New Z-Stack firmware boosts performance for large Zigbee networks

Your Zigbee mesh is only as good as its coordinator. Different to the more modern Thread, all Zigbee devices eventually communicate with the controlling hub through a single device: the coordinator. This is why the previously ubiquitous CC2531 is no longer recommended, and Zigbee coordinators based on the Texas Instruments CC2652/CC1352 are the new standard.

Just like any device in your smart home, the coordinator has an updatable firmware. And firmware, as we all know, needs an update every now and again, as bugs are discovered and improvements are implemented. Koenkk, the developer of the popular Zigbee2MQTT bridge, has just released such a firmware update for coordinators based on the CC2652/CC1352, which should increase the performance of large networks consisting of over 100 Zigbee nodes. More specifically, it increases request retry attempts and routing table sizes.

How to update the firmware of your CC2652/CC1352 Zigbee adapter

Updating the firmware of your Zigbee isn't as daunting of a task as you might think. Thanks to the ZigStar GW Multi tool, there is no need to mess around with any scripts or command line commands. Start off by verifying the type of adapter you are using. This step is crucial, as the wrong firmware can brick your device. If you are unsure, you might see the name in the port it uses. To achieve this, open the Zigbee frontend, enter the settings, and select the tab titled serial.

In my case, because I'm using the CC2652RB stick by slaesh, I require the CC2652RB firmware. Koenkk publishes a list of all tested adapters along with their firmware on GitHub. Download the zip file and extract its contents. Now that we have the correct firmware, we can shut down Zigbee2MQTT to avoid any errors from occurring.

Preparing the CC2652/CC1352 Zigbee adapter

Unplug your adapter from the host's USB port and bring it to your PC. If the adapter is fitted in a case, remove it to gain access to the buttons. Hold down the button titled boot and plug the adapter into your PC. Launch the ZigStar GW Multi tool and click the refresh button. It should automatically detect the correct port. If there are multiple options available, check the device manager to find out which one represents the Zigbee adapter.

Next, select the .hex file previously extracted and enable erase, write, and verify. Don't worry about the erase part, your paired devices will all remain as they were. Complete the update by clicking on the start button and watch the progress bar fill up.

Verifying the firmware

Once the flashing process is complete, you can safely remove the adapter from your PC and return it to its original location. Now, you can launch the Zigbee2MQTT frontend and confirm the installation of the new firmware. Open the dashboard, go to settings, and select the 'About' tab. Here, you will find the coordinator's firmware version listed under 'Coordinator Revision'.