Turning an IKEA Frame Into a Smart Home Sensor

With a quick trip to the store or a web search, you can find a smart home sensor that will do just about whatever you want. However, not all of these sensors are as smart as we would like. They may do what they advertise, but if you have to change the batteries every few weeks, they are inevitably going to spend more time offline than doing anything useful. And aren’t you getting tired of the minimalist white plastic case that so many of these devices come in these days?

YouTuber Microamp Home has had it with commercial offerings for these reasons, but is not ready to give up the conveniences of a smart home system. So, to get everything he wants, he made his own smart home sensor. It was designed to run for at least a year on a single, tiny battery and it fits inside a picture frame so that it can do its job without cluttering up his home with ugly little plastic boxes.

The top priority for Microamp Home was to achieve extreme power efficiency. To get there, he tested multiple microcontrollers, including the ESP32-C6 and ESP32-H2, both popular in IoT projects. While these chips offered solid functionality, their sleep-mode power consumption — 121 microamps and 70 microamps respectively — fell short of expectations for a truly long-lasting device. The Seeed Studio XIAO nRF52840 proved to be the best option, bringing idle consumption down to just 9.15 microamps.

Paired with the microcontroller is a high-precision SHT41 temperature and humidity sensor, chosen not only for accuracy but also for its minimal power draw. Even when active, it consumes just around 1 microamp, aligning perfectly with the project’s low-energy goals. To monitor battery health, an Adafruit LC709203F fuel gauge was added, allowing the device to report its remaining charge directly to the user’s smart home ecosystem.

Using the Matter SDK, the device operates as an Intermittently Connected Device (ICD), meaning it remains asleep most of the time and only wakes periodically to send updates. Instead of reporting data every second, the sensor checks in every five minutes — a small compromise that yields massive energy savings. Network polling intervals were also tuned, though current smart home hub limitations prevented more aggressive optimization.

All components are hidden inside an IKEA photo frame, with a nearly invisible air channel carved into the plastic to allow environmental readings. Inside, modular I2C connections and compact wiring keep everything tidy and serviceable, while a somewhat modest 1,100 mAh lithium polymer battery powers the system.

With a total idle draw of just 18 microamps, the sensor achieves a theoretical battery life approaching seven years — far surpassing the original one-year goal. More importantly, it integrates seamlessly into modern smart home platforms. If you’d like to build your own smart home sensors, check out the video below for some helpful advice.