The following instructions focus on updating Atrim Stick to a newer version of Z-Wave Plus v2, 800 series firmware. Further help with Atrim Stick is available by following that link.

To successfully update the firmware you will need:

1. Atrim Stick, our USB stick based, Z-Wave Plus 800 series controller running firmware version 7.21 or greater. Note that a bug in Silicon Labs' Z-Wave core presently prevents the update of Z-Wave sticks, including Canadian and USA editions of Atrim Stick and UZB 7, beyond version 7.20. The root cause of this is a conflict between Silicon Labs' firmware and the frequency tuning abilities of select Z-Wave sticks. We shall update this page once resolved by Silicon Labs.
2. A working installation of Home Assistant with Z-Wave JS. The linked guide focuses on setting Home Assistant up with Raspberry Pi; it can also be installed on other platforms including through the use of Docker.
3. The necessary firmware; details on this can be found further on in this guide.
4. To backup your Z-Wave network. Realistically, this is optional but is a heavily recommended step.

Where to find the latest Z-Wave firmware

Z-Wave controller firmware is made and released by Silicon Labs, the owners of the Z-Wave wireless standard. As an 800 series zstick, Atrim Stick and Atrim Stick Mini both use Silicon Labs' EFR32ZG23 chip; it's the firmware for this chip which you will have to specifically download. To do so:

1. Check the firmware changelog to ensure you wish to update.
2. Open Silicon Labs' Gecko GitHub.
3. Browse to protocol > z-wave > gbl within the repository. This will take you to a folder such as github.com/SiliconLabs/gecko_sdk/tree/gsdk_4.1/protocol/z-wave/Apps/bin/gbl
4. Download 'zwave_ncp_serial_api_controller_BRD4204D.gbl' from the gbl repository.

Update Atrim Stick

1. Open Home Assistant in a browser, usually at http://homeassistant.local:8123/
2. Clicking on "Settings" at the bottom left of the page.
3. Click on "Add-ons".
4. Click on "Z-Wave JS UI".
5. Click on "Open Web UI".
6. If not already selected, click the upper most, 'Control Panel' icon in the Z-Wave JS UI menu. It is represented by an icon with 4 squares, one of which is angled.
7. Click the + icon in the bottom right-hand corner to expand the associated menu.
8. Click the purple 'Advanced actions' icon. It is represented by an icon of wand and hovering over it with a mouse should pop up the phrase 'Advanced actions'.
9. Click 'UPDATE' underneath the 'Firmware update OTW' heading.
10. Read and note the risk element of updating Z-Wave firmware. All USB based Z-Wave controllers, including Atrim Stick, utilise an update process created by Silicon Labs. That process is not perfect and it is possible, amongst other issues, to brick a Z-Stick stick having downloaded the wrong forum. Bricked devices are not warranted by Atrim, Home Assistant or the creators of Z-Wave JS.
11. Click the File / Firmware file input field and select the correct firmware you have downloaded from Silicon Labs' GitHub as instructed in the above requirements.
12. Click 'Update'.
13. Allow the firmware updating process to take place; it can take several minutes.
14. Once completed, confirm that a new firmware version shows in Z-Wave JS' control panel for Atrim Stick.
15. Click on Atrim Stick within Z-Wave JS' control panel to expand further available information.
16. Ensure that Atrim Stick is operating under the correct and desired wireless frequency and region by referring to the drop down under 'RF Region'. In some rare instances, new firmware will default to a different region and it is necessary to change it. Click the right arrow to confirm any change. Change no other values.