13.56Mhz RC522 RFID Card Reader Module

The HW-126 is a common hardware revision or model designation for the popular RC522 RFID Reader/Writer Module. It is a highly integrated communication device that operates on the 13.56 MHz frequency, primarily used for contactless data exchange in DIY electronics and security projects.

Key Technical Specifications

The HW-126/RC522 module is designed for low-power, compact applications:

• Operating Frequency: 56 MHz.
• Operating Voltage: 3V DC (Note: Connecting it to a 5V pin can destroy the module).
• Current Consumption: 13–26mA (working), <80uA (sleep mode).
• Communication Protocol: SPI (Serial Peripheral Interface).
• Supported Card Types: Mifare1 S50, Mifare1 S70, Mifare UltraLight, Mifare Pro, and Mifare Desfire.
• Read Range: Approximately 0–60mm, depending on the tag and environment.

Standard Pinout for Integration

When connecting the HW-126 to microcontrollers like the Arduino Uno, the following pin mapping is typically used:

• VCC: 3V (Must be 3.3V)
• RST: Reset (often digital pin 9)
• GND: Ground
• MISO: Master In Slave Out (digital pin 12)
• MOSI: Master Out Slave In (digital pin 11)
• SCK: Serial Clock (digital pin 13)
• SDA (SS): Slave Select (digital pin 10)

Common Applications

The HW-126 is frequently found in “Arduino Security Starter Kits” and is used for:

• Access Control: Unlocking digital door locks using authorized RFID tags.
• Attendance Systems: Tracking entries and exits in a workplace or school.
• Inventory Management: Identifying and tracking labeled items.
• Smart Meters: Used in portable hand-held devices for data collection