The Continuum feature available on devices such as the Lumia 950 brings Windows 10 Mobile devices one step closer to truly being possible PC replacements for general consumers. Another often-overlooked capability that makes Microsoft's smartphones more PC-like is the ability to plug USB devices into them. This feature, called USB On-the-Go, allows portable smart devices to act as a "host" for USB devices, much in the same way standard PCs do. As the Lumia 950 (and predictably its larger sibling the 950 XL) supports this protocol, I took the opportunity to play around with it on my Lumia 950 to see its limitations.
As most of my devices use standard micro-USB plugs, I had to use an adapter to plug them into the Lumia 950's more modern USB Type-C port. These adapters can be had on Amazon for cheap. Some of you may remember seeing this adapter in action in my Actiontec ScreenBeam Mini2 Continuum Edition unboxing and demo (I swear if I ever have to type or say this amazing product's name ever again I'm going to punch someone). As shown off in the video, USB keyboards work just fine, with all the familiar keyboard shortcuts and tricks present and accounted for. I don't have any PS/2 based keyboards on me, so I unfortunately couldn't test those out, but I see no reason why they wouldn't when given the proper adapter.
Same with USB mice, with the familiar Du-dudu-Duh! (I know, shut up) Windows sound effect playing through the Lumia 950's mediocre speakers. USB mice work exactly like you'd expect, with a white pointing cursor popping into the smartphone's screen, highlighting everything it rolls over, and context clicking anything that can be tap-and-holded.
Interestingly, while there is a Mouse section in the Settings panel, it only has the option to change left or right as the primary button. It's bizarre to me that Microsoft would omit the other options given that all elements of the underlying PC architecture are already there. Microsoft got the hard parts out of the way, but it didn't finish the easy stuff. This is actually very problematic when using Continuum, as there's currently no way (to my knowledge) to adjust mouse tracking sensitivity.
USB Microphones like my Yeti USB Microphone work as you'd expect as well, with the hardware mute button found on the microphone itself working to silence all sound recording from being inputted into apps like the generic Voice Recorder.
Devices that require a hefty amount of power to operate (external webcams, for instance), are detected, but don't function, predictably.
Where things get really interesting is with external memory drives. Basic pen drives work as expected, allowing you to access them through the native File Explorer app, as well as target them as destinations for "Save As" functions. The issue, however, is not all of them work. Some work exactly like expected, some will give you a warning saying it may not function correctly (which they don't), and some simply won't register at all. No Du-dudu-Duh!
Some of my flash drives contain a bootable Windows images for installing into fresh PCs. These flash drives are the ones that aren't detected by the phone at all. I could completely understand such formatted drives not working correctly, but I don't understand why the phone doesn't detect them at all.
Another file transfer use-case that didn't work like a PC for me was when connected to my DSLR camera with flash memory inside. When plugging it into my PC, the memory card shows up as removable storage. When plugging into the Lumia 950, I get a warning saying the attached device may not work correctly. I found this one a bit concerning, as the USB OTG specification clearly allows for this.
Things get even more bizarre when attaching to an external hard drive that has its own power supply. The phone detects it just fine, and gives me no warnings, but simply doesn't work. The device never shows up anywhere in the accessible file system.
Now, of course, some of these issues may be specific to some of my particular hardware and may not reflect on other people's devices. However, given what I've experienced, I'm a bit disappointed at how inflexible it turned out to be. The issue isn't that it doesn't work with all my devices; there's no way it'd be fair to expect that. My issue is that what kinds of devices are supposed to work isn't very predictable.
The functionality I've seen so far is great. Unfortunately, in my experience, even with such basic things as external memory, it doesn't seem robust enough to fully obviate the need to carry along a portable PC.
Buy a USB Type-C adapter on Amazon here.