Case study: Development of IoT smart sauna system

Project overview:

The client, Sauna manufacturer from Finland, needed a completely new product, that will enable monitoring and control of sauna via cloud.
Intended use of this system is for predictive maintenance, better insight into sauna usage, remote control and remote technical support.

The approach:

After analysis of project requirements, we have build a quick Proof of Concept (PoC) demo to verify customer’s requirements.
Considering the results from PoC tests in real working environment, we proposed the following architecture for the final system:

The system includes 4 boards:
– Wi-Fi gateway
– sensor board
– Main control board
– high current heater control board.

Main control board is reading data from sensor board, forwarding information to gateway board which connects to AWS cloud service.
Information about heaters and current consumption is collected from “high current board” and forwarded to the AWS cloud.
Firmware supports over-the-air updates, sauna scheduling, stove fan control and monitoring.

Sensor board includes:
– Air quality sensor
– Humidity and temperature sensor
– Infrared temperature sensor
– Acoustics (noise) sensor

Control board contains isolated inputs and heater control outputs, but also circuitry for monitoring heater current consumption via isolation transformers and current measurement chip.

Our team did the following:
– Hardware design
– Firmware development
– Development of PC software for device configuration
– Integration of device with AWS cloud service
– Development of software for creating and flashing unique AWS certificates
– Manufacturing support