Design of a highly affordable and reliable data acquisition unit system dedicated to experimental research and education

Most experimental research is based on trials that need a measurement acquisition chain (acquisition unit, sensors, and IoT). The units of acquisition employed in research are becoming more accurate and complex. However, they do have other disadvantages: they are rather costly, They are expensive, lack an Ethernet connection, the drivers' source codes are not modifiable, and are designed to work with very specific sensors, making them incompatible with other sensors on the market outside those proposed by the device manufacturer. This article introduces the DL2C datalogger, which combines a previously unique mix of open source codes and inexpensive computer hardware. The acquisition unit is self-contained, portable, easy to build, and connects to a wireless internet network with a very accurate data values collection. Its operation consists of a well-balanced mix of hardware (i.e., Arduino Nano, Arduino Uno, and Raspberry Pi) and software (i.e., C, Python, LabView). According to the state-of-the-art realized, the combination of an Arduino, a Raspberry Pi, and a LabView environment is very original. The Arduino Uno enables the collection and visualization of a wider variety of measurement ranges directly on the acquisition unit. The Arduino Nano regulates the power supply and assures the security of the DL2C electronic circuit. The Raspberry Pi facilitates the DL2C to function without the assistance of a computer. Finally, the LabView graphical interface is utilized to manipulate and visualize the central unit's data remotely. The DL2C measures between [-5V; +5V] with an average absolute error of 0.02V for Volt signals and 4.98 mV for milliVolt signals. An application example using the datalogger was presented and the DL2C subjected to a S.W.O.T study to identify the strengths, weaknesses and possible future improvements of the DL2C database acquisition.