The art of minimizing power consumption

BeAware has created a sensor solution for real-time measurement of indoor air quality. EKTOS has helped BeAware translate their unique product idea into a technically sound solution.

Ensuring the battery capacity for the battery powered version of the device as well as a cost effective production design have been two key focus areas for the engineering team at EKTOS.

With a team of engineers in Ukraine, two accredited test laboratories in Denmark, and production facilities in Ukraine EKTOS has the perfect setup for handling the entire process from designing the printed circuit board though international regulatory approval to mass production.

Managing the sensors

Besides the RHT, CO2, sound level, PIR, and light sensors, as an IoT device that sends data to an app, BeAware’s solution contains an RF module. When a battery is meant to keep the modules powered for years, the calculations for the power budget become complex.

In order to ensure minimal power consumption, the design of the power domains was carefully calculated, tested, and fine tuned at every stage of the development process from early bread-boards to the final prototype.

The cost of communication

Sigfox was chosen as the network technology to minimize the power consumption of the RF module while ensuring optimal coverage. Sigfox operates with very small data packages pushed to the cloud. When selecting the proper radio technology the trick was to strike a balance between the amount of data pushed to the cloud, the link budget, and the output power of the Sigfox transceiver. Selecting the right antenna and precisely matching it was a central part of the process.

IoT Denmark, the Sigfox operator in Denmark, has been helpful throughout the design process by giving access to the Sigfox back-end and consulting on the different subscription options. This has allowed the engineers to design the software to match the optimal subscription model.

E-ink as a power-efficient display

E-ink only consumes power when the display changes, like when a page is turned on an e-book. This is why e-ink is a power efficient solution for the BeAware device where the data on the display is updated every 10-15 second or less, if the PIR does not detect movement in the room. Despite the low power consumption the e-ink technology offers high contrast and ensures high readability even on a distance.

From prototyping to large scale production

During the design phase of the electronics circuits EKTOS’ engineers chose to only use easily available modules and components that could be mounted purely by machines. DFM, Design for Manufacturing, minimizes the production cost and complexity and ensures that the product is optimized for the production processes, in this case at TECHTO Electronics.

Similarly, during the design phase, frequent measurements of the radio performance and electromagnetic compatibility performance were carried out. IoT devices are covered by the Radio Equipment Directive (RED, former R&TTE) which stipulates a list of requirements to radio-enabled devices when they are to receive the CE-mark and be sold in the EU. At EKTOS we operate two test laboratories and are therefore very familiar with the requirements for CE-marking. We make sure to incorporate them early on in the design phase.