To address the limitations of current ultra-short wave radio training systems, such as limited equipment availability, high maintenance costs, and a significant gap between simulated and real-world operation experiences, this paper proposes an ultra-short wave radio simulation training system based on STM32 and MAX7349. The system uses STM32 as the central microcontroller to manage buttons, LEDs, display screens, and audio interfaces, providing a user interface that closely mirrors actual radio stations. Through serial communication, it exchanges data with the computer and simulates radio communication over a network. This approach ensures trainees gain realistic operational experience without the risks and costs associated with real equipment, making it ideal for large-scale training while reducing electromagnetic interference and radiation.
Military ultra-short wave radios are essential for close-range communication in naval operations, and personnel must be proficient in their use. However, due to the high cost of military-grade radios, it is impractical to provide one for every trainee. Limited equipment often leads to frequent use during training, increasing the risk of damage. Additionally, multiple devices can cause electromagnetic interference, which is a serious concern. To overcome these challenges, simulation-based training systems have become widely adopted in educational settings, offering a safe, efficient, and cost-effective alternative.
This paper focuses on a specific type of marine ultra-short wave radio and implements a physical simulation using STM32 and MAX7349. The design allows for quick installation and replacement, with the circuit board including various button and LED configurations to support different training scenarios. Communication simulation is conducted through a computer network, enabling the replication of ultra-short wave communication environments, service simulations, complex electromagnetic conditions, and the development of customized training scenarios. It also supports real-time monitoring of the training process and evaluation of its effectiveness.
1. System Overall Design
The simulation training system consists of a hardware simulator, student computers, a monitoring computer, and network infrastructure, as shown in Figure 1.
The hardware simulator replicates the appearance and user interface of an actual ultra-short wave radio. It uses the STM32F407 as the core processor, incorporating modules for USB-to-serial communication, audio input/output, display, and a keyboard with LEDs. The USB-to-serial module facilitates interaction between the hardware simulator and the student computer, allowing real-time data exchange and communication simulation.
The student computer connects to the hardware simulator via a USB cable and accesses the network through an Ethernet cable, enabling communication between simulators and coordination with the monitoring computer.
The monitoring computer also connects to the network via Ethernet to oversee all student computers and hardware simulators, ensuring effective control and supervision throughout the training session.
2. Hardware Simulator Circuit Design
2.1 STM32F407 Introduction
Based on the ARM Cortex-M core, the STM32 series of microcontrollers are designed for embedded applications, offering high performance, low cost, and low power consumption. They are widely used in industrial control, data acquisition, and network communication. The STM32F407, selected for the hardware simulator, features a 32-bit ARM Cortex-M4 core running at up to 168 MHz, 192 KB SRAM, 1 MB Flash memory, two full-duplex SPI ports, three I2C interfaces, six serial ports, one FSMC interface, and up to 112 general-purpose I/O pins.
2.2 USB-to-Serial Module Circuit Design
The microcontroller communicates with the student computer via serial communication. Since most modern computers no longer have built-in serial ports, a USB-to-serial conversion is used. The CH340G chip from Nanjing Yuheng is selected for this purpose, as shown in Figure 2. The RX and TX lines of the microcontroller's USART1 are connected to the RX and TX lines of the CH340G. The USB D+ and D- signals of the CH340G are connected to the computer via a USB port, enabling serial communication between the microcontroller and the student computer through a USB connection. In the diagram, Q1 and Q2 form the serial download circuit, allowing one-click software updates via the serial port.
2.3 Audio Input and Output Module
The audio input and output module uses the Wolfson WM8978 as the audio processing chip and the TI LM4990 as the speaker driver. The WM8978 offers advanced digital signal processing, integrated microphone support, and audio data transmission via I2S. It is configured through the I2C interface. The LM4990 is a 2 W audio amplifier that requires minimal external components, eliminating the need for output coupling or bootstrap capacitors, and includes a standby mode to reduce power consumption when not in use.
2.4 Display Module
The display uses a 128×128 dot matrix LCD module with the T6963C controller, connected to the STM32’s FSMC bus. Since the FSMC operates at +3.3 V and the display module requires +5.0 V, a voltage conversion chip is necessary. The SN74LVC4245 from Texas Instruments is used to convert the bus voltage, supporting bidirectional 8-channel voltage conversion.
2.5 Keyboard, Knob, and LED
Tape Wrapping Machine,Wire Wrapping Machine,Box Wrapping Machine,Bottle Wrapping Machine
Kunshan Bolun Automation Equipment Co., Ltd , https://www.bolunmachinery.com