The SonarPen was launched through Kickstarter in 2018.  It was primarily designed for iOS and Android smartphones and tablets as a cheap alternative to the expensive styli like the Apple Pencil. 

We actually have been in contact with  SonarPen's creator Elton Leung since 2018.   We were hoping they can add Windows support ever since. To date, there's still no Windows driver but thanks to the support from SpaceDesk, we can now use it for Windows apps too.

SpaceDesk is a software tool that allows a host machine to use other machines like tablets as its monitors.  Their ability to build a monitor wall is amazing. Recently they added support for relaying pen input too, so it's possible to use SpaceDesk as a wireless Pen Display. With SpaceDesk, we're now able to use SonarPen on Windows apps, including our Expresii that features beautiful organic digital watercolor. 

Previously, we tried   Easy Canvas Pro  (US$5 / year) and   SuperDisplay   (US$10 one time)   for Pen-Display application. Currently, we think SuperDisplay  gives the best performance among the three.  SuperDisplay  does support pen tilt, which is quite important for our app Expresii.   SpaceDesk doesn't support pen tilt nor  multi-touch gestures yet. SpaceDesk is currently free to use, while they also offer a Business license. Our current recommendation is still   SuperDisplay, which is the fastest, the most feature-complete and is inexpensive.   We look forward to SuperDisplay supporting the SonarPen.

2021.05.06 Update:  you can use USB tethering for faster connection on SpaceDesk.

What can still be added: ​It'd be great  if any of these programs can relay accelerometer/orientation sensor  readings and act as a G-Sensor  of Windows tablets so that we can directly control paper tilt in Expresii to direct the paint flow. Using other apps like  Sensor stream IMU+GPS  alongside is no good, as only one  app can be in the foreground and nowadays smartphones would have background apps dormant  after a few moments. We've tried putting the app in Battery Saving Exception or disable Battery  Optimization (on Android 9) but to no vain.

In the above video, we also show the new features of  Brush Tilt Control Pad    and   Auto Settle Timer:

You can now stack paint in the same layer by settling paint. We've also added a timer for auto-settling. You can try these new features in a beta version of Expresii, which you can enable by selecting beta option in the System>Advanced tab. Please let us know how you like them.

Apart from Duet Display  Pro,  there's also Easy Canvas Pro from DEVGURU Co.  in   Korea that allows you to use your iOS or Android device as pen display to your desktop apps.  Yes, it's like connecting a Cintiq to your desktop, but you have the option to go either wired or wireless.  You can use a tablet like   the iPad or  the   Samsung Tab S3   or even your Samsung Note 10 phone.  It'd be  a great solution if you already own one of those devices.

We just tested  their newly released   EasyCanvas Pro for Android . I own a Samsung Note 8 with S Pen, which supports both pressure and tilt, so I used it in this test.  Normally, you should use a tablet instead since a phone's screen is very small for painting.

I found the wired connection gives satisfactory performance. When using 2.4GHz wifi, the delay is rather noticeable.   Unfortunately, I don't have a 5GHz router here so I can't test 5GHz   performance. The Samsung device shows the 2.4GHz wifi  giving 144Mbps, while my test desktop is connected to the wireless router via cable.  My desktop screen is at 4k and my phone is set at FHD+, so Easy Canvas has to resample the 4k screen capture and that's another source of latency.   

We hope DEVGURU can support G-Sensor data and hover in the future.   G-Sensor can be used for surface tilt to direct the paint flow, and hover is good for users to see the pen posture before hitting the paper. This is important for Eastern calligraphy, if not for painting in general.

Keyboard  are good for shortcuts, but sometimes we prefer to use a knob for more intuitive and smoother operation. The Surface Dial  ($100) was designed for such a purpose. However, the Surface Dial doesn't lend itself to muscle memory - the only operations are rotate and press so you need to rely on mode change in order to invoke more than 3 actions. That's why people like compact controllers with more buttons like the TourBox  ($158 at Amazon)  or the Clip studio TabMate    ($57) so that they can control more parameters   swiftly  without worrying about which mode they're in.

Controllers like TourBox are great to use but a bit expensive. Any alternatives that are less expensive but still give us a dial? 

We found  numerous USB volume controllers on the market. Among them, devices from iwit caught our attention  since their inexpensive knobs can actually be programmed to send custom keystrokes. They can even simulate a Surface Dial! This is a Chinese company in Beijing and they sell in Taobao (from $10)  for the Chinese market but various resellers are reselling them at Amazon or EBay (big version available at e.g. as this item at  Amazon for $31, small version at EBay for $20, big or small at Aliexpress for $20-$30).  The two we got are small ones.

The weight is just right and together with the non-skid pad it doesn't move around.  The knob on the silver one was not level when it arrived, but we managed to pull the knob out and after plugging it back it stayed leveled.   The design is simple and the knob clicks and rotates well making   It almost a fidget toy.   ​∠( ᐛ 」∠)＿ The iWit dials are notched so they don't rotate as smoothly as the Surface Dial.  They are also smaller and don't have a indention like the Shuttle Express   ($60)  does making them less suited for one-finger operation.

Programmability is not advertised but it is there.   I chatted with the seller at Taobao, who said they don't want to advertise it to avoid the trouble of providing customer support.   Why?  They said their way to program the device  can be confusing so they would rather just sell it as a simple, single-purpose USB volume controller.   ¯\_(ツ)_/¯

How to Program. The way  you program them is special. You use the app Notepad as the  display and let the device print a menu that you can choose from.  Make sure you use   EN_US keyboard layout for this.   To enter setup mode, press the iwit dial while you plug it to a computer via USB.  You should have Notepad already open and in focus when you do this so that Notepad receives all the key output from the iwit.   The rest is simply to navigate the menu with the dial itself. Each can be programmed to give different keystrokes independent of each other and thus you can connect multiple iwit knobs and have them control different things  (a bit like Palette ($330 for a Travel Console)). This is what the Surface Dial can't do, as multiple devices would only map to the same Dial API.   The same goes for ordinary USB volume controllers, since all of them would map to the same volume +/- mute keys.

If you want to control different apps without having to reprogram, you can do so  with Autohotkey, which can remap the input keys  according to the foreground app.  This requires you to do some coding with Autohotkey though.

Granted, this setup UI is not the most user-friendly, but it gets the job done. If you prefer a more user-friendly setup procedure, you probably would prefer a TourBox   ($158) ​ or a designer keyboard ($90). Taobao users would have more options like this keyboard   (RMB 399 = $56) or this dial (RMB 138 = $20) that allow custom key assignments.   Iwit also offers a  larger video editing controller    (RMB 799 = $113) at Taobao featuring a knob, a shutter ring and a dial (see photo right), but again you have to deal with their special setup UI.

Personally I'm quite happy with using a keyboard with my non-dominate hand  for hotkeys.   In Expresii, we have made common tasks like undo and redo easier:  we have Z and X as hotkeys for them so that you only need to press one key, as opposed to Ctrl-Z or Ctrl-Y which requires some finger twisting.  We still support standard multi-key  commands like Ctrl-Z and Ctrl-Y for undo and redo so that, if you're new to Expresii, those familiar key commands you got used to are still there.

That said, the only missing piece from my standard keyboard is a dial. Or, a few dials. So, I put the two iwit dials besides my keyboard. Because they are wired and the connectors stick out, I can only put them side-by-side. One knob controls Brush Wetness (hotkeys Q W)  and the other Pigment Adjuster (hotkeys , .).   And I still have more assignments available for operations of knob short press, long press, and knob rotation while pressed. So, a total of 6 assignments    per controller.

In the future, we may add the support for using multiple mice on the same computer, so that you can use your spare mice's buttons and wheels for controlling different settings in Expresii. Leave us a comment to let us  know how you like this plan.

Microsoft added the ability to add custom tools for different apps for Surface Dial.  Here is a little walk-through of such a process.  To get to the right setting page, type 'Wheel' in the search bar and choose 'Wheel Settings'.  Then see the following screenshots for guidance:

This is also  useful if you have a device that mimics a Surface Dial , such as the   iwit knob we review here and the   Huion Q620M .   Hers is an example usage of the custom tool with Expresii:

The iwit USB volume controller is a great choice if you want to add a couple of dials to complement your keyboard. They are inexpensive but reasonably well made. We thought of using multiple mice for their  wheels, but this is not the same as a dial: you cannot keep rotating a mouse wheel like you can with circular motion for a dial.   When do you need such a motion? Rotating the paper like this.   ​(^.~)☆

There are tons of cheap Surface Pen alternatives out there available for purchase online. The cheapest usually marked as 1024 pressure-levels are around US$20. Newer models supporting tilt sensing are a bit pricier.

We acquired two Surface Pen alternatives from Taobao,  namely the IQS Surface Pen 4096  and the  WiWU   P503 'Picasso' Active Stylus for testing.  Both claim to support 4096 levels of pressure and tilt sensing. Tilt sensing seriously?! Normally a 2017 Surface Pen, which supports tilt, costs US$99, but these alternatives are only a fraction of this at around US$40. We bought them when there's discount so the final prices were around US$30 each.

If you can't use Taobao, there're online stores like Amazon that sell e.g. this VORCSBINE    (looks exactly like the WiWU reviewed),   this from Lengh (looks exactly like the IQS reviewed)   , this     Penoval,   or this NewPower,  which all at around US$40 and claim to support tilt. Those pens look very similar to those two we tested so we won't be surprised if they were actually the same pens just with different labels. We didn't found any review of these pens with tilt support so we will review a few for you.

The rubbery tip feels very good, just like using the original Surface Pen -  not making any scratchy sound or friction being too large impeding your flow nor too small that it feels like skating on ice. I actually like such a rubbery tip, typically found in the Surface Pen or its alternatives, over the tips provided by Wacom.   Recent default Wacom tips are quite easily worn out when stroking against their own drawing tablets like the Intuos Pro, while their felt tips are also easy to catch dirt (and get worn out too).

These Surface Pen alternatives don't have any Bluetooth module in them, so they can't perform top button shortcut clicks like the original Surface Pen. They also don't have magnets in them so you can't adhere them on the sides of the Surface devices,  at least not securely when it's only the battery  (enclosure made of metal) inside that provides a weak adhesion.

Testing shows these cheap pens perform quite well. The IQS seems to have a smaller activation force - I can press very lightly to get a very thin line with ease. The WiWU pen on the other hand needs more force to get registered and I do get some strokes not recognized or broken due to very light pressure being used. 

The 2017 'new' Surface Pen doesn't sense tilt when we use its Eraser end to stroke. These alternative pens don't have an eraser end - instead they have two barrel buttons, one being used as the Eraser button.  From our test, the WiWU doesn't sense tilt when the eraser button is pressed, while the IQS does sense tilt but with jitters when the eraser button is pressed. 

Like the 2017 Surface Pen, these pen sense tilt only when it touches the screen. BTW,  the pleasant surprise of Surface Go giving tilt reading even when hovering is gone after some Windows Update. :(

To our surprise, our Line Tests show the IQS pen is even more sensitive than  the original 2017 Surface Pen! See the following video for comparison:

Guys, I want to stress that it's not the pressure level,  but  the activation force  and the pressure response curve that matter here  - that which make you feel how sensitive the pens are. 1024 levels are actually very enough.   Due to the API used, the pressure reading is actually converted to 1024 internally if you use the 'Windows Ink' option in Expresii. If you are using Wacom,  by default Wacom's driver also converts the reading to 1024, no matter you're using a 4k or 8k-level pen (you can disable the 1024-level cap in Wacom's driver and see if you can tell the difference :-).  Truth be told, those 4k or 8k  numbers are purely for marketing purposes. However, you may ask, then why does the 2017 Surface Pen with 4k levels feel more responsive than its previous model with just 1024 levels.   The answer is that they also improved the   activation force  and maybe also the   pressure response curve .  With smaller   activation force ,  you don't have to push so hard for the stroke be get registered.  

Center of gravity also affects how the pens feel in your hand. Both the IQS and WiWU have full-metal bodies,  while the Surface Pen is metal except its top part being plastic.   The Surface Pen has its center of gravity right at it's middle along its length (shifting balance is probably one reason why its not all metal).  The IQS has its center of gravity  quite shifted towards its top part, making it feel a little unbalanced ​ when held in hand. The WiWU is only slightly shifted towards its top so it still feels fine. Our digital scale shows all  three pens weight roughly the same at 18-19g.

These cheap pens are really great alternatives to the original Surface Pen with excellent price-performance ratio.  In particular,  the IQS pen is great for artists because it can sense small pressure well, beating even the original 2017 Surface Pen. I'd say the IQS pen's pressure sensitivity is on  par with Wacom's.   The only thing missing is the ability to sense tilt even during hover like an EMR Wacom pen does.
​
For those wanting to buy Surface Pen now, note that the  next version of Surface Pen probably will have wireless charging. You might want to wait till Microsoft’s fall event on October 2nd.

We, of course, would still like to see digital writing hardware technology further advances - currently they are only mimicking pens with hard nibs. It'd be great if hardware makers can provide tools that  simulate brushes well.   Leave your comment on what else you would like to see in future digital writing instruments.

The recently released TabMate from Clip Studio  is a controller designed specifically for digital painting.  Long-time Expresii user Shuen Leung is very happy with the new controller. The following is a video walk-through for setting up the controller for use with Expresii:

The setup process is very similar to that of the Nintendo Joy-con. However, the TabMate gives constant left or up signals for the Left and Right Joysticks, so user would need to disable the Joystick readings or function assignment from inside Expresii.

Acknowledgement: we thanks Shuen Leung for lending us the controller and  providing feedback and suggestions using the TabMate. Let us know if you have any feedback in using similar controllers!  You can read more on the TabMate in this English review  by Scigor.

We recently added  native support for Microsoft Surface Dial.   The combination of   pen, touch and wheel gives you a new way to interact with Expresii.

Two custom menu items,   Rotate & Brush , are added specific for Expresii: 

When Expresii's main window is in focus, a press-and-hold on the Dial takes you to the above radial menu.  When Brush is selected, you can press the Dial to invoke our own Brush Control Menu, which has  four items, namely Brush Size, Loading, Wetness and Scratchiness:

For instance, you can use the Dial to adjust Brush Wetness while you stroke:

All of these controls, except brush size, can be adjusted as you stroke.  Yes,  as you stroke, instead of between strokes. Things  happen in real time.   You can rotate the paper with the Dial as you paint. By adjusting your pen tilt angle at the same time, thanks to the tilt-sensitivity of the pen, you can create  interesting patterns!    

When you enable gravity  in Expresii, your rotation actually  directs the ink flow. Expresii's advanced paint engine  give the most natural simulation of brush and ink hands down. You won't believe what your Surface device can do!

And of course the Dial is also handy for undo and redo. See it in action for yourself:

We had a lot of fun playing with   Expresii   &   the dial.   We hope you do too! ​As always, stay creative!    └(°ᴥ°)┘​

Soon after the Nintendo Switch was released in March 2017, digital artists have been using the controllers, called Joycons, as a hand-held controller for digital painting.  In contrast with all previous low-cost single-hand game controllers we tried before, the joycons ($80 a pair ) are equipped with gyroscopes, accelerometers and even IR motion camera.   ​

The joycons works on Windows even without installing a driver  but the analog thumb-stick only works as digital buttons.  Thanks to  this   Joycon driver for Windows   by Matthew Fosse, we can now also use the analog joystick (and maybe later the gyroscope too).

After installing vJoy and Joycon driver as instructed by the Joycon driver page, we are able to use Joycon for quick controls for Expresii. We had to connect the Left joycon instead of having left and right combined, since the mapping of the combined controls is different from what Expresii currently accepts. We tried  x360ce  to remap the controls but  we didn't figure out how yet. :)   Currently, Joycon driver outputs gyroscope data as rotational impulses rather than tilt angles so we can't really make use of the gyroscope  for brush tilt yet.   Anyway, here is a short video of using Joycon with Expresii:

We thank Mandy Ng of   Rooftop Animation    for providing the Joycons. ​

Previously we've been trying   cheap bluetooth VR controllers    but they either don't really support Windows, or they don't offer analog joystick input (joystick only act as buttons): 

Thanks to Shuen Leung, recently   we discovered a couple of Keysco   branded  bluetooth controllers that could act as analog joysticks under Windows.   However, they could only be seen as DirectX devices so we also added support for DirectX (DX) game controllers in Expresii. These should be the cheapest single-hand controllers that offer analog input for Windows on the market now.  And they are more comfortable to hold than then R1 shown in the youtube video shown above.  If you can communicate in Chinese,  you can get one from Taobao for RMB35 (=$5.3).   Otherwise, you can buy one from   Amazon    currently at $9.8 or   Ebay  at $6.95.

Below is a process walk-through video for connecting the controller and using it in Expresii.  You can press WIN and type 'joy.cpl'  and press enter to get to the control panel  item  for game controller shown in the video.   And FYI, those Keysco controllers we tested only give 4 buttons - those shoulder buttons actually maps to one of those A B C  D buttons!  Also, the analog sticks are not very sensitive as some of the more professional ones like XBox or Plasystation controllers.

Such a controller is useful for quick access  if you don't want to use a keyboard.   In particular, if your stylus doesn't sense tilt yet, you can also use the analog stick for pen tilt, or even for painting surface tilt.

Let us know if you need more function assignment  for game controller and we will consider adding them.   ^_^

The white one on the left doesn't even connect to a Windows machine via bluetooth,  although the description says it supports PC.   The Mocute on the  right connects to Windows device, but those buttons and  thumbsticks map to number keys - not working as a game controller as expected. :(

The Nintendo Joycon connects to a Windows machine via Bluetooth and can be used as a remote control for painting.   If you want a (much)  cheaper alternative,  here is one VR controller called 'R1' that costs only $5!  Thanks to  the booming VR  thing, there're many such controllers released recently, but you have to be careful because some of them do not connect to a PC.  The R1  in particular is known to connect to a Win8/Win10 PC via bluetooth. 

I love the R1 being a one-handed bluetooth device, but it may not be the most comfortable to use because of the positions of the buttons.  You can of course use a conventional game controller like we showed you in this blog entry, but then they are designed for two-hand operation and are less portable.  Personally, I use keyboard shortcuts mostly because when I paint, I'm mostly sitting on a desk.  I think if I train myself well, those controllers can be very useful for quick operations when I don't have a keyboard.  FYI, the R1 doesn't send multiple-button signal and the thumb-stick doesn't give analog signal when paired with a PC.  Normal game controllers  designed for the PC should have no problem with these two things.

We're also lucky enough to finally get hold of a Surface Dial.  The following  is a quick video  after we have had it for a few days with the Surface Pro 4:

My first impression for the Dial is that it's not designed for quick  muscle-memory operations. I wished it had more buttons.  As it is, I think it's best used for timeline scrolling or, like in our demo video, canvas rotation.  For zooming &  panning,  I surely prefer  multi-touch gesture.  Interestingly, a dial with buttons  actually  already exists - the  $60, wired  ShuttleXpress  (and also other similar products). Wish to try it one day.  ﾍ(=￣∇￣)ﾉ​

We cannot emphasize  enough  the importance of stylus tilt sensing.   If your graphics tablet  doesn't sense tilt, apart from using right-mouse-button-drag, you can still choose to add a game controller in the mix - a cheap one can be had for under US$10.  

In our demo, we use a PS3 controller, because it's also equipped with a tilt sensor that can be used for paper tilt in Expresii.

Since the P3 controller is not native to the Windows OS, we need some third-party software to make it work on the PC: MotionInJoy driver, Better DS3. You first install the MotionInJoy driver, which also comes with its own control mapping tool, but it's better to use the Better DS3 tool for easier mapping.

If your game controller is native to PC, you probably can simply plug and play.

To test the game controller we use Joystick Tester . We map the controller tilt to  R and U values as shown in the  Joystick Tester . 

The following is video showing how it works together:

The non-tilt-sensing graphics tablet used was a  Huion H420 (US$30). Its three buttons on the panel itself can be mapped to hotkeys  of your choice.  It's cheap  and good, except that  the battery compartment  gets rusty and gives bad contact  now. We have had it for one year only. Another downside is that the hover distance is very little compared to that of a Wacom.   But for $30, it's not bad an option for those who on a budget or want a very portable graphics tablet - it's probably the smallest graphics tablet that gives pressure reading!

And in case you also own a PS3 controller, here is the mapping we use.  You can first press the 'Auto Fill' button to get  a default mapping, and then modify it from there. It's  mainly the SixAxis Tilt that needs to be assigned as Right Stick (X, Y).