DESIGN OF LOW COST AND INNOVATIVE DATA ACQUSITION IN SOIL MECHANICS TESTING USING OPEN SOURCE HARDWARE

Abstract

Sensors are increasingly in our lives, microprocessortechnology is evolving and open source hardware is becoming widespread.Preparation of experimental setups using open-source hardware reduces researchcosts. Arduino is an open source development platform which is operated with anopen source software. It consists Atmel AVR microcontroller, circuit elementsfor interfacing, a 5 volt regulated power and a 16MHz crystal oscillator. With10 bit ADC, it can read 0-5V voltages in 1024 steps. There are at least sixanalog inputs and 13 digital input-output pins, which can meet the channelrequirements of a soil mechanics laboratory. Together with the"do-it-yourself" civil movement, the use of these platforms by youngengineers in particular will gain experience that can be helpful in differentapplications. This study explains design and development of a low cost and opensource data acquisition system for soil mechanics laboratories. The mainadvantage of making laboratory scientific equipment by using open sourcehardware is that, shared design promotes a better design as the scientificcommunity can contribute to its design. In modern geotechnical laboratoriessensor readings are essential for many setups such as consolidation, uniaxialcompression, triaxial compression and shear box tests. Moreover, some testsneed temperature and humidity conditioning. In the setup, Arduino Uno model wasused as a microcontroller. Sensors with a 5 volt supply can be connecteddirectly, and a booster circuit is added to the circuit for sensors requiring a10 volt supply. The data of sensors having 0-5 volt input signal can be directlydigitized. For sensors with millivolt output such as load cells, a drivercircuit is added. The code is written in the C ++ language. The acquired dataare tabled on an Excel sheet and it is possible to process the data forspecific needs.