(1) Download the latest firmware here.
(2) Unzip the files and copy the files to the root folder of a micro SD card
(3) Disconnect Sentry from power and insert the micro SD card into Sentry (where is the SD card slot?). If Sentry was installed, you will need to unmount it from the base plate.
(4) Power up Sentry again (you can also use a 5V2A micro USB adapter to power it up). Immediately after Sentry is connected to power, long-press the RESET button at the back of the doorbell body for about 3 seconds. You should now see the doorbell indicator light flashing in full circle.
(4) Wait for about 2 minutes. When you hear “system startup” and “waiting for connection” at the end, the firmware update is successful.
(5) Please remember to unmount the SD card and delete the firmware update files before using it on Sentry again. Otherwise Sentry will enter firmware update every time it restarts