Date
Apr 23, 2026 10:42 AM
Sensors
THS-M45-ZB
We’ve had a lot of fun with the THS-M45 units, which come with BTHome firmware and are ready to use straight out of the box. Now, after testing them for a while, we’re sharing this ultra-high-precision temperature and humidity sensor with Zigbee firmware, and we hope you enjoy using it.
A few notes:
- The firmware uses ppvx’s ZigbeeTLC.
- Press and hold the side button for more than 10 seconds to reset the Zigbee settings.
- Z2M offers better support; we recommend using a Z2M environment.
- The overall signal strength appears to be slightly better than that of the THS-G4.
- The battery level display appears to be inaccurate; it rarely shows 100%. This may be because the motherboard uses a separate LDO, and the current measurement voltage is inconsistent.
Accuracy Improvements (Typical)
Relative Humidity (RH): • SHT40: ~±1.8 % RH typical • SHT45: ~±1.0 % RH typical (better precision) 
Temperature (T): • SHT40: ~±0.2 °C typical • SHT45: ~±0.1 °C typical (twice as precise)
