LUCID upgrade

The upgrade of the ATLAS luminosity monitor, LUCID, is presented. Both the detector and the associated read-out electronics have been improved in order to cope with the LHC luminosity increase foreseen from 2015. The new LHC operating conditions require a careful tuning of the read-out electronics in order to optimize the signal-to-noise ratio. The new read-out electronics will allow the use of digital filtering of the photo multiplier tube signals.