After having teased the device for a very long time, in the end, TG0 has launched its innovative Etee controllers on Kickstarter. There have been many online debates on these devices, with some people telling that they are the future, others telling that they have an awful design.

I got an exclusive devkit before the lockdown, so let me tell you my impressions on them so that you can understand who of the above groups of people is correct.

What are the Etee controllers?

Before going on with the review, let me explain you what are the Etee controllers. These are a pair of hand controllers designed by startup TG0, with the idea of creating a new kind of controllers that are more natural to be used than the standard VR ones.

TG0 thinks that current controllers like Valve Knuckles or Oculus Touch are nice if you are already a gamer, but they can become complicated for people that don’t come from a technical background, and that aren’t used to the standard abstractions provided by joysticks. So the engineers at the company started thinking about controllers that could be:

• Ergonomic
• Easy to be worn
• Natural to be used, without buttons and other abstract concepts
• Easy to be cleaned

The result of all this work has been the creation of the Etee controllers, that look like some knuckles that you put around your fingers to detect the movements of your hands. These controllers are 3DOF, but TG0 is also offering a 6DOF version using SteamVR tracking (now, in the devkit, you have to pair them with Vive Trackers to use them in 6DOF inside VR, but the final product will come with 6DOF out of the box).

Let me show you how they work!

Etee controllers unboxing

It wouldn’t be a Skarredghost’s review without an unboxing video! So, here you are me unboxing the controllers at home on a nice table full of smiling bees 🙂

The shipping box contains the controllers, a Bluetooth dongle and two cables, and I have to praise the very elegant design of the top of the box. But what surprised me when I opened the box is the very pleasant smell of the controllers… it seemed like flowers scent to me. Jakub from TG0 told me that it is the silicon material that smells very well. It is the first time that I have an olfactory experience during an unboxing, this was very interesting.

Setup

When I downloaded the software package related to Etee, I found a practical guide on how to use the devices.

The setup process is super-simple:

• You put the controllers in charge using the USB-micro cables provided in the box. When the light of the controllers go from orange light to off, they are charged;
• You attach the Bluetooth dongle to one of your USB port;
• You turn on the controllers;
• You wear the controllers;
• You’re ready to go!

Basically, I made a five-points list just to tell you that basically they are “plug and play”… but you know, we engineers love bullet lists 🙂

The setup is exactly easy and user friendly as the company imagined.

There are two extra setup steps that may be necessary. One is the firmware update, and the other one is the calibration.

Firmware update

To update Etee’s firmware, you have to use the firmware update tool provided with the runtime. You have to connect one controller at a time to the USB port of your PC with the USB cable provided and use the window of the tool to update the firmware using a firmware file you have downloaded online. You can also update the firmware of the dongle.

The firmware tool is a bit rough, and I see a lot of room for improvement, but it gets the job done. You can also use the same tool to do other things, like configuring the device to be used as a mouse, for instance.

Calibration

Like the Valve Knuckles, the Etee controllers must be calibrated for optimal use with your particular hands. So, after you have worn them for the first time, you must open the Visualizer tool, and

• Reset the sensors pressing the R key on your keyboard, and then keeping the hands still, parallel to the floor for some seconds;
• Trigger the calibration pressing the C key, and opening and closing your hands once.

You can use the devices even without these operations, but from my experience, the accuracy would be very mediocre, so I don’t advice that at all.

Anyway, doing this is incredibly simple as well. The setup procedure is approved.

Etee video review

I’ve prepared a video that summarizes my impressions on the Etee controllers and also shows them in action! If you like videos, here you are:

Otherwise, keep reading for the textual explanation.

Design

The Etee controllers are two tubes covered in silicone (they remind me of Italian pasta called Penne Rigate) with a plastic handle attached to them. On the front of the device, there is a big light, that changes color depending on the status of the controller (e.g. Green = tracking, Orange = squeezing, etc…). On the bottom, there is the switch to turn them on and off. That’s it. The spirit of TG0 is having a very simple controller, that’s why there are no buttons or anything else.

I think the design is very original if compared to the other controllers, and it is also elegant to be a devkit. Maybe what it can improved is that the controller looks a bit “sad” with this opaque black rubber all over it. Probably I would look at a more colorful design (but I’ve read on the Kickstarter page they’re working on it).

Ergonomics

You wear the controller by putting your hand inside the handle, making the cylinder rest at the base of your fingers, where your palm begins. The fingers from the index to the pinky can so bend around the cylinder, while the thumb resting on the top touchpad. Since the handle is covered in sponge, it exerts pressure on the back of your fingers and the controller remains attached to your hand even if you open it, a bit like the Valve Knuckles. This means that you can open and close your hands as you wish.

I think that ergonomics are one of the two Achille’s heel of this solution, something that should be improved from the devkit to the production stage. I don’t mean it’s bad, but it should be better.

On the good side, the controller is super-light, and doesn’t detach from the hands, even if you move them fast.

On the bad side, the fact that the cylinder doesn’t stay fixed in the palm (like with the Valve Knuckles), but it is attached to the first phalanx of the fingers, makes it feel less natural. Fingers are very sensitive, and since you have this thing continuously touching them on the front, and the sponge of the handle applying pressure on the back, you have a continuous reminder that you have something attached to your hand. This feeling is amplified by the fact that the cylinder moves while you bend your fingers, and so it continuously changes the parts of the skin it touches, also preventing the habituation of the skin to the sensation of touch with the device (as it happens with Knuckles, for instance).

Furthermore, since the handle clinches the fingers, it also prevents them to spread (e.g. to make a hello gesture). And since it is shorter than the dimension of my hands, the ring and pinky fingers feel looser than the index and middle ones.

TG0 claims that the thumb is in a comfortable rest position by being on the top touchpad, but this is true only up to a point. While I haven’t found the position of the thumb uncomfortable (it is far better than the one requested by the Index Controllers), it is not completely natural either.

The comfort of the overall device is mediocre and could be improved a lot by moving the sensing cylinder on the palm, and by providing different handle sizes for different hand sizes, because the default one is for instance too little for me. I think it’s too late to change the design of the former, but maybe we can hope for the latter for the shipping of the device.

Features

The whole Etee cylinder is full of sensor that can detect when a finger is touching it or squeezing it.

So, the Etee can:

• Detect the bending degree of a finger, for all fingers from index to pinky;
• Detect if the finger is squeezing the controller, for all fingers from index to pinky;
• Detect the position of the thumb on the top touchpad;
• Detect if the thumb is pressing the touchpad;
• Rumble if any of your fingers is pressing the device: the more you squeeze the controller, the stronger it rumbles;
• Detect the orientation of the whole device;
• Detect the acceleration of the device on the three axes.

Starting from these data, the runtime can also extract some higher level information, like for instance some gestures: it detects if you are pointing at something (only the index finger is open), if you are pinching (thumb and index fingers are squeezing), etc…

You may ask me how well all of this works, and my answer is actually pretty well. Provided that you perform a good calibration, the device detects with good accuracy what fingers you are pressing, and if you are squeezing it.

TG0 claims that you can use the various fingers squeezing the controller in place of button triggers, and from my tests, it is reliable enough that it should work. The only issue is that sometimes the device is a bit too sensible, and detects a squeeze when I’m just touching the device. Also, the continous rumbling given from the squeezing (that is automatic), is pretty annoying on the long run.

But from what I can say, it delivers what it promises, and future software updates can continue improving the accuracy over time.

Use without VR

The controllers as-is are 3DOF ones, and so they aren’t very useful for virtual reality.

Etee provides with the runtime just a 2D visualizer, and then the setup software with which you are able to transform the input from the Etee to input from the mouse, gamepad or keyboard. This means, for instance, that you can use your thumb on the touchpad of the controller to move the mouse cursor on your PC, and the squeezing of your Index to perform the left click.

While I find this application interesting, I also think that is a bit gimmicky. For instance, after having tried the Tap-With-Us keyboard, I can tell you that it’s very difficult to substitute a keyboard with a more abstract design where you have to remember some gestures.

I think more interesting uses will come from developers/makers using the SDK to create some 2D apps.

Use with virtual reality

If you buy the 6 DOF Set, you can use your Etee controllers with SteamVR games. TG0 already provides the input mapping so that you can emulate the input of the Vive Wand with your Etee controller: for instance, the thumb touchpad is equivalent to the Vive Touchpad, and the Index squeezing the controller simulates the Vive trigger.

Thanks to this emulation, you can use Etee controllers with all SteamVR games, and TG0 has already showcased it with SuperHot, Half-Life: Alyx and other games. The controllers have also been implemented inside the social world NeosVR.

Regarding usage in VR, I think that Etee have potential, as all the controllers enabling full finger tracking in VR. Using the whole hands in a natural way, employing all the fingers is always a good thing. But… I have two big BUTs:

1. Etee tries to mix the best of fingers tracking solutions like Leap Motion with the best of controllers like Oculus Touch. With it, you have both full fingers tracking and haptics feedback. But on the other side, it also adds the drawback of both solutions, for instance not giving you proper binary input (buttons), that make you understand immediately that you have performed an action. With the non-binary input of the “squeezing” action, doing an input like shooting with a gun becomes more uncertain;
2. No game has been made with the Etee controllers in mind, while all games have been made thinking about a design compatible with Oculus Touch-like controllers. Playing in VR using Etee will never be perfect: many existing games won’t feel natural when played with a device they haven’t been thought for. It’s a bit like when I played Half-Life: Alyx with the Vive Focus Plus… input was a bit strange, because Valve hadn’t tested the game with that device.

For the above reasons, I think that Etee controllers would be ideal with an application designed to have them as input, and not an already existing experience. I see its potential for using it in applications in the field of training and fitness in VR, for instance, more than using them to play a game on SteamVR.

SDK

I have had a tour of the Unity SDK for Etee controllers, and I think that it gets the job done. You have a prefab that lets you access all the data of the controllers, from the orientation to all the statuses of the fingers, not to mention the detected gestures. Using these data, you can create the application that you want.

There is also already support for using the controllers in a VR application using the standard SteamVR plugin.

Probably what it lacks is a prefab already matching the data from the sensors to a 3D hand pose if you don’t want to use SteamVR tracking.

Battery time

Etee’s battery lasts up to 6 hours continuous use (14 hours standby). That’s enough for most uses. To charge the controllers, you can use the USB-micro cable provided in the box.

Price and availability

The device will come in the following tiers:

• 1 3DOF hand controller: around 147€
• 2 3DOF hands controllers: around 227€
• 2 6DOF hands controller: around 296€

Price is comparable to the one of Valve Knuckles, if you look attentively.

ETA is the end of the year: at the beginning was around October, but now many deadlines have been postponed to December due to the coronavirus impacting the supply chain. As with all Kickstarter campaigns, further delays are possible, but TG0 has the goal of shipping all the controllers before Christmas.

Final impressions

It’s hard for me to express a single final opinion on the Etee controllers.

On one side, they exactly deliver what they promise: the controllers are easy to be used, are very light, and they track the fingers quite well. Yes, there are some detection errors here and there, but most of the time, it works great. The device can work with and without VR, it is compatible with existing games and there is a Unity SDK that lets you create with it what you wish. It seems to check all the boxes.

But on the other side, apart from the problems with ergonomics, it remembers to me the old-school Leap Motion, in the sense that is a solution looking for a problem. The use with existing games is suboptimal, because they have been designed for controllers having buttons, and so it is not clear the value of spending around 300€ to have something that is not 100% compatible with your content.

I see instead its value for custom content. Some training applications may benefit from it: for instance, the controllers look like the cloche of a helicopter, and so may be good for a training experience in that environment; they detect finger movements, so they could be used for rehabilitation of hands for patients having lost mobility in the arms; they could be used for fitness games: they look like Knuckles, so they can be cool for a boxing game (HitMotion: Reloaded anyone?); they can create a WOW effect for the visitors of some booths in exhibitions. I think that makers may love it, and so R&D centers, universities, and so on. They are to me a device for enterprise/prosumer usage, more than a consumer one.

So, if you’re the kind of people that love to experiment with Virtual Reality, or you have an experience in mind where you need full fingers tracking, head to Kickstarter and support the Etee controllers! The more variety we have in the VR ecosystem, the better. Good luck to TG0 for its crowdfunding and the launch of Etee!

And as always, if you have any questions related to these devices, or any opinions to share, feel free to add them in the comments section!

(Header image by TG0)