Tiles Update – we've added blinky blinky

Our project Tiles, little BLE-connected platforms for customer interaction tracking, is entering a project phase which allows me to blog and inform you a bit more. Since yesterday night, the Raspberry PI and Arduino in the hub uses one power source. This makes the overall design easier. We also have been working on a Raspberry PI B+ hat, using Eagle, to further optimize our design.

One visible change is also that it now blinks 🙂 The hub rotates an LED light to signal the BLE scanning process. It flashes once you liftup the product, well, the apple in this case.



We’ve now also locked down the architecture and below is a rough sketch that should help understand it. Again, a quick summary below.

tiles technical architecture

  • “Tiles” are the wirelessly connected platforms. We use Punchthrough’s LightBlue Bean and remove the battery holder to make the platforms 8mm high. We still use CR2032 batteries, which gives us about 1 week battery life right now. We would get more, but I send our a MetaEvent every 10sec which is hard on the battery.
  • The “Hub” collects all data. It scans for tiles, continuously, and connects. The hub runs on the raspberry pi, uses a BLE dongle (choice is key here) and uses node.js for all programming. It sends on data to the server with CoAP – a UDP-based IoT protocol.
  • The “Server” collects all data for all hubs (yep, there can be many) and provides the necessary APIs for managing the User/Tile association, authentication and authorization (Oauth2 used here), etc.

One more thing – I’ve connected the server to Xively, a data logging platform. We collect mainly the battery rundown to estimate battery life and also the temperature values from the lightblue beans. At this point I just want to share some nice graphs to show you how much sense it makes to track that data. It will definitely help us to optimize the design / battery consumption further. Right now we stay optimized for demo purposes, but we can later reduce the events sent for example to get a better battery life.

Screen Shot 2014-11-27 at 9.49.19 AM

Screen Shot 2014-11-27 at 9.49.13 AM



Tell us what you think:

3 thoughts on “Tiles Update – we've added blinky blinky

  1. Georg Kreimer says:

    Hey Sven,

    Very cool to see the progress. Any plans on adding any type of feedback to the tile for the user or is your plan to purely capture user interaction and meta data? (The tiny battery probably limits it to just doing that)


  2. Sven Haiges says:

    Well, there is feedback. The hub has a neopixel ring that “scans” – e.g. rotates a pixel around the circular shape. When you lift a product, it flashes that ring. The tiles themselves do not show any feedback – I am really trying to save power here.

    It is btw really hard to find good CR2032 batteries. They should have a charge higher than 3V when they are fresh – but most are below. I am still getting around 4 days continuous runtime. If I would drop the connection (e.g. in a store at night) I would alrady double that time. Then, if I drop the MetaEvents that aggressively send out battery and temp data every 10 seconds, I am sure we can again increase the live time.

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