Abstract: Data acquisition is an essential means of detecting battery temperature. Program-controlled data acquisition systems are a relatively advanced acquisition method. This paper uses thermocouples as temperature sensing elements to acquire battery temperature signals to construct a microcontroller-based temperature acquisition system, which effectively achieves the desired purpose. Keywords: Data acquisition, microcontroller, battery temperature 1 Introduction To ascertain the various characteristics of a test object, we often need to use various instruments and methods (direct measurement or telemetry) to obtain various measurement results (data). However, these data contain transformation errors, equipment errors, and errors caused by various interferences introduced during transmission (when using telemetry). Moreover, the amount of data is usually large, with meaningful and meaningless parts mixed together. Direct application without selection will inevitably cause great inconvenience. In addition, in many cases, further processing (i.e., data transformation) is required to provide a more explicit and direct data form (such as spectral analysis of input vibration waveforms). All these problems must be solved through data acquisition and processing. In order to detect the temperature of the storage battery, this paper uses thermocouples as temperature detection elements to collect the battery temperature signal to construct a microcontroller temperature acquisition system, which achieves the required purpose well. 2 Data Acquisition In a broad sense, the main contents of data acquisition and processing should include the following aspects: (1) Data acquisition: mainly solving the problem of converting non-electrical quantities into electrical quantities and the problems of multiplexing, conversion between analog and digital forms of data. (2) Data recording: data storage is a very important issue. Currently, magnetic recording is an effective way to store large amounts of data. (3) Data processing: including preprocessing, data verification and data analysis (reprocessing) steps. Data acquisition should include the entire process of converting various measured non-electrical quantities into electrical quantities and combining them reasonably, and then providing a coded multi-channel signal. The problem of converting non-electrical quantities into electrical quantities is the problem of sensors; and the key to reasonably combining them into multi-channel coded signals lies in the two issues of sampling frequency and coding accuracy. Typically, the acquired data is a data form resulting from the conversion of certain physical quantities of the measured target from non-electrical quantities to electrical quantities, followed by amplification or attenuation, sampling, encoding, and transmission. The primary task of data processing is to restore these data forms to their original physical quantity forms and, as far as possible, to their variations. Furthermore, due to imperfect equipment performance and the influence of external interference and noise, each of the aforementioned stages introduces some error into the acquired data. Therefore, another important task of data processing is to employ various methods (such as outlier removal, smoothing, and filtering) to eliminate these errors to the greatest extent possible to obtain the most accurate data. Another task of data processing is to perform certain transformations on the data itself (such as calculating the mean or performing a Fourier transform), or to perform certain operations between related data (such as calculating correlation functions), thereby obtaining secondary data that better expresses the intrinsic characteristics of the data. Data acquisition systems are used to measure and record signals obtained in two ways: signals obtained from directly measured electrical quantities and signals obtained from sensors. Data acquisition systems (whether analog or digital) largely depend on the intended application of the recorded input data. Generally, analog data systems are used when high bandwidth is required or lower accuracy is permissible; digital systems are used when the monitored physical process is slowly changing (narrowband) and high accuracy and low cost per channel are required. The complexity of digital systems ranges from single-channel DC voltage measurement and recording systems to advanced automated multi-channel systems capable of measuring numerous input parameters, comparing them to pre-set limits or conditions, and performing calculations and judgments on the input signals. 3. Program-Controlled Data Acquisition Systems Data acquisition systems are transitioning from traditional sequential control systems to program-controlled data acquisition systems. These systems consist of both hardware and software. The acquired data is stored in memory. Depending on the specific data acquisition task, the system's performance, such as the number of channels, sampling rate, and signal frame format, can be modified through programming to meet the needs of various acquisition tasks. Commonly modifiable system parameters in program-controlled data acquisition systems include: acquisition points; sampling rate; data word length; gain; and frame format. It mainly consists of four parts: a remote control acquisition unit, a frame format generator, a controller, and a bus. The system can have multiple remote control acquisition units, using a distributed approach, placing each unit at a different acquisition location. Each remote control acquisition unit is connected to the controller via address lines, data lines, and clock lines. The controller sends channel address codes to each remote control acquisition unit at the total sampling rate via the address lines. To ensure that only a specific channel in a unit with a matching address is addressed and sampled within a sampling period, each channel has a unique address code. This ensures that at any given time, only a specific channel in a unit with a matching address code is addressed and sampled. However, due to functional limitations, this system operates using a polling method, making it difficult for general users to use and design, and system expansion is impossible. With the development and application of microprocessors, various chips with different functions have emerged, and the hardware of a program-controlled data acquisition system can be composed of various chips such as a central processing unit (CPU), memory (RAM and ROM), I/O interfaces, and A/D converters. Then, with the corresponding software, a complete data acquisition system can be formed, and it is possible to achieve performance indicators such as miniaturization, low power consumption, long life and high reliability. If a standardized microprocessor is used as the controller of the data acquisition system, the hardware design workload of the designers can be greatly reduced, and the price, size and weight of the system will be greatly reduced. In terms of working mode, since the interrupt working mode can be adopted, the various parts of the data acquisition system can be componentized and modularized. When each module needs the microprocessor to serve it, it makes an interrupt request to the microprocessor. After the interrupt is acknowledged, the microprocessor can serve the module. In this way, each module has relative independence, thus giving the system greater versatility and scalability. The basic structure of the microprocessor data acquisition system is shown in the figure below: In order for the system to work normally, the following functional software should generally be included in the data acquisition system: (1) System monitoring program: mainly used for the initial startup of the system and simple error checking during system debugging. (2) Initialization program: used for the initialization of system parameters and the initialization of the interfaces of each plug-in board of the data acquisition system. (3) Acquisition program: This program is usually embedded in ROM and is a program that acquires data according to the acquisition format. Depending on the system requirements, a system can be equipped with multiple programs of different acquisition formats to adapt the system to various working conditions. (4) Output processing program: Processes the acquired data and then outputs it. (5) Command control program: It is a program that controls the working status and working mode of the data acquisition system according to the commands issued by the operator. 4 Battery temperature data acquisition system As an auxiliary power supply device, the battery works with the generator to supply power to the power-consuming device when the engine is not working or the output voltage is lower than the battery voltage, and when the generator output power cannot meet the needs of the power-consuming device. The battery discussed here is an important power supply device for a certain weapon system. It is a new type of lead-acid battery and is a low-maintenance type. Since the battery is used as a backup power source in practical applications, it is a key device to ensure uninterrupted power supply. Therefore, the detection of battery performance is very important. Temperature measurement uses a thermocouple sensor. After amplifying the thermocouple signal, the data is processed by the 8031 ​​microcontroller (L9290425). The acquisition and amplification circuit is shown in the figure. The sampling program flow of the microcontroller temperature acquisition system using thermocouples as temperature sensing elements is as follows: The selection of the type of temperature sensing element and transmitter is related to the controlled temperature and accuracy level. Copper-constantan thermocouples are suitable for temperature measurement ranges from -200℃ to 350℃. The transmitter consists of a millivolt transmitter and a current/voltage transmitter: the millivolt transmitter is used to convert the voltage output by the thermocouple into a current in the range of 0-10mA; the current/voltage transmitter is used to convert the 0-10mA current output by the millivolt transmitter into a voltage in the range of 0-5V. The interface circuit of the 8031 ​​includes chips such as the 2732 and ADC0809. The 2732 can be used as an external ROM memory for the 8031, and the ADC0809 is the input interface for the temperature measurement circuit. (Its system schematic diagram is as follows) Several ways to improve the data acquisition speed of a microprocessor system: (1) Select a high-speed microprocessor (2) Select a suitable input/output method (3) Adopt a multi-microprocessor system structure 5 Conclusion The battery temperature detection system based on a single-chip microcomputer widely adopts multiple technologies such as computer, automatic testing, microelectronics and automatic control. It not only has the advantages of convenient, simple and flexible signal acquisition, but also can greatly improve the technical indicators of the measured temperature. It can realize comprehensive testing of a certain weapon equipment, which is in line with the development direction of modularization, generalization, intelligence and standardization of testing equipment. The system was applied and verified through experiments, and good results were achieved, providing a practical method for the technical support of weapon equipment.