# Applications of the Open-Source Hardware Arduino Platform in the Mining Industry: A Review
## 3 Arduino in Wearable Systems
### Human Bioinformation
This study redesigned and evaluated a tactile vocabulary via a vibrotactile belt to assist navigation in an underground mine for the safety of miners. In addition, they designed a vibrotactile display shaped like a belt. Thus, the mine worker could wear the tactile display, improving the ease of its use. Moreover, it is more appropriate to deliver tactile cues to a user's waist when the task concerns navigation. An Arduino Mega board was used to control the vibrators. During the navigation task, the heart rate data were collected using a Polar heart rate monitor interface (SEN-08661). The results of a virtual simulation of an emergency in an underground mine showed that the average heart rate increased between trials for all users. As the users performed the navigation in a standing position, the variation in their heart  
Figure 9: A flowchart showing the operating principles of the wearable safety management system. rate could have been associated with fatigue or anxiety. Nevertheless, heart rate data could be used to indicate important characteristics for a sense of immersion in virtual environments. Some studies have designed smart helmets for measuring and monitoring both the air quality in the underground mine and the heart rates of mine workers. [PERSON] et al. [29] designed a prototype intelligent helmet for mine workers, intended for monitoring heart rates and air quality. The system comprised three environmental sensors related to gas (MQ5), temperature, and humidity (HSM-20G) in an underground mine and heartbeat detection sensor (ear clip kit). This kit was highly sensitive, yet consumed little power. The measured heart rate could be displayed on a screen via a serial port and could be saved for further analysis. The Arduino Mega (ATmega2560) microcontroller and ZigBee modules were selected to send or receive all of the electrical signals. After rapid changes in the environmental parameters in underground mines, it was possible to alert the workers via a buzzer on the helmet, and the time series signals could be displayed on an LCD or laptop at a ground station by the ZigBee module. In a similar way, [PERSON] et al. [67] designed a smart helmet system for the security of coal mine workers. The system was divided into a transmitter section and receiving section. An Arduino (ATmega328p) microcontroller was connected to two environmental sensors for monitoring carbon monoxide and temperature inside the coal mine, a pulse rate sensor for monitoring the heartbeat of miners, and a global positioning system (GPS) sensor for locating the position of workers. For the wireless network, HC12 (a half-duplex communication module) was used for the data transmitter and receiver. A display screen was used to display the parameters. A buzzer was designed to trigger a buzzer under harmful and dangerous conditions. [PERSON] et al. [68] developed a helmet-type safety management system for destructive event detection, as well as for detecting air quality and heart rates of mine workers. However, the system design, including the types of sensors (air quality, such as for gas, humidity, atmospheric pressure, and temperature; destructive event detection, such for as falling rocks; heart rate), microcontroller (Arduino Nano), communicator (ZigBee S2C), and actuators (buzzer, LED indications on the helmet, and alerts to supervisors) were similar to those in previous studies. The system was developed by programming based on Arduino IDE and Python.