Marloun P. Sejera

Standalone Frequency Based Automated Trash Bin and Segregator of Plastic Bottles and Tin Cans

Segregation is the first step to total waste management. Studies show that majority of the population do not segregate wastes because they find it inconvenient. A previous study entitled “Resonant Frequency Based Automated Waste Material Segregator using MATLAB” was done to address this inconvenience. The previous study presented a device that isolates plastic bottles and tin cans through the use of the objects resonant frequency. However, it was computer-dependent and had limitations with regard to the position of drop of the object. Thus, this paper presents a standalone system, an automated trash bin that distinguishes plastic bottles and tin cans regardless of the objects position of drop. The system used a piezoelectric microphone for input signal acquisition and a comparator for noise elimination. Instead of resonant frequency, the system relied on the average frequency response of the object as it hits the platform. The decision process is done by the microcontroller Arduino. The platform used is made of galvanized iron connected to a DC motor that physically segregates the objects. This study will help the community on waste recovery and aims to make recycling more convenient.

Extension of a 3-cm range of transmission and reception of a visible light communication system through varying modulation technique

This paper presents the use of visible light as a means of data communication, utilizing a Light Emitting Diode (LED) for data transmission, specifically the super bright LED and utilizing a Laser diode (LD) module which has a more focused beam and further range. The study implemented a wireless visible light communication (VLC) system that can transmit and receive data with a range of more than 3 cm; through varying modulation techniques, namely Phase Shift Keying (PSK), Frequency Shift Keying (FSK) and, Amplitude Shift Keying (ASK). The process includes using two Arduino modules, one for signal transmission and another for signal reception. The transmitter module is connected to a computer with the Arduino software where data will be inputted for transmission. The receiver consists of a photodiode which sends the intelligence to the Arduino and projects data to the screen. In all of the said techniques, it is observed that the presence of Bit Error Rate (BER) increased as the distance between the transmitter and receiver becomes greater. The farthest distance that PSK can achieve for LED is 9.8 cm and 22.2 cm for laser. In FSK the limit is up until 9.4 cm for LED and 21.4 cm for laser. While in ASK, the BER is unacceptable for all the distances in LED but in using the laser, it can reach as long as 19.4 cm. In general, the researchers were able to extend the transmission distance far greater than 3 cm. minimum distance between the devices.

Design of indoor microstrip TV antenna for integrated services digital broadcast — Terrestrial (ISDB-T) signal reception at 677 MHz

This study will eventually provide a great help to the Philippines in its transition from analog TV to digital TV. Through this study, just before the full adaptation of digital TV transmission, a new indoor digital microstrip TV antenna will be made available for indoor use. The antenna designed is specific to 677 MHz with target characteristics: gain in the range of -5 dB to -2 dB, VSWR of around 1.5, return loss of -10 dB and a bandwidth of 400 MHz. Through the use of simulation tool, High Frequency Structure Simulator (HFSS), the antenna was designed and optimized at 677 MHz. The actual field measurements and testing at the farthest distance of 2000 m around the service coverage area of PTV station helped in validating that the rectangular design has a maximum gain of-2.1623 dB, VSWR of 1.595, return loss of -14.0905 dB, and a bandwidth of 421.9 MHz. With these findings, the antenna designed was limited to a size of 17 cm by 17 cm using a fiber glass printed circuit board as the material.