Sentinum launches Juno cellular tracker for asset location and monitoring
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IoT solutions company, Sentinum, has released a cellular IoT-powered asset tracking and condition monitoring solution built on Nordic Semiconductor’s nRF9151 low power SiP module and nRF7000 Wi-Fi 6 Companion IC. The ‘Juno Cellular Tracker’ is designed to provide continuous insights on the location, handling events and operational status of mobile or distributed assets.
Juno integrates a three-axis MEMS accelerometer to provide three key sensing functions—motion, tilt and detection of opening or tampering—that support activity-based tracking, misuse detection and automated event logging without the need for additional components. ‘TH’ model versions of the Juno solution also include a high-accuracy temperature and humidity sensor to deliver accurate readings of surrounding conditions for environmental monitoring. The sensors are supervised by the integrated Nordic nRF9151 module’s 64 MHz Arm Cortex-M33 dedicated application processor, including 1 MB Flash and 256 KB RAM.
nRF9151 cell-based locationing
To complement its condition sensors, Juno employs hybrid positioning technologies optimised for indoor and outdoor environments. SSID-based Wi-Fi scanning is used to capture nearby MAC (media access control) addresses and resolve position with 2–50 m accuracy, ideal for indoor or dense urban areas. GNSS provides precise outdoor positioning and is used selectively to minimise energy consumption.
When Wi-Fi and GNSS are unavailable or when ultra-low-power operation is required, cell-based locationing is used to estimate position. Using the nRF9151’s multimode LTE-M/NB-IoT modem and GNSS, the Juno device can operate on cellular networks for reliable, wide-area data transmission without requiring local gateways or additional infrastructure. The Juno Tracker’s intelligent firmware automatically selects the most efficient locationing method, switching between Wi-Fi or network-based indoor positioning and GNSS outdoors.
Nordic’s nRF Cloud powered by Memfault plays a central role in the Juno system architecture by providing a secure, scalable and standardised backend for device management and geolocation processing. By using Nordic’s infrastructure, Sentinum can offload complex operations from the device, reduce power consumption and streamline fleet management for its customers.
For positioning, Juno devices transmit GNSS and Wi-Fi scan data directly to nRF Cloud, where the final location is resolved using Nordic’s global databases. This cloud-based approach eliminates the need for power-intensive processing on the device and ensures high accuracy even in challenging environments.
“When designing the Juno Tracker, our priority was to build a compact, low-power device capable of running advanced tracking and sensor logic autonomously over long periods without maintenance,” explains Manuel Hart, the co-founder and general director of Sentinum GmbH.
“The Nordic nRF9151 was the only cellular SiP module that could meet all these requirements in one platform. Its powerful processor and generous memory give us enough headroom to run our hybrid positioning algorithms, event detection logic and firmware over-the-air update [FOTA] functionality directly on the device – without needing an external MCU.”
Power-efficient location updates with Wi-Fi scanning
In addition to the nRF9151, the Juno Tracker employs the Nordic nRF7000 Wi-Fi Companion IC. With a primary focus on active and passive scanning of Wi-Fi access points, the nRF7000 offers a reliable and power-efficient solution in location-based applications. It is designed specifically for SSID-based Wi-Fi locationing across both 2.4 GHz and 5 GHz bands, which gives the Juno Tracker the ability to locate itself even inside buildings or dense urban areas.
“We chose to integreate the nRF7000 Wi-Fi Companion IC because it solved one of the main limitations of GNSS-only tracking — maintaining accurate positioning in indoor or signal-obstructed environments without draining the battery,” says Hart. “By adding Wi-Fi scanning through the nRF7000, we can offer faster, more consistent and more power-efficient location updates, which directly translates into longer battery life and more reliable tracking data for our users.”
With optimised settings—such as one daily uplink and one daily GNSS fix—the tracker can operate for multiple years, even under challenging conditions like weak cellular coverage or limited satellite visibility. In higher-activity modes, users can still expect long-lasting performance without the need for recharging, according to the company.
“A key reason we selected the nRF9151 SiP was its exceptionally low-power architecture. The integrated MCU and modem allow us to precisely control every subsystem’s sleep and wake cycles, ensuring the device remains idle most of the time and only activates when events or scheduled reports require it,” says Hart.
The Juno Tracker is fully integrated into Sentinum’s sensor-to-cloud ecosystem, which includes the company’s dedicated tracking platform, ‘Orbix’. Data is processed and visualised through the ‘Sentinum Dashboard’ (built on the enhanced ‘ThingsBoard’ platform) or can be integrated directly into any third-party platform or customer-preferred software via standard APIs. This ensures reliable, scalable asset visibility within existing operational systems.
“Overall, we chose Nordic Semiconductor not only for its low-power cellular technology but also for the strength of its development ecosystem,” says Hart. “The nRF91 Series gave us the energy efficiency we needed for multi-year battery life, and the nRF Connect SDK (Sapphire) made firmware integration and FOTA updates straightforward.”
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