Looking inside the Samsung Gear Fit 2 Pro Fitness Band
Electronic engineering teardown conducted by Ottawa-based Tech Insights
Tech Insights has seen its share of smart watches and fitness bands, including a couple, if not all, of what Samsung has on offer. One of their early fitness bands, the 2014 Gear Fit SM-R350 was followed up with the Samsung Gear Fit 2 SM-R360. Both were well designed and offered a range of features, but any activity involving water left them both… dead in the water.
The first Gear, the Gear SM-R350, included Bluetooth connectivity, and was based on an STMicroelectronics ARM Cortex-M4 MCU. The follow-up Gear Fit 2 SM-R360 upgraded to include WiFi and GPS and was based on a Samsung Exynos 3250 Applications processor (AP). But this year Samsung jumped in to the deep end and upgraded the Gear Fit 2 series to the new 5 ATM waterproof Gear Fit 2 Pro SM-R365. It includes everything offered in the SM-R360, plus the addition of swim activity tracking.
TechInsights has already torn down the Samsung Gear Fit2 Pro SM-R365, so let’s take a short stroll and go through what we found. First, we will look at everything that was the same between the Gear Fit 2 SM-R360 and the Gear Fit 2 Pro SM-R365.
Application Processor (PoP)
The SM-R365 has the same Exynos 3250 Dual-Core Applications processor in a Package on Package (PoP) assembly underneath the same Samsung KMFJ20005D-A213, an eMMC with 4 GB MLC NAND Flash and 512 GB LPDDR3 SDRAM mixed-memory package.
Navigation and Wireless SoC
Here, too, the Gear Fit 2 and the Gear Fit 2 Pro fitness bands use the same GNSS hub and WiFi / Bluetooth SOC components. Both have the Broadcom BCM4774 for GPS, GNSS, Glonass, Galileo, and Beidou support, and the same Broadcom BCM43436 for WiFi / Bluetooth connectivity. Even though Broadcom sold their IoT business to Cypress Semiconductor, which we understood to include the Broadcom Wearable portfolio, we continue to see WiFi / Bluetooth SoCs in Wearables bearing the Broadcom package marks.
The first sensor we are going to mention is the STMicroelectronics LSM6DS2, featuring a 3D accelerometer and a 3D gyroscope. Again, this is the same STMicroelectronics MEMS sensor used in the Gear Fit 2 SM-R360.
Pressure Sensors – a One-Two Punch?
Here is something sort of new. We say ‘sort of’ because we first found the same STMicroelectronics LPS22H pressure sensor in both the SM-R350 and SM-R360 smart fitness bands.
What is new however, is the second pressure sensor we found: the STMicroelectronics LPS33HW, a water-resistant MEMS pressure sensor. The LPS33HW is how Samsung upgraded from the Gear Fit 2 IP68 water-resistance rating to the 5 ATM rating, and added swim activity tracking in the Gear Fit2 Pro SM-R365.
Yes, we found not one, but two pressure sensors. We will proceed with our full Deep Dive teardown report due early next year and strive to understand how the pair of pressure sensors work together, if they work together at all, or if each has its own separate purpose.
Other wearables with swim tracking, like the Casio WSD-F10 use only one sensor – the Alps HSPPAD132A – while the popular Finnish-designed Polar M600 can also track swim activities without a using a pressure sensor at all. Instead, the Polar M600 tracks swimming activities using an app and the STMicroelectronics LSM6DS2 6-axis MEMS accelerometer & gyroscope. Yes, the same STMicroelectronics LSM6DS2 found in the Gear Fit 2 fitness bands.