# A Distributed Sensor System Based on Cloud-Edge-End Network for Industrial Internet of Things +
## 3 System Model and System Architecture
### Hardware Architecture  
As shown in Figure 6, the Inter-Integrated Circuit (I2C) is a communication protocol used to transmit data between integrated circuits on a circuit board. The ESP32-S2 is a low-power, WiFi-enabled microcontroller with a built-in 240 MHz Xtensa core, making it suitable for IoT applications. The use of I2C+ESP32-S2 technology provides a reliable and  
Figure 5: Schematic diagram of multisensor information technology in data layer fusion. efficient way to collect, preprocess, and visualize data in industrial settings, as illustrated in Figure 7.  
Field studies are important to ensure that the data collection system is able to meet the needs of different industrial settings. The examples provided, such as industrial robot failure monitoring, large manipulator actuator failure monitoring, distributed smart gear box count monitoring, and the online working condition monitoring of a steam turbine generator set, demonstrate the versatility of the system in different applications [39]. In addition, the system can also be used in geographically challenging environments, where it may be difficult for humans to monitor the industrial scenes manually. The dataset generator is designed to create a customized shell based on specific conditions. For instance, if the dataset is intended for underwater scene collection, the shell will be adjusted to account for waterproof performance, density, and other physical characteristics. Similarly, if the dataset is intended for the fault monitoring of a large manipulator actuator, the housing's fixed device will be upgraded to match the manipulator's specifications. The dataset generator can be installed at a specific location on the arm without disrupting its normal operation, and it can collect and transmit data as needed. We evaluated several development board chips and ultimately chose the STM32F103 as the core chip for our dataset generator. The STM32F103 stands out for its powerful ARM core microcontroller, which features either 64 or 128 K bytes of flash memory. Additionally, the STM32F103 boasts low power consumption, built-in controllers, and other features that make it an ideal choice for our project. It offers numerous communication interfaces, including a Universal Serial Bus (USB) and a Controller Local Area Network (CAN), as well as seven timers and two ADCs. It also features a dual timer that allows us to collect sound signals at 4 KHz and acceleration signals at 800 Hz. Overall, the STM32F103 provides the necessary capabilities for our dataset generator while also minimizing power usage and maximizing functionality. Figure 6: Schematic diagram of data acquisition in an industrial setting: IIC and ESP32-S2, with STM32F103 chip as the core collector and ESP32-S2 as the repeater. To collect sound signals, analog signals are first converted using operational amplifiers and then sampled through the MCU's built-in analog converter. For acceleration signals, an external three-axis acceleration sensor is used to collect and transmit data to the MCU via the I2C communication protocol. After analyzing the requirements of our users, we determined that the I2C protocol was sufficient for our needs. To support additional serial port protocols, we also added support for the DTU transfer module. This module can read data from subordinate devices and enable the system to interact with a wider range of devices. For ease of operation and configuration, we chose the JSON format as the configuration standard. This format is easy for users to read and modify and for programs to analyze. FreeRTOS is a leading real-time operating system (RTOS) developed by major chip companies and distributed under the MIT open-source license. It offers excellent reliability and ease of use and includes a core and various libraries for Internet of Things applications across multiple industries. While FreeRTOS is typically designed for use on a single core, the ESP32 processor is a dual-core chip with both a Protocol CPU and an Application CPU.