a hub in between and are not capable of gadget mode.

The pi 4 is an exception, it is capable of gadget mode on its USB-C power input, not via the normal ports as there is a hub in between there too.

>>mtlync+Wd
Woops, forgot the major issue-- the Pi Zero only has one USB port (the other is just for power), so you couldn't get video frames in at the same time as you pretended to be a keyboard.

>>Scaevo+wQ
The Pi Zero's power port is actually a USB OTG port. I used it in my precursor project to forward keystrokes:

https://mtlynch.io/key-mime-pi/

>>mtlync+E21
On the web page you explicitly say to connect it to the port labelled "USB", which is not the power port.

>>magica+DK3
Whoops, you're right. I misremembered. It's power on the Pi 4 and data on the Pi Zero.

Thanks for the correction!