# Infrared Thermographic Signal Analysis of Bioactive Edible Oils Using CNNs for Quality Assessment
## 3 Materials and Methods: Thermographic Signal Acquisition System
The use of the fuse is necessary to protect the system from overcurrent, particularly during the initialisation of connected USB peripherals and thermal modules. Voltage regulation and protection are further enhanced by transient voltage suppression (TVS) diodes and clamping devices such as the USBLC6-2 SC6 array. The microcontroller integrated into the system is an ATMEGA328P, which plays a complementary role to the Raspberry Pi by managing low-level digital interfacing, LED signalling, and shutdown logic. Powered by a regulated 3.3 V line, the ATMEGA328P communicates with external devices through its general purpose input/output (GPIO) pins. In the acquisition and monitoring system, the ATMEGA328P is integrated into the appropriately designed and manufactured acquisition board, as shown in Figure 3 c4. In this configuration, it acts as an intermediary for activation and real-time control functions, providing logical signals to status LEDs and switching elements such as transistors. The use of bipolar junction transistors (BJTs) serves two main purposes. Firstly, they act as electronic switches to drive the status LEDs, which provide visual feedback on the status of the wireless communication and the system's readiness. Secondly, in combination with additional logic gates and the UDS signal, they allow for a controlled shutdown of the Raspberry Pi (Figure 3 c3). The microcontroller-controlled shutdown circuit allows for a safe shutdown sequence, initiated either by a timing algorithm or by a detected fault condition. The signals detected by the thermal camera are managed by an independent electronic device capable of handling a Linux operating system and performing complex numerical processing. The acquired data is then sent to a database that stores it and makes it available to be managed by an online platform. Once the electronic board is created, additional components necessary for data storage and processing are added (Figure 3c). The data collected in real time and the data processed using soft computing techniques are transmitted via a 4G LTE internet dongle (Figure 3 c2) to the monitoring platform [12]. To ensure a stable transmission and good signal quality, the system features decoupling capacitors and base resistors near the RF circuit. The detection unit includes a thermal imaging module, which, in the diagram, is interfaced via an RJ45 connector. The thermal sensor provides critical feedback on the internal temperature distribution of the oil samples, especially when the chamber is subjected to thermal cycles by the Peltier cell (Figure 3 b2). The integrated system for signal acquisition, storage, and transmission presents a different approach compared to other integrated systems [73]. The proposed integrated system aims to allow the operator to analyse signals and data remotely. While the authors of the document [74] chose the Arduino Mega to avoid the memory and power limitations of smaller boards, as the acquisition and filtering of data required a large amount of memory, the proposed document divides the process into two phases. The first focused on acquiring the thermographic signal, trying to eliminate interference and keep the signal unchanged; the second focused on storage and transmission. The division of the process ensures the better quality of the acquired and processed signal, at the expense of increased system complexity.