How to Use M5Stack UHF-RFID: Examples, Pinouts, and Specs

The M5Stack UHF-RFID is a compact RFID reader module designed for UHF (Ultra High Frequency) tags, enabling wireless identification and data transfer. This module is compatible with M5Stack systems and features a built-in antenna for efficient scanning. It is ideal for applications requiring long-range RFID reading, such as inventory management, asset tracking, and access control systems.

• Inventory and warehouse management
• Asset tracking and monitoring
• Access control and security systems
• Logistics and supply chain automation
• Smart retail and point-of-sale systems

The M5Stack UHF-RFID module is designed to provide reliable and efficient RFID tag reading. Below are its key technical specifications:

The M5Stack UHF-RFID module connects to M5Stack systems via the Grove port. Below is the pin configuration for the Grove connector:

1. Hardware Setup:

   • Connect the M5Stack UHF-RFID module to the Grove port of an M5Stack Core device.
   • Ensure the module is powered with 5V DC through the Grove connector.

2. Software Setup:

   • Install the required M5Stack libraries in your Arduino IDE.
   • Use the UART interface to communicate with the module.

Below is an example of how to use the M5Stack UHF-RFID module with an Arduino UNO. This code reads RFID tag data and prints it to the serial monitor.

#include <SoftwareSerial.h>

// Define RX and TX pins for SoftwareSerial
#define RX_PIN 10  // Connect to TX pin of UHF-RFID module
#define TX_PIN 11  // Connect to RX pin of UHF-RFID module

// Initialize SoftwareSerial for communication with the RFID module
SoftwareSerial RFID(RX_PIN, TX_PIN);

void setup() {
  Serial.begin(9600);  // Start serial communication with PC
  RFID.begin(115200);  // Start communication with RFID module

  Serial.println("M5Stack UHF-RFID Reader Initialized");
  Serial.println("Waiting for RFID tags...");
}

void loop() {
  if (RFID.available()) {
    // Read data from the RFID module
    String tagData = "";
    while (RFID.available()) {
      char c = RFID.read();
      tagData += c;
    }

    // Print the received tag data to the serial monitor
    Serial.print("RFID Tag Data: ");
    Serial.println(tagData);
  }
}

• Power Supply: Ensure the module is powered with a stable 5V DC supply to avoid communication issues.
• Reading Distance: The reading distance may vary depending on the type and orientation of the RFID tag.
• Interference: Avoid placing the module near metal objects or other RF devices to minimize interference.

1. No Data Received:

   • Ensure the module is properly connected to the Grove port.
   • Verify the UART baud rate is set to 115200 bps in your code.
   • Check the power supply voltage (5V DC) and ensure it is stable.

2. Short Reading Distance:

   • Ensure the RFID tag is within the module's effective range (up to 1 meter).
   • Check for potential interference from nearby metal objects or other RF devices.

3. Module Not Detected:

   • Verify the RX and TX connections between the module and the microcontroller.
   • Ensure the correct pins are defined in the code for UART communication.

Q: Can the M5Stack UHF-RFID module read multiple tags simultaneously?
A: Yes, the module supports anti-collision algorithms, allowing it to read multiple tags within its range.

Q: What is the maximum reading distance of the module?
A: The module can read tags up to 1 meter away, depending on the tag type and environmental conditions.

Q: Is the module compatible with non-M5Stack systems?
A: Yes, the module can be used with other microcontrollers (e.g., Arduino, ESP32) via the UART interface.

Q: How do I change the UART baud rate?
A: The baud rate can be configured by sending specific commands to the module. Refer to the M5Stack UHF-RFID command set documentation for details.

By following this documentation, you can effectively integrate and use the M5Stack UHF-RFID module in your projects.