Home / BluArmor / Simple to Use, Powered by Tech: The Story of BLU3 E20’s User Interface


What is a good user interface, and how does one compare different user interfaces?

Is the iPod’s click wheel a better or poorer interface than the iPhone’s touch-screen? The easy answer is that the touch-screen is the better interface because no buttons are the same as infinite buttons! But is the answer that simple? What if you aren’t looking at your phone? Would you know what you are clicking on with a touch-screen? Now let’s look at the iPod’s click wheel – a simple interface where you know what each button does, and can locate the one you need. Imagine you are listening to music with the iPod in your pocket – want to skip a track, no problem. Just feel the transition from a surface to a matte finish, and you would have located the button you need to press. Quoting from The Verge, the iPod’s interface allowed you to add music to your life without demanding that you give your life back to the iPod.

We would summarize it this way: the right interface is one that understands the user’s state (context), his/her intended level of attention, and marries that effectively with the range of intended actions.

Our biggest stakeholder is the two-wheeler rider and it is an absolute necessity that his/her eyes stay focused on the road when s/he is riding. The rider is also probably wearing gloves and doesn’t have the luxury of navigating over the user-interface-area in search for the right button to press. With that in mind, we asked ourselves (and our rider community) the following question: Wouldn’t it be convenient for the rider if the entire user-interface-area was a single large button, a button large enough that we can call it a surface? The answer was an emphatic Yes!

That brought us to the next question: How do we achieve a number of different functions with a single, large, click-surface? Let’s think about a user-interface that we are all very familiar with – the mouse! The mouse allows us to initiate so many different actions through the variations in its “click” – single-click, double-click, click-and-hold, etc. It is simplicity at its best! BLU3 E20 takes inspiration from this simplicity and has a unique single, large, click-surface that supports all intended user actions such as music, phone calls, navigation, voice-assistance, location-aware voice-notes, responding to WhatsApp messages and pillion calls.

That’s the “what” part of it; let’s now take a look at the “how”

We started out by defining the possible clicks – single-click, double-click, triple-click and click-and-hold (long-click) – and laid out conditions for combinations of clicks. In cognizance of the rider’s state of mind and the need to maintain simplicity, the only combination we support today is the single-click followed by the click-and-hold (or) long-click. This left us with a very small number of possible actions that could be supported unless we allowed each click to have a different purpose depending on the rider’s context. A single-click could mean something when the rider is listening to music and something else when there is an incoming phone call. We have developed SAeFEx (Situation-aware Actions engineered For an Easy experience), a proprietary technology that is a game-changer when it comes to dramatically increasing the number of user intents while keeping the interface simple.

For SAeFEx to be effective, it is necessary for BLU3 E20 to stay in continuous sync with the rider’s smart-phone. The existing two-wheeler Bluetooth headsets do not support this because they employ the Bluetooth Classic (BT Classic) protocol – the ability of this protocol to handle data transfer is restricted to a few pre-determined commands. BLU3 E20’s unique TWOFLO technology simultaneously supports both BT Classic and BLE (Bluetooth Low Energy) protocols – continuous data sync can now be maintained between the phone and BLU3 E20 through the BLE link while music is being streamed through the BT Classic link.

There are a number of scenarios possible – the user could be activating intent through the click-surface, there could be an incoming phone call on his/her phone or the phone could be receiving an in-app or system notification. BLU3 E20/its companion app should be capable of understanding these different scenarios and ensure that there is no inconvenience for the rider while traversing these scenarios.

To address this effectively, we have used the type of rider activity and its associated priority to design a state-machine that can handle the states and state-transitions. Once we achieve the context (state) sync, it is easy for us to use the priority we assigned each state to handle the different interruptions/scenarios. The logic we follow is as follows:

  • Priority is constant
  • Direct state transitions can only be from lower to higher priority
  • State transitions from higher to lower priority will be through the idle state

A simplified version of the possible state transitions is captured in Figure 1.



Figure 1: State-machine and its transitions

A state transition can be initiated by the firmware on BLU3 E20, or by the companion app. The state transition event is accompanied by notification over the BLE link to ensure that the context is synchronized between BLU3 E20 and the smartphone.

The key advantage of this architecture is its scalability. We can easily add a number of new states to the system while retaining a simple user interface. Some of the possibilities we are likely to explore in the near future are

  • Custom user-programmable personalized actions via settings in the companion app
  •  New actions made available via software and OTA upgrades
  • Potential integration with the biking ecosystem to offer say, one-click access to road-side assistance

The possibilities are endless.

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