Desain Penetrometer Digital Berbasis Mikrokontroler ATmega 8535

Abstract

Until recently, most of soil strength measuring instrument still use spring scales penetrometer such as mechanical penetrometer. Mechanical penetrometer was difficult to use and has recording in accuracy because manual reading of spring scales and distance simultaneously. Moreover, mechanical penetrometer need three operator for operation. Therefore, digital penetrometer was developed to solve this problem. Penetrometer digital consists two main components : a electronics components and a mechanical components penetrometer. A mechanical component consists of a handle ring tranducer, penetrometer rod, and cone. Electronic components consists of sensor temperature LM35, strain gage, depth sensor , amplifier, microcontroller ATmega 8535, LCD screen, and battery 9 volts. Methodology use in this research was engineering design based on functional and structural design. Ergonomic of the developed digital penetrometer were condidered based on the Indonesians average anthropometries. Measurement principles the digital penetromter consist of: Compressive force was measured using strain gage sensors mounted on the ring transducer. Shinkage ring transducer strain gage sensor response by the form of the resistance value, because it is too small it takes amplifier, then processed by the microcontroller to be converted into units of kgf. Depth data obtained using ultrasonic sensors ranger. Ultrasonic signal transmission on soil will be reflected and received again by ultrasonic. From measuring the reflection will be further processed by a microcontroller and converted into units of cm. The data read by the LM35 temperature in the form of resistance. After that, change the resistance of the voltage to the microcontroller unit Celsius degree. The third sensor measurement results will be displayed through the LCD and stored in the EMS flash memory. Dimension of the digital penetrometer was 94 cm length, 12 millimeters rod diamater. Penetration of the developed penetrometer was done manually, while measurement of force was done by ring transduser, while depth of penetration was measured by ultrasonic sensor. Result of measurment was displayed on the LCD screen and recorded on EMS data flash memory.