The blog of a dedicated radio amateur and electronics enthusiast

"Having fun on the air and in the workshop - communicating and creating"

12 January 2021

Another wireless UV Radiation Meter

In the last post, ( 30 September 2020 ), I described my UV radiation meter. That version had Bluetooth (BLE) enabled. Since then I have made a second * version of the meter, but this time having WiFi functionality instead. It is based on the same hardware ( SI1145 sensor & Heltec WiFi Kit 32 module ) as before. As the WiFi Kit 32 module ( see 02 August 2020 ) has both integrated Bluetooth and WiFi, the only changes needed have been to the firmware. I have used an identical enclosure; so the physical appearance is also the same. However, different information is now being displayed on the OLED display.
In use, WiFi typically has a communication range greater than BLE. The meter can be configured either as a Client station connected to an existing network's WiFi router, or as a stand-alone WiFi Access Point; the latter being the more suitable for outdoor use. The meter hosts a web-server, so that a web-page with the UV index measurement can be displayed by connecting to its IP address using a browser on a pc, smart phone, or other WiFi enabled devices etc.
 
A simulated reading displayed on a smart phone

The image above shows the UV Index measurement displayed in a browser. I should point out that the reading was made under controlled laboratory conditions during testing. A background UV Index reading made in an indoor environment would typically be about 0.02 !  

I am calling it the "Spacer-Labs" UV radiation sensor after the location of my laboratory.

* Actually I have also made a third version without any wireless connectivity at all.