Azume One crowdfunding adds health tracking to analog watches via 2.8mm Bluetooth sensor

Azume, a Munich-based startup, has launched a Kickstarter campaign for the Azume One, a compact health tracker designed to retrofit analog and traditional wristwatches with smart health monitoring capabilities. The 30mm diameter, 2.8mm thick module weighs 5 grams and uses a nano-suction mounting surface to attach to watch casebacks without adhesive or magnets, allowing users to transfer it between compatible timepieces. The device incorporates an optical PPG sensor for heart rate and blood oxygen measurement, a motion sensor for activity tracking, and skin temperature monitoring, transmitting data via Bluetooth 5.4 to companion Android and iOS applications.

The Azume One offers up to 48 hours of battery life with approximately 30 minutes of charging time via an included USB-C charging station. For sleep tracking or workouts without a watch, the module can be inserted into an included FitBand wristband. The company claims automatic detection of over 28 workout types and provides Recovery, Sleep, and Stress scores through an app that establishes a user baseline over two weeks. Data is stored on servers in Ireland with GDPR compliance, encryption in transit and at rest, and optional Apple Health integration. The project is currently undergoing CE and FCC certification with estimated delivery in December 2026.

Hardware architecture and sensor design

• MCU speculation: The main processor is not officially specified, though the article notes it is potentially Nordic Semiconductor nRF52-series based, a common choice for low-power Bluetooth 5.x wearable designs.
• Sensor suite: The module combines an optical photoplethysmography (PPG) sensor for heart rate and blood oxygen (SpO2), a separate motion sensor for activity and workout classification, and skin temperature monitoring for recovery and stress metrics.
• Mounting mechanism: A nano-suction surface using microscopic suction cells enables residue-free attachment to flat watch casebacks, with an alternative FitBand nylon wristband provided for use without a watch.
• Connectivity and power: Bluetooth 5.4 handles wireless data transmission to smartphones; the device achieves up to 48 hours of runtime with USB-C charging, though exact battery capacity is undisclosed.
• Certification status: CE and FCC certifications remain in progress, creating potential risk for hardware revisions that could delay the December 2026 delivery timeline.

Why it matters

The Azume One represents a growing category of modular health hardware that extends the lifespan of existing devices rather than forcing smartwatch upgrades, though its closed-source firmware and undisclosed MCU limit open hardware community engagement. For Linux and open-source users, the absence of any mentioned Linux desktop support, open API, or local-only data processing contrasts with emerging open health platforms, while the Ireland-based GDPR-compliant cloud storage model may appeal to European privacy-conscious consumers. If the nRF52 speculation proves accurate, the hardware could eventually attract open-source firmware efforts similar to those seen with other Nordic-based wearables, though Azume has made no commitments to open sourcing its stack.