The firmware update procedure on the Tarot Gimbal page is incorrect. I also think some generalization could be done (remove the v1.4 specifics) to future-proof the procedure if/when a new firmware version comes out.
To update the controller firmware, the Tarot requires that you:
[ol]
[li]Connect the USB dongle to the Gimbal Controller connector.[/li]
[li]Select the appropriate COM port, but do not click “Open COM Port”.[/li]
[li]Click “Open Firmware” and select the appropriate .bgsf firmware file.[/li]
[li]Click “Start Upgrade” and power on the gimbal.[/li]
[li]Wait for the “Firmware Upgrade Successful” message.[/li]
[li]Open the COM port. Verify the firmware version displayed in the bottom left corner.[/li][/ol]
The motor driver firmware should also be updated:
[ol]
[li]Connect the USB dongle to the Motor Driver connector.[/li]
[li]Click “Motor Configuration”.[/li]
[li]Select the appropriate COM port, but do not click “Open COM Port”.[/li]
[li]Click “Open Firmware” and select the appropriate .bgsf firmware file.[/li]
[li]Click “Start Upgrade” and power on the gimbal.[/li]
[li]Wait for the “Firmware Upgrade Successful” message.[/li]
[li]Open the COM port. Verify the firmware version displayed in the bottom left corner.[/li][/ol]
For a better understanding of the Tarot Gimbal, I highly recommend the Tarot T-2D Brushless Gimbal - FAQ over at RCGroups.