Firmware updates for our Hammer, H2, and H3, as well as the Magnus and M2 trainers are completed via Bluetooth through the Saris Utility app (iOS/Android).
If you haven't already, download the app from your respective app store - once installed, select Scan for Sensors from the main screen. This will initiate a Bluetooth scan (make sure Bluetooth is enabled on the device), and the respective trainer should show up on the list of Sensors. A message saying "Connecting to [trainer name]" will appear, followed by "Connected" if the connection is successful.
Once the trainer is successfully connected, select Firmware at the bottom of the screen.
If the trainer is on the most recent version of firmware, a bold checkmark will be present next to MCU Firmware Version near the top of the screen. No checkmark indicates it is not on the most up-to-date version.
Tap the box next to Available Versions to show the list of installable firmware versions, select the newest (or desired) version, tap Done, then tap Install - this will initiate the installation. Confirm a successful installation by verifying the displayed Installed Version listing.
A link to our helpful walkthrough videos ranging from updating firmware to calibration can be found on our Smart Trainer Firmware Support page.