NICERF Launches SA828Pro Walkie-Talkie Module: Integrated Audio Amplifier and Type-C Configuration Interface

In the development of voice communication systems, the design and debugging of RF and peripheral audio circuits usually occupy a significant amount of research and development time. To address this, NICERF has launched the SA828Pro walkie-talkie module. This product is essentially a demo board-level application solution based on the SA818Pro core module, integrated with necessary peripheral circuits. It retains core functions such as 1.6W transmission power, cross-frequency transmission and reception, dual-mode voice and data transmission, and sub-audio. By integrating peripheral circuits on board, it greatly simplifies the hardware design process of terminal products and can be directly used as the motherboard of a small walkie-talkie.

Hardware Architecture and Integration: A Comparison Between SA828Pro and SA818Pro

The SA818Pro is a Surface Mount Device (SMD) core walkie-talkie module that requires developers to design peripheral circuits such as audio amplifiers, power management, and communication interfaces themselves. In contrast, the SA828Pro is a directly deployable board-level solution that integrates the SA818Pro and related peripheral circuits onto a single PCBA, featuring the following technical characteristics:

1. Highly Integrated Peripheral Circuits

• On-board Audio Amplifier: Internally integrated audio power amplifier, supporting up to 2W audio output, which can directly drive an 8Ω speaker. Developers only need to connect an external power supply, speaker, and volume potentiometer to form a complete intercom terminal.
• On-board Type-C Interface: Integrated USB to serial circuit, providing a standard Type-C interface. It eliminates the need for an additional TTL adapter board and can be directly connected to PC configuration software for RF parameter programming.

2. Pure Hardware Logic Control for Frequency Selection

The SA818Pro mainly relies on external MCUs sending AT commands for frequency switching and status control, making it suitable as a system slave device. The SA828Pro is optimized for independent operation scenarios:

• Preset Channels: Supports pre-writing 16 sets of independent transmission/reception frequencies and sub-audio parameters via PC software.
• 8421 DIP Switch Frequency Selection: The module exposes 4 hardware control pins (Pin 4/5/6/7, corresponding to 8421 BCD encoding). Through external DIP switches or simple level combinations, it can switch between the 16 preset channels without real-time MCU involvement.

3. Dedicated Peripheral Control Interfaces

To facilitate overall assembly, the SA828Pro provides direct connection pins:

• Volume Control (VOL): Supports external 50kΩ~100kΩ potentiometers for hardware volume adjustment.
• Received Carrier Indication (SPKEN): Default low level, outputs high level when a valid signal is received, which can directly drive LED indicators or serve as an external wake-up signal.
• Voice Operated Exchange Enable (VOXEN): Reserved VOX function pin, current firmware defaults to outputting high level, reserving a hardware interface for future functional iterations.

RF Performance and Communication Parameters

The SA828Pro inherits the mature RF and baseband architecture of the SA818Pro, suitable for continuous voice communication scenarios, with the following main technical specifications:

• Concurrent Dual-Mode Voice and Data: Supports standard analog voice intercom while possessing lightweight data transmission and reception capabilities. The maximum single payload is 19 bytes, suitable for concurrent transmission of GPS coordinates, device status feedback, or short control commands.
• Cross-Frequency Repeater Support: Transmission and reception frequencies can be configured independently, suitable for cross-frequency repeater communication modes, helping to reduce co-channel interference and enhance frequency configuration flexibility.
• RF Transmission and Reception Specifications: Under a typical 4.0V power supply, the maximum transmission power can reach 32 dBm (approx. 1.6W); reception sensitivity is -124 dBm. In an open Line-of-Sight (LOS) environment, the typical communication distance is about 4–5 kilometers (depending on the antenna, installation height, and site environment).
• Frequency Stability: Built-in 1 ppm industrial-grade Temperature Compensated Crystal Oscillator (TCXO), ensuring frequency deviation complies with communication standards across a wide temperature range of -30℃ to +70℃.

Engineering Value and Applicable Scenarios

The core value of the SA828Pro lies in shortening the hardware development cycle of intercom terminals. By modularizing the core RF module and peripheral circuits, it reduces the development workload for RF and audio peripheral circuits.

• Rapid Prototyping of Intercom Terminals: No need to write MCU driver code; simply pair it with a casing, battery, speaker, and microphone to complete the overall development of a small walkie-talkie, suitable for small-batch rapid delivery projects.
• Broadcasting and Intercom Systems: With its on-board 2W amplifier, it can be directly applied to wall-mounted voice terminals in security monitoring and building intercom systems.
• Customized Special Equipment: Suitable for special equipment with limited space but requiring independent communication capabilities, such as helmet communication and mining intercoms. The on-board Type-C interface simplifies the process of production line batch programming and later maintenance.

Summary: For system-level applications pursuing extreme compactness and deep customization, the SA818Pro SMD module remains the first choice. However, for projects with tight development cycles that need to quickly implement intercom functions or verify concept prototypes, the SA828Pro module, based on a Demo board format, provides a board-level implementation solution more suited for rapid integration and prototype verification.