Spectral signature is a characteristic property of a material that represent how the matter interacts with an electromagnetic radiation at different wavelengths. By looking at the reflectance spectra of a material, scientists can not only retrieve vital information like the chemical composition and crystal structure of the material, but also the presence of any impurities or third element within it. The instrument used to derive such spectra is called Spectrometer. While a commercial spectrometer could cost a huge amount of money, Akshat Wahi‘s work is intended to make an open-source tool called WiSci to allow spectroscopy accessible to everyone.
WiSc is a portable spectrometer that communicates to an Android device over Bluetooth to store and visualize the spectral data. It uses Hamamatsu’s C12666MA mini-spectrometer at the front end to collect spectral signature from a target in wavelengths ranging from 340 to 780 nm. The hardware setup includes an Arduino board to read measurements from C12666MA and a HC-05 Bluetooth module for sending the data to the Android device. The android application was developed using Android Studio IDE and is compatible with Android 2.3.3 or higher.
For more detail: DIY portable spectrometer