RFID Dual Frequency 13.56MHz 125KHz Read/Write Module UART T5577
RFID Dual Frequency 13.56MHz 125KHz Read/Write Module UART T5577
LIHTNE T7941W Dual-Frequency RFID Read/Write Module
The LIHTNE T7941W is a compact, high-performance dual-frequency RFID read/write module that handles both 13.56 MHz (IC) and 125 KHz (ID) card protocols in a single unit. Whether you're building an access control system, an automation project, or an embedded IoT solution, this versatile module communicates via a simple UART serial interface and supports a wide range of card standards including ISO/IEC 14443A, NTAG, Mifare S50/S70, and T5577 rewritable cards.
Key Features
- Dual-Frequency Operation: Reads and writes both 13.56 MHz and 125 KHz cards in one module — no need for separate readers.
- Wide Protocol Support: Compatible with ISO/IEC 14443 A/MF, NTAG, S20, S50, S70, F1108, EM4100 (read-only), and T5577 (read & write).
- Simple UART Interface: Easy integration with microcontrollers (Arduino, Raspberry Pi, STM32, etc.) via standard TX/RX pins.
- Compact Form Factor: Measures just 47 mm × 26 mm × 5 mm — ideal for space-constrained enclosures.
- Robust Operating Temperature: Reliable performance from -25°C to 85°C for demanding environments.
- Read Range: MF1 cards >3 cm; EM cards >5 cm.
- Low Power Consumption: Operates at DC 5V with only 50 mA current draw.
Technical Specifications
| Model | T7941W |
| Operating Voltage | DC 5V |
| Current Consumption | 50 mA |
| Frequencies | 13.56 MHz & 125 KHz |
| Read Range | MF1 >3 cm; EM >5 cm |
| Interface | UART (TX / RX) |
| Dimensions | 47 mm × 26 mm × 5 mm |
| Operating Temperature | -25°C to 85°C |
| Country of Origin | Made in China |
Pin Connection Guide
- 5V — DC 5V power supply (linear power supply recommended for best performance)
- RX — UART receive pin
- TX — UART transmit pin
- GND — Power supply ground
- IO — Configurable I/O pin
Supported UART Command Set
The module uses a structured binary protocol with a 2-byte header, address byte, command byte, data length, data payload, and XOR checksum for reliable communication.
-
0x10— Read UID number -
0x11— Write UID number (4 bytes, default password) -
0x12— Read specified sector -
0x13— Write specified sector -
0x14— Modify Group A or Group B password -
0x15— Read ID number -
0x16— Write T5577 card data -
0x17— Read all sector data (Mifare 1K card)
Send header: 0xAB 0xBA | Return header: 0xCD 0xDC | Success: 0x81 | Failure: 0x80
What's in the Box
- 1× RFID Dual-Frequency Read/Write Module (T7941W)
Learn More About RFID Technology
For a deeper understanding of RFID standards and frequency bands, visit the NIST Guidelines for Securing RFID Systems.
Frequently Asked Questions
Q: What is the difference between 13.56 MHz and 125 KHz RFID, and does this module support both?
A: Yes — this dual-frequency RFID module supports both 13.56 MHz (high-frequency, used for Mifare/ISO14443A cards like S50, S70, NTAG) and 125 KHz (low-frequency, used for EM4100 and T5577 cards). The 13.56 MHz band offers higher data transfer speeds and better security features, while 125 KHz cards are common in older access control systems. This module handles both in a single compact unit.
Q: How do I connect this RFID module to an Arduino or Raspberry Pi?
A: Connect the module's 5V pin to your board's 5V supply, GND to ground, TX to the microcontroller's RX pin, and RX to the microcontroller's TX pin. The module communicates via standard UART serial protocol, making it straightforward to integrate with Arduino, Raspberry Pi, ESP32, STM32, and similar platforms using the documented binary command set.
Q: Can I rewrite T5577 cards with this module?
A: Yes. The T7941W specifically supports T5577 card writing via UART command 0x16, allowing you to clone or overwrite 125 KHz card data onto rewritable T5577 blanks — a common requirement in access control development and testing.
Q: What is the maximum read range for this RFID module?
A: The read range is approximately 3 cm for Mifare (MF1) cards and 5 cm for EM-type cards. Using a linear (regulated) power supply instead of a switching supply can help improve overall signal stability and detection consistency.
Q: Is this module suitable for industrial environments?
A: The T7941W is rated for an operating temperature range of -25°C to 85°C, making it suitable for a wide range of environments including light industrial, outdoor enclosures, and embedded systems where temperature variation is a concern.