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How to use the lawn-tech UVB Power Meter (UVB Sensor Hat + M5StickC Set)


This page explains how to use the UVB Power Meter (UVB Sensor Hat + M5StickC Set) sold at BOOTH.

It can measure ultraviolet B wave (UVB), which is necessary for reptile breeding, etc. It does not react to UVA.

For specifications and technical information, please refer to the lawn-tech UVB Meter (UVB Sensor Hat + M5StickC Set) support page.

Check the items included in the package

Make sure you have the following items.

  1. UVB Sensor HAT
  2. M5StickC (with UVB measuring program written)
  3. USB cable (Type A-C)

Installing the HAT

With the power of the M5StickC turned off, insert the pin header of the UVB sensor HAT into the pin socket of the M5StickC as shown in the figure.

Be careful not to insert it in the wrong direction. If you are concerned about the wobble of the HAT part, use double-sided tape or adhesive to attach it.


Charging the M5StickC

The M5StickC has a built-in battery. It can be recharged by connecting it to a PC or AC adapter with a USB cable.

How to turn on the power

When the built-in battery is well-charged, press the power button to turn it on.

Power Button

How to turn off the power

Press and hold the power button (for more than 1 second) to turn off the power.

Auto power off function

The power will be turned off automatically if the unit remains stationary and no operation is performed for more than 5 minutes.

Measurement method

Measurements can be taken as soon as the power is turned on. Measure with the sensor window facing the UV source.

Do not look at the UV source with the naked eye. Failure to do so may cause damage.

Sensor Window

How to read the display

  1. The power of UVB is displayed. The unit is uW/cm^2. If the measured value is 1999 uW/cm^2 or higher, 1999 is displayed.
  2. The UV index is displayed. 13 or higher is displayed as 13+. The UV index is calculated only from the UVB measurement results, so it may not be accurate in conditions other than sunlight.
  3. Displays a bar graph corresponding to the UV index (0~13).
  4. "HOLD" is displayed when the measured value is being held.

Data hold function

Press the button A or B to hold the current measurement value.

Press again to release the hold.


Calibration (zero adjustment)

When the power is turned on while pressing button B, the adjustment is made so that the sensor output at that time is regarded as 0. The adjustment result is saved in the non-volatile memory, so it is valid even when the power is turned off.