LinLog

The other week I was wondering: can I use my tablet as an external monitor?  I mean, it would be nice to have a portable monitor so I can do dual-display on my laptop wherever I go.  And I usually have my tablet with me.  And it's got a nice 10" display with decent definition.  So why not use it as an extra monitor where I can toss my Slack window or something like that?

Unfortunately, it doesn't seem like there's an out-of-the-box way to do this with my Windows laptop and Galaxy S6 Lite tablet.  But the good news is that there's software that will make it work pretty painlessly.

The solution I ended up going with was Duet.  It's a combination of a desktop app and mobile app working in tandem that works for Windows, Mac, Android, and iOS.  There is a service you can create an account for, but it's not necessary - you can use the apps locally without signing up for anything.  (In fact, I haven't even tried creating an account yet.)  By default Duet connects via a USB connection to your device, but you can also enable an option to connect wirelessly over WiFi.  The WiFi connection is fine, but at least on my network there was a lot of mouse lag when trying to use apps on the tablet.  It's not unusable, but it is unpleasant.  The USB connection is super-responsive, though, so I normally just use that.  As a nice extra, Duet even allows you to use the touchscreen of the tablet, so if your laptop has a touchscreen (which mine does), your secondary screen will work just the same.  Very slick!

The only down side of Duet I've seen so far is that it's not free and there doesn't seem to be a demo version.  There's no cost for the desktop component, but the Android app is about $10.  That's not exactly a fortune, but it's enough to be annoying if you try it and it doesn't work.  Thus my first attempt was with Spacedesk, which is completely free.  However, I didn't actually get a chance to try it out, as the desktop driver install experience was...not great.  For some reason, it took an uncomfortably long to for the installer to run.  Like, after half an hour it was still working.  So I clicked "cancel".  And then, after another hour, the rollback finally completed and I closed the installer.  I have no idea what it was doing, but that was enough to make me not trust it.

Duet, on the other hand, installed fast and worked the first time.  The settings are pretty minimal.  For the connection, you can change the framerate, performance setting, and resolution.  System-wide, you can toggle notifications and "Duet Air", which is what they call the WiFi connection.  To connect the tablet, you pretty much just plug it in.  Duet on the tablet will prompt you to connect the screen and Duet on the laptop will also detect the connection and add the display.  (Of course, if you're using a WiFi connection, it's not that simple.  But it's still pretty simple.)  After that, the tablet just behaves like a regular touchscreen display.  Unfortunately, it only supports one device at a time, so you can't plug in two tablets, or your tablet and your phone, but that's not a huge deal.

So far I'm pretty happy with Duet.  It's a nicely done little utility that "just works" and does a useful thing.  Definitely worth checking out if you have a device that would make a good extra monitor.