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Portable external display, continually updated with data from a cloud backend.

Project overview

  • Development of a portable external display.

  • Part of Energomonitor, an IoT system for online monitoring of utility consumption.

  • 1 year from conception to shipment — fall 2016 to fall 2017.

  • Development started from scratch. Everything was built from the ground up.


Why a portable display?

Energomonitor’s user engagement tended to rapidly decline in the period after about 2–3 months. After the initial excitement of seeing utility consumption in real-time, users logged in to the Energomonitor app less and less. This was a fundamental problem — how could we maintain user engagement? We had to make the data easier to access by keeping it always in sight, not only in the app. Thus, an idea of a portable display showing the data was born.

Key decisions

  • The device had to be highly portable. Users must be able to take the screen with them from room to room, across the house.

  • Content must be easily readable and comprehensive. The device is intended for quick checks, not for targeted research.

  • The device should be constantly connected and be able to show all kinds of values, including aggregations, minimums and maximums, conversions for money amounts, or data from any Energomonitor installation, not only a local one. This would be our killer feature compared to the competition from similar devices other than Energomonitor.

  • The device must be elegant and aesthetically pleasing to an observer because it is something you are supposed to look at every day.

Key development steps

Hardware design
  • The device is powered by batteries. This was a result of the portability decision.

  • The screen is a classic segmented LCD. This was a reasonable compromise between battery lifetime, readability, and ability to show the necessary content. We only had to deal with limited number of the segments and restraints regarding the space and distance between the single segments.

  • The chassis is made of anodised aluminium, which is elegant and feels nice to touch.

  • To make device placement as easy as possible, there are magnets in the back of the device and a simple stand. The user can place the display on any table or shelf with the help of the stand, or to attach it to any metal surface, like a fridge.

  • The device has built-in temperature and humidity probes.

Conceptual and content design
  • After about ten iterations of screen design, the display shows two values from the Energomonitor installation. Based on our research we decided that two precisely chosen and clearly visible values were better than fifteen small ones.

  • The device clearly shows data and values, and works just as a displaying unit. There are no controlling or operating elements, like menus or hardware buttons. All the configuration is done in the application.

Software implementation
  • Shown content is configurable, operated, and sent from our servers. The device itself does not have any internal computation.

  • A content of the display device is “commanded” by an internal service called Commander, used for bidirectional communication from server to hardware.

  • In the online web app there are options which allow the user to configure what values his display shows. He can choose from whatever data he has access to inside his user account.


Right now Portasight is being sold as the part of Energomonitor system.

  • Combined hardware/software product which shows data from any Energomonitor installation, with values updated every 5 seconds.

  • Long life, with 2 AA batteries at least 1 year.

  • Shows two user selected values on a low power LCD.

  • Contains sensors of its own, an internal thermometer and humidity meter.

  • Designed with an anodised aluminium chassis and wooden back. Only 14 mm thick.

  • Can be placed almost anywhere: with a practical stand for desks or counters or via magnets in the device to any steel surface.

  • Totally wireless device, 100% portable.

Selection from the development history

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