History and Story of SUNREG

The first control unit saw the light of day in November 2023. An online store was created, and programming of the basic functions began. Development continued until August, when test operation started on an outdoor pool along with fine-tuning of the control software. Even though the device worked fully automatically—turning on in the morning and starting to heat the water—we realized it was inconvenient to check the temperature, as it required walking to the unit and reading it on the display.

And even though the first orders from enthusiastic customers had already started coming in, I decided to pause development and production until the unit could connect to the internet and allow temperature monitoring via mobile phone. We wanted a perfect device.
The first experiments began to connect a Wi-Fi module to the existing unit. Despite all efforts, after 14 days of testing and searching for the best solution, we still couldn’t make it work properly.
The decision was made! We had to switch to a completely different chip that already had built-in Wi-Fi communication. However, that meant starting over from scratch—testing and debugging new hardware. The biggest challenge turned out to be the analog-to-digital converters, as we couldn’t get satisfactory and accurate results from the temperature sensors. After several days of experimenting, the problem was solved with an external A/D converter with four I2C inputs, which provided incredibly stable temperature readings.
The hardware design was fully tested within a few days, and test prototype boards were ordered. Thanks to the new design, we managed to reduce power consumption and miniaturize the components.

And then came programming again. The original SUNREG-23 was a walk in the park compared to the new version, which required not only re-implementing the original logic but also adding Wi-Fi connectivity, OTA firmware updates, and MQTT communication. On top of that came setting up the MQTT broker server, adding security certificates to prevent hacking, and developing a mobile app. In total, about three-quarters of the system was completely new.

First prototype of the SUNREG-23 control unit
Test setup and hardware verification
Another prototype of the SUNREG-23 unit
First prototype of SUNREG-Wi
Second prototype of SUNREG-Wi
Final version of SUNREG-Wi