Easily Integrated: All-in-one RFID reader module with integrated microcontroller, analog circuit, and antenna driver requires only an antenna and power supply to function

Flexible Usage: With 2.54mm pitch standard pin headers, the module is compatible with standard pin sockets for easy plug-and-play installation

Automatic Operation: Independently processes RF signals, demodulates and decodes tag data without an external controller

Supports Multiple Transponders: The module is compatible with Atmel/Temic T55xx tags (e.g., T5557, T5567, T5577) and widely-used EM4100/02, TK4100 tags. It also supports both Manchester RF/32 and Manchester RF/64 modulations

Wide Operating Voltage Range: Supports both 3.3V and 5V power supplies

Flexible Communication Interfaces: UART and I2C options for seamless integration. See the SM125-M2-232 for an RS232 interface option

Read Range: Offers a practical read range of 5-10 cm (2-4 inches), with a typical read range of 7.5 cm (approximately 3 inches), varying based on tag type and antenna size

GPIO Control: Non-blocking GPIO control including Buzzer, LED, and Relay support

Customizable Firmware: Upgradeable firmware for tailored applications

Upgrade-able: Integrated bootloader for easy firmware updates and custom firmware development

Wiegnad 26-bit Output: Supports programmable Wiegand 26-bit output format

Second Gen: 125 kHz RFID DIP Module for proximity card applications with RS232 Interface

The SM125-M2-232 is a 28-pin DIP type module, highly integrated RFID reader module for the 125 kHz frequency. It combines a low power ARM® Cortex® microcontroller, analog circuitry, and an antenna driver in a compact package This module is designed to provide OEMs with a reliable, cost-effective solution for embedding RFID functionality into their products, offering ease of integration and robust performance across a wide range of RFID proximity card applications.

The SM125-M2-232 is identical to the SM125-M2 module, but it also includes an ST232 IC (RS232 driver chip) on the bottom side of the module.

As with all second-generation 125 kHz RFID modules, this module can be controlled via UART-RS232/I2C or can autonomously read compatible tags without external intervention. It manages all analog and digital signal processing, preparing tag data for transmission over UART/RS232/I2C/Wiegand interfaces. Furthermore, it can trigger Buzzer/LED/Relay circuits based on configurable parameters.

The SM125-M2-232 succeeds the first-generation SM125-M1-232 module. The M1 utilized Sonmicro's pioneering System-on-Chip (SoC) based RFID IC, the SM125-IC. The SM125-M2-232 embodies years of continuous improvement and proprietary technologies developed by Sonmicro.

It maintains compatibility with the first-generation SM125-M1-232's functionality, communication interface, and command set, making it an ideal successor for existing designs.

Alternative Form Factors

SM125-M2-232 is a 28-pin DIP type module, ideal for applications requiring a through-hole mounting option.

Compatibility and Migration

The SM125-M2-232 is pin-to-pin compatible with the first-generation SM125-M1-232 module, ensuring a seamless transition for existing designs. However, both the SM125-M1-232 and SM125-M2-232 are exclusively offered for existing designs. For new projects, we recommend exploring the SM1250B-MINI (MINI20 package) and SM1251-SMD (SMD20 package) 125 kHz RFID modules. While the SM125-M1-232 and SM125-M2-232 remain available for existing customers, we encourage the adoption of new package type modules for future designs to leverage the latest advancements in manufacturing and availability.

SM1251-SMD

For surface-mount applications, consider the SM1251-SMD module, which offers the same functionality as the SM125-M2 but in a surface-mount form factor, ideal for automated assembly processes.
Note that the SM1251-SMD does not include the RS232 interface.

SM1250B-MINI

For plug-and-play usage, the SM1250-MINI features 2.0 mm pitch low-profile pin headers, making it easy to integrate into your existing designs with compatible sockets on the motherboard. Functionalities are identical to the SM125-M2, with the only difference being the form factor.
Note that the SM1251-SMD does not include the RS232 interface.

Tailored for Proximity Card Applications

The SM125-M2-232 module is designed for compatibility with a variety of transponders, including Atmel/Temic T55xx and the widely used EM4100/02. It supports both Manchester RF/32 and Manchester RF/64 modulations. Engineered for simplicity, it requires only an antenna and a power supply to function effectively. The module automatically demodulates and decodes RF signals, preparing the actual tag data for immediate use.

Compact and Complete

Includes all necessary components for a 125 kHz RFID reader, except the antenna.

Automatic Functionality

Independently performs all necessary signal processing; no external controller required.

Flexible Interfaces

Offers UART/RS232 (up to 115200bps @5V) and I2C (up to 400KHz) communication options.

Customizable Outputs

Features controllable General Purpose Outputs and Inputs, with a programmable Wiegand 26-bit output format.

Firmware Flexibility

The module's firmware is upgradeable to accommodate custom-specific applications, enhancing its adaptability to future needs.

Application-Driven Design

Ideal for embedding into products such as access control systems, the SM125-M2-232 supports a wide array of applications due to its powerful features. It is particularly suited for designers seeking to integrate RFID functionalities without the bulk or complexity of traditional designs.

Advanced Features and Benefits

Power Supply

Unlike the SM125-M2, which can operate with a 3.3V or 5V power supply, the SM125-M2-232 is recommended to use a 5V power supply when working at higher RS232 baud rates.

Future-Proof Design with Integrated Bootloader

The SM125-M2-232 features a built-in bootloader, a valuable tool for keeping your device up to date. This bootloader allows for:

Easy firmware updates

Ensures your device benefits from the latest features and performance improvements.

Custom firmware development:

Enables you to tailor the module's functionality to your specific application needs.

Plug-and-Play Installation

Effortless Setup

The SM125-M2-232 features convenient standard 2.54mm pin headers that allow for simple plug-and-play installation when used with standard pin sockets. This eliminates the need for soldering, saving you time and effort during assembly.

Surface Mount Option Available

If your project requires surface mounting, consider the SM1251-SMD module, a variation designed for automated assembly processes.
Note that the SM1251-SMD does not include the RS232 interface.

Advanced Customization Options

We offer customization services tailored to meet specific project needs, from custom firmware development to complete system design. Whether adjusting form factors, antenna designs, or integration protocols, our goal is to ensure that the SM125-M2-232 not only meets but exceeds your project requirements.

Contact us today to explore how the 125 kHz RFID modules and solutions can enhance your product offerings with its advanced features, reliability, and scalability.