Detecting System Of Eggs' Electric Properties Based On DSP

Although the egg yield of China has been the No.1 in the world since 1985, the unadvanced technology in egg quality detection has led to the good and bad commercial eggs intermingled and high-quality egg sold as the poors. This not only decreases the social-economic benefit, but may also baffle the competition in the international market. In addition, poor-quality eggs also impair the consumer's health. Therefore, it has become an urgent affair to enhance the nondestructive classification technology, and improve treatment level of commercial eggs.Based on the electrical property detection theory of the organism, one DSP-based egg electric property detection system were researched and designed, which could automatically detect the egg electrical property and display the calculation results according to the user setting frequency. The paper presents the researched system,which includes two parts,hardware system and software system.The hardware system was composed of a signal generator module, an amplitude-phase detection module, an analog-digital conversion (ADC) module, and a input&display module. While in the signal generator module the DDS chip AD9851 was selected to be signal generator as signal source, whose frequency could be adjusted. This chip acted as the peripheral equipment of DSP and manipulated by DSP, so this module could act as an independent signal generator. The amplitude-phase detection chip AD0832 was adopted for the detection module to change the amplitude ratio and phase difference into voltage signal, then transfered the signal to the next module. The 16-bits A/D converter AD7705 was employed by the ADC module, which realized the communication with DSP by McBSP. The DSP+MCU mode was adopted by human-machine interaction module, and AT89S52 was selected by MCU to control the LCD and keyboard input, which had display and input function independent from DSP system. The serial chip TL16C550 was in charge of communication between DSP and MCU. And TMS320VC5402, one additional clock circuit, memory circuit and power circuit are combined to construct one minimum DSP system.The software system was composed of system initialization procedures, showing subprogram, keyboard subroutine, interrupt subroutine, CORDIC tgθcalculation, calculation of the equivalent impedance, etc. The initialization procedures of system mainly initialize AD9851 and AD7705, TL16C550, McBSP and DSP. Of which the DSP initialization was composed of the clock initialization, memory connected with orientation document, and interrupt realization and so on.The egg's electrical property detection system was firstly designed by combing DSP, DDS and AD8302, which pioneers a new approach for measuring electrical property. The designed system can automatically measure the dielectric loss tangent angle and equivalent impedance of eggs in multi-frequency, which provides a new approach for the nondestructiveiy detect egg's internal quality.