Bluetooth Smart temperature sensor enables a smartphone to monitor temperature
Nordic Semiconductor ASA has announced that British startup, Blue Maestro, has specified a Nordic nRF51822 System-on-Chip (SoC) in each of its GBP £29 ($50) ‘Tempo’ Bluetooth Smart (Bluetooth low energy) temperature sensors that allow consumers to accurately measure and monitor air or water temperature 24×7 anywhere in their home or business, from a smartphone.
In operation, the weather- and water-proof Tempo is takes full advantage of the embedded Nordic nRF51822 SoC high +4 dB maximum output power to maximize operating range to up to 250-ft (75m) -— including through walls and floors (which will, however, reduce the range depending on construction material) — while still achieving a one-year continuous use operating life from a pair of regular (and user- replaceable) AA batteries due to the class-leading ultra low power operating characteristics of the nRF51822.
Each Tempo advertises the current temperature once every two seconds and records temperature in its memory once an hour over the previous 24 hours so users not-in-range can track the temperature behavior when they are next in range through a free Android or iOS app. The app will provide alerts at pre-set temperature thresholds, even when running in the background. And Blue Maestro claims there is no (for practical purposes) upper limit to the number of Tempos that can be operated simultaneously and that the product requires no set-up beyond downloading the app.
Temperature is measured using a high accuracy thermistor that monitors air or water temperature (rather than less accurate casing temperature) in the immediate vicinity of the Tempo to allow even subtle variations to within ±0.2 °C to be immediately detected. Readings can also be ‘read’ out loud for the visually-impaired.
"In terms of the design and technology that has gone into it, it is a little excessive for just temperature," admits Blue Maestro Chief Executive and Co-Founder, Richard Hancock. "However we have a development schedule that will see its capabilities quickly expanded to include humidity and barometric pressure, increased data storage, and we are developing a Wi-Fi hub that will allow users to monitor their Tempos remotely over the internet. We also plan to enable Tempos to talk to other Bluetooth Smart devices so that certain desired events can be automatically triggered, such AS turning the heating on, off, up, or down."
Hancock says even in the Tempo’s current form its application range is extremely appealing to a wide range of end users. New parents, for example, can use a Tempo to remotely monitor the temperature of their baby’s room. And pet owners can monitor the temperature of pet enclosures and aquariums (reptiles in particular can be affected by even a relatively small drop in environmental temperature). Gardeners can monitor their plants and vegetables in green-houses, and professional staff can monitor room temperature in care homes, serviced apartments, and hotels.
Hancock continues: "We believe devices such as these also have a part to play in improving energy efficiency since users are able to accurately monitor both macro (large, room-scale) and micro (localized) temperature variations that allow far better adjustments to be made to thermostat and radiator settings."