Some time ago I posted this Raspberry PI DIY Mass Spec using Raman Scattering. It's was something of a cumbersome project though, needing a 3D printer and special heat-resistant plastic giving of carcinogenic fumes during printing. To be blunt it was also not very mobile and interpreting the results was further cumbersome
Recently though, I've been told that Arduino, and it's various sensor packages, has matured to the point where it's a usable alternative. Now I realize that a cigarette...