acr1552u

Python library for the ACS ACR1552U NFC reader/writer. Communicates directly over USB via raw CCID escape commands — no PC/SC daemon or middleware required.

Features

• Direct USB communication via libusb1 (no pcscd)
• Full coverage of the vendor escape command set (reference manual section 6)
• RF control, PICC polling, card type detection
• Card emulation: NFC Forum Type 2 Tag and FeliCa
• Discovery mode
• LED (mono and RGB), buzzer, UI behaviour
• HID keyboard output configuration (output format, UID delimiters, keyboard language)
• Type-annotated API; enums for all command parameters and return values

Requirements

• Python 3.11+
• libusb1 (pip install libusb1)
• USB access to the device at 072F:2308

USB permissions (Linux)

Either run as root, or add a udev rule:

SUBSYSTEM=="usb", ATTRS{idVendor}=="072f", ATTRS{idProduct}=="2308", TAG+="uaccess"

Save to /etc/udev/rules.d/99-acr1552u.rules and run udevadm control --reload-rules && udevadm trigger.

Installation

pip install acr1552u

Or with uv:

uv add acr1552u

Quickstart

from acr1552u import ACR1552U, PICCStatus

with ACR1552U() as reader:
    print(reader.get_firmware_version())   # e.g. "ACR1552 R FW 5.00.01"

    status = reader.get_picc_status()
    if status == PICCStatus.PICC_READY:
        t = reader.read_picc_type()
        print(f"Card present: type={t.picc_type:#04x}")

API Reference

All methods are on ACR1552U. Every parameter that corresponds to a vendor enum accepts either the enum member or a raw int.

PICC / RF

Card Emulation

Before switching to an emulation mode, always call enter_card_emulation_mode(NFCMode.CARD_READ_WRITE) first.

Discovery Mode

from acr1552u import ACR1552U, DiscoveryMode

with ACR1552U() as reader:
    reader.enter_discovery_mode(DiscoveryMode.CARD_READER)

LED and Buzzer

from acr1552u import ACR1552U

with ACR1552U() as reader:
    # RGB LED (ACR1552U-A* variant)
    reader.set_rgb_led(red=0xFF, green=0x00, blue=0x00)

    # Buzzer: single beep (50 ms)
    reader.buzzer_single(duration=5)

    # Buzzer: repeating pattern
    reader.buzzer_repeatable(on_time=5, off_time=5, repeat_count=3)

HID Keyboard Mode

Device Info

Architecture

Three-layer design:

transport.py — CCIDTransport
Speaks raw USB via libusb1. Opens the CCID-class interface, detaches the kernel driver if needed, and sends/receives CCID bulk transfers. The one public method is send_escape(cmd: bytes) -> bytes, which wraps the command in a PC_to_RDR_Escape (0x6B) CCID frame and returns the payload from the RDR_to_PC_Escape (0x83) response with the 10-byte CCID header and 5-byte escape prefix stripped.

commands.py — ACR1552U
High-level driver. Each method maps to one section of the vendor reference manual. ACR1552U accepts an optional pre-built CCIDTransport for testing or advanced use; otherwise it constructs and owns one.

constants.py
IntEnum / IntFlag types for all command parameters and return values.

Hardware Notes

• Confirmed firmware: ACR1552 R FW 5.00.01 (ACR1552U-A* variant with RGB LED)
• get_auto_pps() times out on this firmware — the command is unsupported on the A* variant
• get_led_status() returns 3 bytes (R, G, B) on the A* variant rather than 1
• set_rf_power() causes the reader to reset

Development

# Install dependencies
uv sync

# Type-check
uv run pyright src/

# Interactive use (requires USB access)
uv run python -c "from acr1552u import ACR1552U; r = ACR1552U(); print(r.get_firmware_version()); r.close()"

No automated test suite exists — tests require real hardware.