|25||LED and Spectroscopy System (for Detecting Aflatoxin in corn)
|Introduction: (idea from Prof. Hart)
Aflatoxins is a toxic component in some grains. Based on its special physical property under LED, like the B-group aflatoxins exhibit blue fluorescence; the G-group exhibits yellow-green fluorescence under ultraviolet (UV) light, We would like to work on design a reproducible prototype LED and spectroscopy system which can detect the aflatoxins in corn kernel.
When a kernel is dropped into a tube, the first LED will be turned on, after the kernel emits fluorescence to the photodiode, the current through the diode will change, this signal will be detected, and the current data will be sent to the laptop. The current signal represents the light intensity. Then the first LED will be off and the second to the sixth LED will repeat this process.
1. Printed circuit board:
A ‘start’ signal to start the cycle (turn on the first LED)
Balancing circuit for 6 LEDs
Interface with the Data Acquisition tool (DAQ) which can be connected to LabView
The DAQ can collect data (represents the light intensity) from the photodiodes to laptop
2. Graphic User Interface (LabView)
Auto on-off system for 6 LEDs based on timing: Each of the LEDs will be switched on one at a time. When the neighboring photodiode detects a kernel, the reading of the spectrometer is triggered for data collection.
Calibration Control: The brightness can be adjusted on the GUI.
Pulsing of LED: The frequency of the LEDs can be adjusted to a frequency needed.
Tools will be used for this project:
Spectroscope (glass tube, LEDs, detector), Eagle, microcontroller, Printed Circuit Board, LabView, Data Acquisition (DAQ), laptop