To improve our comprehension of the beta Cephei stars, we set up a
photometric multi-site campaign on the open cluster NGC 884 (Chi Persei).
Thirteen telescopes joined the 2005-2007 campaign which resulted in almost
78000 CCD frames. We present an up-to-date status of the analysis of these
data, in which several interesting oscillating stars are pointed out. We end
with the future prospects.
