Dots – indoor service discovery using ultrasonics.

Pushing forwards the frontiers of service discovery ultrasonically

Dot with attached Particle and AAA battery

These were developed for a proof of concept research project. Slap one of these onto every printer, fax, PDA and gadget. Then slip a Relate dongle into your laptop. As you walk around your building your software will automatically detect and locate each of the devices. The fancy schmancy interface allows you to locate the devices and share services – drag and drop documents for instance. The Relate project hyperbole for the Dots states something like ‘Small ultrasonic transducers that allow the automatic recognition and location of distributed services.’ I was tasked to design and implement the hardware and no-one is more surprised than me that it all actually worked! The initial prototypes were two layer, the final item slimmed down to a four layer board. The RF communication was done via Techo Particle boards – these had been selected for all RF communication for the Relate project before my arrival.  I made the outline of the four layer Dots fit the footprint of a Particle. See below for a .jpg of the Dot schematic. The schematics and layouts were all done using the Eagle software package, available for free from

The schematic and board layout files for the four layer version can be downloaded from github.

Dot schematic.

Dots, top and bottom.