/members-area/personalblogs/b/blog/posts/in-the-air-challenge-laser-based-dust-particle-counter-using-a-photodiodeMy device is based on article by a A. Morpurgo "A low-cost instrument for environmental particulate analysis based on optical scattering". Note that the OOPA350 schematic in original paper has some mistakes: OP legs are incorrectly numbere...en-USTelligent Community 12