As you are not reading form the sensor directly, but through an amplifier.
An offset on the output for zero UV, is probably due to the fact that most OP-amps cannot drive their outputs to gnd potential.
So a fixed offset is programmed into the sensor module to make sure all modules output the same calibrated levels.
The example given in the above link, compensates for that offset.
Hi Tom, thanks a lot for your quick reply! I saw that guide however my GYML8511 UV Sensor should have this extra pin with the reference and also a voltage regulator that the basic ML8511 doesn't have and this should solve the issue.
The sparkfun example requires a breadboard to make all the connection I would like to avoid this using the GYML8511 version. I was wondering if anybody found an easy fix, I was thinking that because it is linear to take the dark current and subtract it...
So you want to use the raw IC rather than the module.
The site you link in post #1 gives you a schematic of what is on the module.
All you need to do is incorporate those components into your design.
If you already have a 3V3 supply then you don't need the 3V3 LDO.