External NFC Service (native style) for Android

Library for interaction with ACS NFC readers over USB; external NFC support Android devices.


As this project very much simplifies implementation for use-cases requiring external NFC readers, it saves a lot of development time (2-8 weeks depending on use-case and previous knowledge).

Bugs, feature suggestions and help requests can be filed with the issue-tracker. DO NOT send me emails unless you're prepared to pay for my time.


Apache 2.0


This repository contains source code for

There is also a Host Card Emulation client app for use with the Basic client app as well as Android-to-Android communication.

External NFC reader API

The API defines

Supported readers

Currently the ACS readers

are supported and must be connected to your Android device via an On-The-Go (OTG) USB cable.

Additional ACR readers might work depending on their command set, however custom reader commands will (like LED, beep etc) will not be available.

Supported tag technology

The following tags are supported by the service

The readers can for the most part can be enabled for all tag types at the same time, including Host Card Emulation.

Please note:

Configuration options

Reader connection

Note that not all Android devices actually have an USB hub, in which case no USB devices work.

Does the ACR reader not light up when connected to your device, even after the service asks for USB permissions? The ACR reader shuts down if there is not enough battery, so try charging your battery more, or connect external power.

If you are using external power, be aware that the connection order (device, reader, power) might be important. Known symptom:

Tag detection

There is quite a few types of tags out there, and if your tag type is not recognized, please let me know. If the tag does not register at all, make sure that auto polling is configured, and that the right protocols are enabled. Use the below utility apps for tweaking your reader settings.

Reader setting utility apps

You might be interested in

for configuration of your reader. Approximately the same configuration options are available using this API.

See also

This project contains adapted code from