[![Arduino CI](https://github.com/RobTillaart/uv-sensor/workflows/Arduino%20CI/badge.svg)](https://github.com/marketplace/actions/arduino_ci)
[![Arduino-lint](https://github.com/RobTillaart/uv-sensor/actions/workflows/arduino-lint.yml/badge.svg)](https://github.com/RobTillaart/uv-sensor/actions/workflows/arduino-lint.yml)
[![JSON check](https://github.com/RobTillaart/uv-sensor/actions/workflows/jsoncheck.yml/badge.svg)](https://github.com/RobTillaart/uv-sensor/actions/workflows/jsoncheck.yml)
[![GitHub issues](https://img.shields.io/github/issues/RobTillaart/uv-sensor.svg)](https://github.com/RobTillaart/uv-sensor/issues)

[![License: MIT](https://img.shields.io/badge/license-MIT-green.svg)](https://github.com/RobTillaart/uv-sensor/blob/master/LICENSE)
[![GitHub release](https://img.shields.io/github/release/RobTillaart/uv-sensor.svg?maxAge=3600)](https://github.com/RobTillaart/uv-sensor/releases)
[![PlatformIO Registry](https://badges.registry.platformio.org/packages/robtillaart/library/uv-sensor.svg)](https://registry.platformio.org/libraries/robtillaart/uv-sensor)


# uv-sensor

Arduino sketch for analog UV sensor.


## Description

![Foo](https://www.tinytronics.nl/shop/image/cache/catalog/products/product-003601/uv-light-sensor-module-200-370nm-80x80w.jpg)
Image courtesy Tinytronics

This small (type-less) UV-sensor is powered by 3.3 .. 5 V so it can be used by almost any microprocessor.

The sensor has an analogue output that is roughly linear with the UV-index (sunlight assumed, see notes)


|  Voltage  |  UV index  |  risk of harm  |  Colour   |
|:---------:|:----------:|:---------------|:---------:|
|   <0.050  |     0      |  low           |  Green    |
|   0.227   |     1      |  low           |  Green    |
|   0.318   |     2      |  low           |  Green    |
|   0.408   |     3      |  moderate      |  Yellow   |
|   0.503   |     4      |  moderate      |  Yellow   |
|   0.606   |     5      |  moderate      |  Yellow   |
|   0.696   |     6      |  high          |  Orange   |
|   0.795   |     7      |  high          |  Orange   |
|   0.881   |     8      |  very high     |  Red      |
|   0.976   |     9      |  very high     |  Red      |
|   1.079   |    10      |  very high     |  Red      |
|   1.170>  |    11      |  extreme       |  Purple   |


From this table the formula is derived (spreadsheet) which is pretty linear between UV 1 and 11.

There is an extended library version which has more functionality and documentation.
- https://github.com/RobTillaart/AnalogUVSensor


#### Notes

Note: The sensor is not calibrated and the table is indicative for sunlight (assumption!)
and therefore not suitable for e.g. medical or industrial usage.

Note: UV radiation will not go through glass, so inside you will most likely always read zero.
This may help to calibrate the zero level of the sensor.

Note: depending on the light source used, the table above is incorrect.


#### Sensitivity

The sensor is sensitive for wavelengths from 200 - 370 nm, 
so mostly in UVB and UVA region and less in the UVC.

https://en.wikipedia.org/wiki/Ultraviolet


## Future

Future development will be done in the library version only.
- https://github.com/RobTillaart/AnalogUVSensor


## Support

If you appreciate my libraries, you can support the development and maintenance.
Improve the quality of the libraries by providing issues and Pull Requests, or
donate through PayPal or GitHub sponsors.

Thank you,