UV - LTR390

Ultra violet and Ambient sensor

Plugin details

Type: UV

Name: LTR390 UV

Status: COLLECTION E CLIMATE

GitHub: P133_LTR390.ino

Maintainer: tonhuisman

Used libraries: https://github.com/RAKWireless/RAK12019_LTR390 (modified local copy)

Description

I2C UV and Ambient light sensor with UVIndex and Lux calculation.

Configuration

Device configuration

  • Name A unique name should be entered here.

  • Enabled The device can be disabled or enabled. When not enabled the device should not use any resources.

I2C Options

The available settings here depend on the build used. At least the Force Slow I2C speed option is available, but selections for the I2C Multiplexer can also be shown. For details see the Hardware page

Device Settings

  • Read mode: As the sensor has 2 measuring options, the kind of measurement can be selected. By default, Dual mode is selected.

Available options:

Read mode options

  • Dual mode, read alternating UV/Ambient Read both UV and Ambient alternating, and apply separate settings for Gain and Resolution when switching the measuring mode. Calculates both the UVIndex and Lux values.

  • UV reading only Read only UV, and calculate the UVIndex from it (according to manufacurer specification).

  • Ambient reading only Read Ambient light sensor value (ALS), and calculate the Lux value from that.

When selecting a different Read mode, the settings will be saved and the page reloaded, as the available options change when choosing a different option.

UV Only configuration Ambient Only configuration

  • UV Gain The Gain determains the amplification of the signal measured. Depending on the desired range of values, this can be adjusted.

  • Ambient Gain

Gain options

  • UV Resolution The sensor is capable of returning the measurement in different resolutions, as selected here.

  • Ambient Resolution

Resolution options

The time that is needed to determine the measurement increases with the resolution selected. The sensor is only read if a new measurement is actually available.

The Gain and Resolution are factored in for the calculation of the UVIndex and Lux values.

Data Acquisition

This group of settings, Single event with all values, Send to Controller and Interval settings are standard available configuration items. Send to Controller is only visible when one or more Controllers are configured.

Interval By default, Interval will be set to 60 sec. It is the frequency used to read sensor values and send these to any Controllers configured for this device.

Values

The measured values are available in UV and Ambient, and the calculated values in UVIndex and Lux. A formula can be set to recalculate. The number of decimals is by default set to 0 for UV and Ambient, as decimals are not available from the sensor, but after calculating the UVIndex and Lux they are.

Change log

Changed in version 2.0: added 2022-03-26 Initially added.