Convert the firmware for the THS-M45 (BLE, BTHome) to that for the THS-M45-ZB (Zigbee)

Date

Sep 18, 2026 3:05 PM

Sensors

THS-M45THS-M45-ZB

Background

In very rare instances, we may have sent the incorrect M45 BTHome firmware to users who requested the Zigbee firmware. In such cases, the firmware can be restored via an online OTA update.

Distinguishing Features

Generally speaking, for M45 devices running BTHome firmware, their identification labels (yellow labels) will bear the marking ‘MJ6 XXXX’, where XXXX represents the last four digits of the MAC address, which also serves as the default name used by BTHome to identify the device.

General identifiers for BLE firmware

They correspond to this information in the HA device properties.

The tags in the Zigbee firmware, on the other hand, are very long:

This is the identifier for the Zigbee initialisation firmware

They correspond to this section of Z2M

How-To: Converting M45 BLE firmware to Zigbee

💡

This method is limited to converting BLE firmware to Zigbee; if the reverse is required, additional Zigbee local OTA configuration is needed, which is beyond the scope of this discussion.

Preparation: The tool required here is Telink online configuration tool(From Atc and Pvvx). You will need to use the Chrome browser and position the sensor as close as possible to your computer, which must be BLE-enabled.

https://pvvx.github.io/ATC_MiThermometer/TelinkMiFlasher.html

First, identify the device you wish to update. The device used in this demonstration is the MJ6 8E6E. In the web-based tool, click ‘Connect’ and wait for the list to appear gradually (you can set a filter prefix of ‘MJ6’ to reduce the number of irrelevant BLE devices). As the MJ6’s BLE firmware broadcasts very slowly, you will need to be patient whilst it picks up a signal.

The target device for this project is this 8E6E.

By setting the filter prefix to MJ or MJ6, you can significantly reduce the difficulty of searching through an excessive number of BLE devices.

The device we need has appeared; tap ‘Pair’.

Once pairing is complete, the thermometer information will be displayed; at this point, select the Zigbee firmware.

This is the target firmware to be replaced

Click to start Flashing

For the pop-up box, simply select ‘OK’.

The OTA update is now in progress!

You can see the OTA progress here – it’s quite cool.

At the bottom, you can see the details of the operation; the message ‘Update done’ at the end indicates that the update has been completed. At this point, the M45 will automatically restart, and the connection will be lost.

Enable ‘Join’ in Zigbee2MQTT and wait for the device to appear!

Bingo, this is now the Zigbee version of the M45.