NORDIC Semiconductor’s Systems-on-Chips (SoC) will be used by Estimote in its Sticker beacons that make everyday objects “smart” and trackable.
Estimote Stickers are small and low-cost beacons that have built-in accelerometers and temperature sensors. They are designed to be stuck on everyday objects, allowing the objects to provide contextual and microlocation data to devices nearby using Bluetooth Smart.
The Estimote Stickers will utilise Nordic Semiconductor’s nRF51822 SoCs to provide the Bluetooth Smart wireless connectivity.
According to the developers, the Stickers herald a new paradigm of “nearables” which will enable new types of context-aware apps and help drive growth in the Internet of Things. By allowing smart phones and other portable devices to recognise their immediate surroundings and nearby objects, a new class of virtual applications can be built on top of the physical world.
Estimote did all the design work in-house in partnership with Nordic Semiconductor to achieve the required sticker-sized level of integration without sacrificing operational reliability or battery life – the Sticker is expected to have enough power for one year under typical usage conditions.
The designers were challenged by the thin form factor of the sticker beacons, which measure around 3mm thin. They had to find a balance between the flexibility needed for the sticker to work practically, and stiffness, needed to keep the PCB and components intact during regular use.
The problem was compounded by the 10 different shapes of beacons, which provided an extra dimension of personalisation. This meant a number of iterations were required to optimise the PCB layout. Estimote tested dozens of different silicon types and moulds to find the perfect fit.
The Nordic nRF51822 SoC’s 32-bit ARM Cortex M0 microprocessor and 256 kB of Flash memory on-board enabled Estimote and its customers flexibility in terms of applications – an important consideration since some larger customers require custom applications.
Nordic provided a reference antenna design which proved a good starting point for Estimote to focus on testing and optimising different configurations in a constrained space. The developers also took advantage of Nordic's rich SDK by using it side-by-side with Estimote’s own custom low-level code in interacting directly with the radio, helping further minimise the energy consumption.