# IoT-Ready Temperature Probe for Smart Monitoring of Forest Roads
In addition to our area of interest in forest roads, it is possible to extend usage to other areas, e.g., agriculture, where the information on heat transfer and form of irrigation in the vertical direction is of significant value [14]. It is interesting to monitor temperature in the depth of plant roots, as plant roots are known to be stimulated to grow in warmer environments [15]. Monitoring of temperature profiles is commonly used, while several solutions of analog and digital temperature sensors are available. In [16], the authors address the issue of monitoring the temperature of the vertical and horizontal profile of the road surface using low-cost temperature sensors DS18B20 [17; 18]. The purpose of monitoring the temperature profile [10] and logging the measured data was to investigate the freezing effect on the degradation of the road body in cold areas. The distribution of the measuring points of the vertical profile probe ranged from 30 mm to 4 m. They monitored one cycle of freezing and thawing of the subsoil and the effect of the change in atmospheric temperature on the individual monitored layers. In the article by [PERSON] et al. [19], the authorsmonitored changes in soil temperature by application using LM35 temperature sensors, which needed to be calibrated for measurement purposes, due to the minor differences in the characteristics of individual sensors. The authors investigated the effect of using a paper cover film on the change and delay of the soil temperature at a depth of 100 mm depending on the change in outdoor temperature for agricultural purposes. However, in [9; 13], the authors do not present the design of probes for measuring soil temperature, they only present and interpret the results of measurements. In [20], [PERSON] et al. focus on measuring the vertical temperature profile of a water column through changes in physical properties such as the wavelength of electromagnetic radiation, reflection, and filtering of individual components of the light spectrum due to changes in other physical quantities. Presented technologies consist of optical fibers, FBG sensors (fiber Bragg grating) and an interrogator. Changes in the physical properties of specific light components due to changes in temperature are evaluated and based on changes in the characteristics of the monitored spectrum components, they also allow the determination of the ambient temperature after calibration of the device. This technology is unsuitable for temperature monitoring purposes in an environment other than water due to mechanical vulnerability. The problem with deploying IoT devices in a forest environment is powering them without direct connection to the electricity grid. This represents a serious issue and can be solved utilizing locally available renewable energy sources. Wind energy and solar energy are mainly used [21]. Due to these facts, it is necessary to pay increased attention to the overall energy requirements of the installed equipment [22]. Based on the review of available technologies and our previous experience [23] with 1-wire networks, we decided to base the proposed temperature probe on DS18B20 sensors. Such sensors have a wide variety of utilization in temperature measurements [24; 25]. This solution enables unambiguous identification of sensors and thus identification of their position in the probe. The probe is intended for implementation in the area of forest roads for measuring vertical temperature profile of subsoil either as a stand-alone IoT device or in connection with other IoT devices with low energy consumption requirements. Such a design allows utilization in several other areas of interest for monitoring both indoor [26] and outdoor [27] temperature profiles. Its construction allows simple integration into existing devices with 1-wire protocol support. Probe, as such, represents a tiny but essential part of the weather monitoring system for forest roads whose outputs enter into the road management system, as already mentioned above.