Building on the work of other Citizen Science efforts, [doctek]’s entry for the Hackaday Prize promises to detect pollution, identify chemicals, and perform other analyses with a simple handheld device. It’s a spectrophotometer, and [doctek] is putting some real engineering into this build.
A spectrophotometer is one of the simplest devices able to perform spectroscopy, requiring only a light source, a photoresistor, and some means of producing monochromatic light. By putting a sample in front of the photoresistor, the absorption spectrum of the sample can be measured. With this data, it’s a simple matter to identify the sample.
A light and a photoresistor are simple enough, but as with every precision measurement device, the devil is in the details. [doctec] is using new, low-noise, low-offset opamps, and precision references to get his data. Some of the parts in the schematic were actually designed in this century – a far cry from the ‘plug the photoresistor into the analog input’ projects we see so often.
[doctec] is using a Teensy 3.0 to drive the electronics and collect the data, and he already has the mechanics of this build pretty much figured out. It’s a great project that shows off some engineering skill, making it a great entry for The Hackaday Prize.