# Applications of the Open-Source Hardware Arduino Platform in the Mining Industry: A Review
## 2 Arduino in Field Monitoring Systems  
### Overview  
Mining operations are exposed to dangerous environments, regardless of whether they are underground mines or open-pit mines. In underground mines, workers can be exposed to toxic gases, and there is a risk of explosion and fire from coal dust. In addition, there is a risk of roof collapse in underground mines and risk of slope collapse in open-pit mines. Therefore, for safety, it is very important to continuously acquire atmospheric data and geotechnical data from the mine to detect dangers in advance. As Arduino can be combined with various sensors and communication technologies, it is very cost-effective and useful for data acquisition based on IoT technology. Based on  
Figure 1: Process of literature search and classification. the reviewed literature, air quality data is usually measured in underground mines, and geotechnical data is usually measured in open-pit mines. The types of monitoring systems discussed in each article are summarized in Table 2. Figure 2 depicts the applications of these monitoring systems according to the type of mine. The microcontrollers used in the reviewed papers were mostly the Arduino UNO and Arduino Mega. The Arduino UNO is the most popular Arduino board; it is powered by the Atmega328 processor and is compatible with most development board shields. The Arduino Mega is powered by the ATmega2560 processor and has more I/O pins and larger memory space than the UNO. However, this can be disadvantageous, as it is more expensive and larger in size. In some studies, the Arduino Nano was used. The Arduino Nano has the same performance as the UNO, but its smaller size makes it suitable for tight environments. However, as compared to the UNO, the disadvantage is that it cannot be combined with Arduino shields [31]. The type of Arduino board discussed in each article is summarized in Table 2.  
Arduino-compatible sensors can be used (depending on the type of gas) to evaluate the level of gas, which is directly related to worker safety in underground mines. In open-pit mines, geotechnical problems may be more critical than air quality problems, and some studies based on Arduino have been conducted to acquire geotechnical data. As it is difficult to communicate in an underground mine, it is necessary to configure wireless sensor networks (WSNs) to transmit information to the outside. Sensor nodes with computing power can configure a WSN to send data to a main location or sink, where the data can be observed and analyzed [32]. Many of the reviewed studies built WSNs with Arduino-based sensor nodes. Even in open-pit mines, wireless communication instead of physical cables can be useful, in that it is cost-effective and has no physical constraints. For data communication, wireless technologies such as Bluetooth, Wi-Fi, and ZigBee were used. Table 2 summarizes the sensors and wireless communication technologies used in the reviewed studies. Several sensors have been used in many studies to measure atmospheric and geological information. The main functions of these sensors are listed in Table 3.  
Some studies are not only concerned with acquiring data, but also address taking additional measures, such as providing alarms using actuators. Table 2 summarizes the actuators used in each study. Most studies in field monitoring systems are directly or indirectly related to safety at the mining site. Figure 2: Typical applications of an Arduino-based field monitoring system. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Reference** & **Mine type** & **Purpose of Field** & **Microcontroller** & **Sensor** & **Communication** & **Attourer** & **Additional Analysis** \\  & & **Monitoring Systems** & & & & & & Other **Models** & **Additional Analysis** \\ \hline [PERSON] et al.