Embedded Lab

Spectrophotometers are used in scientific studies to quantitatively measure the absorption spectra of a sample object by passing a beam of light through it. [doctek] is a contestant for Hackaday Prize 2016 and his entry for the contest is a DIY Spectrophotometer using Teensy.

Building on some good work by others (https://publiclab.org/wiki/spectrometer andhttp://myspectral.com/ among others), this spectrophotometer has it’s own bright light (White LED), and uses a lock-in amp and photodiode as a sensitive detector. A Teensy 3.1 is used as the controller and the interface to transfer data to a pc for further analysis. The LED is a high power white one chosen for it’s broad light spectrum. The driver can be programmed (via a resistor) for varying power levels and the unit can be rapidly switched on and off for use with the lock-in amp. A piece from a DVD mounted on a servo motor creates the light spectrum that is moved past a slit, shines on the sample cuvette, and then on the photodiode.