Abstract: This paper designs a networked automatic meter reading system based on an embedded system, focusing on the system's hardware and software composition and design features. This system can be used to collect data from meters of electricity, water, gas, and heat in buildings and control energy-consuming equipment in households. Automatic meter reading is beneficial for energy management departments to achieve energy monitoring and management, improve energy efficiency, and is of great significance to China's sustainable development. Keywords: Automatic meter reading system, embedded system, wireless communication technology, intelligent data acquisition device 1 Introduction Currently, the world is experiencing energy shortages, and energy conservation is of great significance to China's sustainable development. A State Council decree issued on September 1, 2003, stipulated that water, electricity, gas, and heat supply units should read meters to individual households, making this an inevitable trend. At the same time, departments such as electricity, water, gas, heating, and property management are also urgently demanding a transformation of the traditional manual door-to-door meter reading method due to the need for data statistics and fee management. Traditional meter reading (water, electricity, gas, heat) requires meter readers to periodically visit each household to collect data, calculate fees, and then collect more from each household. This method is prone to errors, labor-intensive, inconvenient, and unsafe. Applying the latest research results in computer technology, network technology, and microelectronics to the meter reading system allows for automatic data collection, scheduled transmission, and real-time monitoring without on-site personnel, saving time, manpower, and resources, and improving work efficiency. Simultaneously, real-time user usage data facilitates energy monitoring and management by management departments, improving efficiency and forming the foundation for future energy distribution automation, while also contributing to the modernization of management departments. 2. System Structure and Overall Scheme Design Currently, most residential communities in China use a one-meter-per-household system, which determines the following main characteristics of the meter reading system: numerous data collection points, large data volume, and dispersed nature; the system is a wide-coverage communication network. This paper addresses these characteristics by adopting a distributed architecture to design a networked automatic meter reading system. Figure 1 shows the overall structure of the automatic meter reading system. The lower layer of the system consists of user metering instruments, intelligent data collectors, a monitoring center, and communication channels. An intelligent data acquisition device based on an embedded system is used for data acquisition and control of household energy-consuming equipment. The monitoring center monitors, measures, and bills user meters, generating data files and periodically sending payment notifications to users via SMS or email. The system's communication channels mainly include the communication channel between the monitoring center and the intelligent data acquisition device, and the communication channel between the intelligent data acquisition device and user meters. The lower layer (between the intelligent data acquisition device and user meters) uses short-range wireless communication; the upper layer (between the monitoring center and the intelligent data acquisition device) uses GPRS wireless communication. 3. Intelligent Data Acquisition Device Design This system uses an intelligent data acquisition device based on an embedded system. This data acquisition device acts as the core of the entire system, serving as a bridge. The intelligent data acquisition device uses the SUMUNG S3C44B0X chip as its hardware core, and is equipped with simple peripheral circuitry to achieve "four meters in one" data acquisition and control functions for household energy-consuming meters, namely: ① Wireless communication with each meter via a Bluetooth communication module. It acquires conditioned pulse input signals and analog current and voltage input signals, organizes and saves the meter data, and awaits data transmission. ② The data acquisition unit packages the data into IP packets and then connects to the GPRS network via the GPRS interface to transmit the data to the monitoring center. ③ It receives control signals from the monitoring center and monitors the room for gas leaks, fires, or prolonged periods of absence by various sensors. When a user defaults on payment or encounters an anomaly, it controls the shutdown of the user's energy-consuming equipment. The hardware composition of the intelligent data acquisition unit based on the embedded system mainly includes: a central processing unit, a data acquisition and storage module, a wireless communication module, various sensor monitoring units, an energy-consuming equipment control module, and a status display section. The connection method between the peripheral circuit of the intelligent data acquisition unit and the S3C44B0X chip is shown in Figure 2. 3.1 Data Acquisition and Storage Module Based on a comprehensive consideration of the product's cost-effectiveness, this system selects the Samsung 32-bit microprocessor S3C44B0X chip. An AMD AM29V160 FLASH chip is selected as the data storage component, with its address set from 0x0000,0000 to 0x001f,ffff. The sector distribution is as follows: operating in double-byte mode, there are 36 sectors in total. Except for the first 8 sectors, which are 8KB in size, the remaining sectors are all 64KB in size. Since a small operating system needs to run in the data acquisition unit, the memory requirements are higher than those of a typical microcontroller system. This system uses HYUNDAI's HY57V641620 SDRAM, with a capacity of 16 x 4 Mbit and a data width of 8MB. Its address is set from 0x0c00,0000 to 0x0c7f,ffff. Only two registers of the S3C44B0X (BWSCON and BANKCON6) need to be configured for it to function properly. The S3C44B0X integrates a 10-bit CMOS digital-to-analog converter (ADC), which includes an 8-channel analog input, an automatic zero-crossing comparator, a clock generator, a 10-bit continuous approximation register (SAR), and an output register, and provides software-selectable operating modes. This system fully utilizes the on-chip ADC of the S3C44B0X chip, connecting it to the output of the instrument's front-end transformer. The acquired standard analog signal is then introduced as the most important input to the system, serving as the information source for data analysis and transmission. It's important to note that this on-chip ADC lacks a sample-and-hold circuit; therefore, the input signal frequency range is limited to 0-100Hz. If a higher frequency input signal is required, an external sample-and-hold circuit can be added. 3.2 The wireless communication module transmits data between the intelligent data acquisition unit and the user's metering instrument via short-range wireless communication. The system uses the Nordic transceiver chip nRf401. The nRf401 is a single-chip UHF wireless transceiver operating in the 433MHz ISM band. It employs FSK modulation and demodulation technology, achieving a maximum operating speed of 20kbps and adjustable transmit power up to +10dBm. The antenna interface is designed as a differential antenna, facilitating the use of low-cost PCB antennas. This chip also features a standby mode for greater power saving and efficiency. The nRf401 connects directly to the S3C44B0X via a serial port, and its circuit diagram is shown in Figure 3. Figure 3: nRf401 Circuit Diagram. The monitoring center and the intelligent data acquisition unit use GPRS wireless communication. Considering cost-effectiveness, the SIEMENS TC45 module is selected. The TC45 module is a wireless communication module based on a GSM/GPRS engine. It can operate at two frequencies: 900MHz and 1800MHz. It has nine general-purpose interfaces, two serial ports, and a voice module. This module embeds the TCP/TP protocol, and users can directly develop software for the TC45 module through the J2ME platform. The hardware composition of the TC45 communication module is shown in Figure 4. Figure 4: TC45 Communication Module Hardware Composition Block Diagram. Figure 5: System Software Functional Block Diagram. 3.3 Various Sensor Monitoring Units: Plasma smoke detectors are used to detect fire signals, carbon monoxide detectors are used to detect gas leak signals, and infrared detectors are used to detect whether there are people in the room. The monitoring signals from various sensors are transmitted wirelessly to the intelligent data acquisition terminal via the S3C44B0X as the basis for controlling energy-consuming equipment. 3.4 The energy-consuming equipment control module connects to water, electricity, gas, and heating control devices via the S3C44B0X's general-purpose I/O ports. Based on resident payment status and the occurrence of unforeseen events, it controls the on/off status of the corresponding devices, achieving automatic household energy management, especially energy-saving control during water and power outages when the house is unoccupied for extended periods. 4. System Management Software Functions In this system, management software is developed using Delphi. It collects data and sets parameters from meters via a wireless communication network, processes and analyzes the obtained data to monitor and control the meters. The system employs a master-slave communication structure between the management computer and the data acquisition units, allowing the management computer to communicate with each data acquisition unit. The system uses a multi-point polling communication method; the management computer calls the data acquisition units according to their addresses, and the data acquisition units, after receiving the calls, upload the data stored according to the communication protocol to the management computer. The system software functional block diagram is shown in Figure 5. The system management software mainly consists of remote automatic meter reading, database management, user query, network billing, remote monitoring, payment notification, and report printing. 5. Conclusion The networked automatic meter reading system designed in this paper adopts advanced technologies such as Bluetooth short-range wireless communication, GPRS wireless communication, and embedded systems. This system transmits data information through a wireless communication network, featuring advantages such as no wiring required, low workload, large data transmission capacity, high accuracy, and low communication costs. It has broad application prospects and can create significant social and economic benefits.