R200 RFID Module Python Library

A Python library for interfacing with R200 RFID modules via serial communication.

Features

• Partial R200 Protocol Support: Implements the parts of the R200 RFID module communication protocol
• Object-Oriented Design: Clean, maintainable code with abstract interfaces
• Type Safety: Full type hints for better IDE support and code reliability
• Error Handling: Comprehensive error handling with descriptive messages
• Debug Support: Optional debug output for troubleshooting
• Cross-Platform: Works on Linux, Windows, and macOS
• Sync and Async: Supports both synchronous and asynchronous interfaces

Installation

Install from PyPI

pip install rfid-r200

Development Installation

git clone https://github.com/jredrejo/rfid-r200.git
cd rfid-r200
uv pip install -e .[dev,test]
uv sync --group dev

Quick Start Examples

# Run synchronous example
uv run src/main.py

# Run asynchronous example
uv run src/main_async.py

Quick Start

Synchronous Example

from rfid_r200 import R200
import binascii

# Initialize the RFID module
rfid = R200("/dev/ttyUSB0", 115200, debug=True)  # Linux
# rfid = R200("COM3", 115200, debug=True)  # Windows

try:
    # Read RFID tags
    tags, errors = rfid.read_tags()

    print(f"Found {len(tags)} tags:")
    for i, tag in enumerate(tags):
        epc_hex = binascii.hexlify(bytes(tag.epc)).decode()
        print(f"Tag {i+1}: EPC={epc_hex}, RSSI={tag.rssi}")

finally:
    rfid.close()

Asynchronous Example

from rfid_r200 import AsyncR200
import binascii
import asyncio

async def main():
    # Initialize the RFID module
    rfid = AsyncR200("/dev/ttyUSB0", 115200, debug=True)
    
    try:
        # Read RFID tags
        tags, errors = await rfid.read_tags()
        
        print(f"Found {len(tags)} tags:")
        for i, tag in enumerate(tags):
            epc_hex = binascii.hexlify(bytes(tag.epc)).decode()
            print(f"Tag {i+1}: EPC={epc_hex}, RSSI={tag.rssi}")
    finally:
        await rfid.close()

asyncio.run(main())

Using as Context Manager

from rfid_r200 import R200

# Automatically closes the port when exiting the block
with R200("/dev/ttyUSB0") as rfid:
    tags, errors = rfid.read_tags()
    for tag in tags:
        print(f"Found tag: {tag.epc}")

API Reference

Synchronous Interface (R200)

from rfid_r200 import R200

Asynchronous Interface (AsyncR200)

from rfid_r200 import AsyncR200

R200 / AsyncR200 Constructor

R200(port: str, speed: int = 115200, debug: bool = False, timeout: float = 1.0)

• port: Serial port name (e.g., "/dev/ttyUSB0", "COM3")
• speed: Baud rate (default: 115200)
• debug: Enable debug output (default: False)
• timeout: Serial port timeout in seconds (default: 1.0)

Methods

read_tags() -> List[R200PoolResponse]

Read all RFID tags in range. Returns a list of R200PoolResponse objects.

tags = rfid.read_tags()
for tag in tags:
    print(f"EPC: {binascii.hexlify(bytes(tag.epc)).decode()}")
    print(f"RSSI: {tag.rssi}")

send_command(command: int, parameters: List[int] = None) -> None

Send a raw command to the R200 module.

# Get module info
rfid.send_command(CMD_GET_MODULE_INFO)
responses = rfid.receive()

receive() -> List[R200Response]

Receive responses from the R200 module.

close() -> None

Close the serial port connection.

Data Structures

R200PoolResponse

Contains RFID tag information:

• rssi: int - Signal strength
• pc: int - Protocol Control word
• epc: List[int] - Electronic Product Code
• crc: int - Cyclic Redundancy Check

R200Response

Raw response from the module:

• type: int - Frame type
• command: int - Command code
• checksum: int - Checksum value
• checksum_ok: bool - Checksum validation result
• params: List[int] - Response parameters

Available Commands

The library includes constants for all R200 commands:

• CMD_GET_MODULE_INFO - Get module information
• CMD_SINGLE_POLL_INSTRUCTION - Single tag poll
• CMD_MULTIPLE_POLL_INSTRUCTION - Multiple tag poll
• CMD_READ_LABEL - Read tag data
• CMD_WRITE_LABEL - Write tag data
• CMD_LOCK_LABEL - Lock tag
• CMD_KILL_TAG - Kill tag
• And many more...

Error Handling

The library provides comprehensive error handling:

try:
    tags = rfid.read_tags()
except RuntimeError as e:
    print(f"RFID Error: {e}")
except ValueError as e:
    print(f"Data Error: {e}")

Common error messages:

• "No tags detected" - No RFID tags in range
• "Can't execute command" - Invalid command or parameters
• "Read failed" - Tag read operation failed

Advanced Usage

Custom Command Example

# Send custom command with parameters
rfid.send_command(CMD_SET_TRANSMIT_POWER, [0x1E])  # Set power to 30dBm
responses = rfid.receive()

for resp in responses:
    if resp.checksum_ok:
        print(f"Command executed successfully")
    else:
        print(f"Checksum error")

Working with Multiple Modules

# Handle multiple RFID readers
readers = []
ports = ["/dev/ttyUSB0", "/dev/ttyUSB1"]

for port in ports:
    try:
        reader = R200(port, 115200)
        readers.append(reader)
    except Exception as e:
        print(f"Failed to initialize {port}: {e}")

# Read from all readers
all_tags = []
for reader in readers:
    try:
        tags = reader.read_tags()
        all_tags.extend(tags)
    except Exception as e:
        print(f"Error reading tags: {e}")

# Clean up
for reader in readers:
    reader.close()

Troubleshooting

Common Issues

1. Permission Denied: Ensure your user has permission to access the serial port

   sudo usermod -a -G dialout $USER  # Linux
   

2. Port Not Found: Verify the correct port name

   ls /dev/tty*  # Linux
   

3. No Response: Check connections and baud rate settings

4. Checksum Errors: Enable debug mode to inspect raw communication

   rfid = R200("/dev/ttyUSB0", debug=True)
   

Debug Output

Enable debug mode to see raw serial communication:

Sent: aa00220003220a0add
Buffer: aa01220011001e9f12041e008bb2d1234567890123dd

Development

Setup Development Environment

# Install dependencies with uv
uv pip install -e .[dev,test]
uv sync --group dev

# Install pre-commit hooks
uv tool install pre-commit --with pre-commit-uv
pre-commit install

Development Commands

# Run tests
make test

# Type checking
make type-check

# Code formatting
make format

# Linting
make lint

# All quality checks
make check

# Build package
make build

# Full development cycle
make dev

See Makefile for all available commands.

License

GNU General Public License v3.0