For what?

An open device for citizen light pollution monitoring

The Free Dark Sky Meter is a low-cost photometer for measuring the brightness of the natural night sky. It has been designed based on open hardware and software, with several connectivity options and the ability of geopositioning data.

All the data you need

It includes sensors to measure all the necessary attributes, such as light, weather, inclination, or the location of the device.

Real time monitoring

The measurements are updated automatically, which makes it possible to study evolution of the brightness in the natural night sky in real time.

Rechargeable battery

Thanks to the use of rechargeable batteries via USB-C, it is possible to use the device for long-term monitoring in remote locations.

Easy to build…

You can help us in the fight against light pollution by building your own FreeDSM. By using open hardware, all the necessary hardware is sold in specialized stores at a low cost, so it is very easy to build. You just have to follow the steps indicated in the following link.

…and easy to use

All data measured by the FreeDSM is stored on an open platform in the cloud. So if you want to take a look at the state of light pollution in your area, or simply use the data collected, do not hesitate to consult the interactive map at the following link!