GW4

From AsteroidOS
Revision as of 12:13, 21 December 2023 by Jrt (talk | contribs)


The Samsung Galaxy Watch 4 (LTE) is a round smartwatch that is one of the first ones to contain a bioelectrical impedance analysis (BIA) sensor.

Samsung Galaxy Watch 4
Model number SM-R860, SM-R870, SM-R880, SM-R890 (Wi-Fi only), SM-R865U, SM-R875U, SM-R885U, SM-R895U (USA, LTE model), SM-R895F (Int., LTE model)
Memory 1.5 GB
Storage 16 GB
SoC Exynos W920 dual core 1.18 GHz; GPU: Mali-G68
Sensors
  • Heart rate monitor
  • Bioelectrical Impedance Analysis
  • Accelerometer
  • Gyroscope
  • Barometer
Battery Non-removable 247mAh / 361mAh

Miscellaneous hardware docs

Manually getting into Download or Recovery Mode

Press and hold both buttons until the "Rebooting..." screen appears. Release both buttons and press the power button (red outline) 3 times.

The reboot menu should be displayed. Press the power button to cycle between the options and confirm the selection with a long press (3 seconds).

Skipping initial setup

The pairing and setup of the watch can be skipped by pressing and holding down the Wear OS logo on the pairing screen.

Debugging and Jigs

The device probably exposes a UART via the USB pads if ID is connected to GND with a 619k resistor. This is currently untested.