node-nfc-nci

node-nfc-nci

depedencies

cmake

sudo apt install -y cmake automake autoconf libtool pkg-config

linux_libnfc-nci - https://github.com/NXPNFCLinux/linux_libnfc-nci

git clone https://github.com/NXPNFCLinux/linux_libnfc-nci.git

./bootstrap

./configure --enable-i2c

make

sudo make install

It installs the libnfc-nci-linux library to /usr/local/lib target directory. This path must be added to LD_LIBRARY_PATH environment variable for proper reference to the library during linking/execution of application.

setup

npm install node-nfc-nci

https://www.npmjs.com/package/node-nfc-nci

documentation

include const nci = require("node-nfc-nci");

module exports nci interface object with single method listen

listen(callback<function>) - will attempt to initialize the device via the linux_libnfc-nci library on a new thread and immediately call the callback with a context object.

context - context is an event emitter and interface to setting tag write for the next tag to arrive.

events

error - message<string> - emits on any error, even for errors when attempting to initialize the device. arrived - tag<object> - emits on NFC tag arrival departed -tag<object> - emits on NFC tag departure. Provide a copy of the original arrived tag. If NDEF data has been updated during the tag's presence it will not be reflected in departure. written - tag<object>, previous<object> - emits on successful tag NDEF write. Provides updated tag and a copy of the original arrived tag prior to update.

tag object

example

{
  "technology": {
    "code": 9,
    "name": "Type A - Mifare Ul",
    "type": "MIFARE_UL"
  },
  "uid": {
    "id": "04:e1:5f:d2:9c:39:80",
    "type": "NFCID1",
    "length": 7
  },
  "ndef": {
    "size": 868,
    "length": 18,
    "read": 11,
    "writeable": true,
    "type": "Text",
    "content": "hello world"
  }
}

tag write

via context

context.setNextWrite(type<string>, content<string>) - set data to write for next tag arrival, this will attempt to indiscriminately write the next tag that arrives. context.clearNextWrite() - clears the pending next write. context.hasNextWrite()<bool> - flag to check if there is a next write pending. context.immediateWrite(type<string>, content<string>) - attempts to immediately write to the device that is present. However, tag arrived event provides a tag.write function which is an alias of immediateWrite but likely more practical because immediateWrite depends on a device being present.

via tag

tag.write(type<string>, content<string>) - attempt immediate write to which ever tag is present. This write does not guarantee it will write only to the particular tag tag describes, as it's only a convenience alias to context.immediateWrite

Acceptable types

• Text - writes en lang text to the NDEF content

example

const nci = require("node-nfc-nci");

nci.listen(context => {
    context.on("error", msg => console.log(msg));

    context.on("arrived", tag => {
        console.log(`ARRIVED: ${JSON.stringify(tag)}`);

        if (!context.hasNextWrite()) {
            if (tag.uid.id === "04:e1:5f:d2:9c:39:80") {
                tag.write("Text", "hello world");
            }
        }
    });

    context.on("written", (tag, previous) => {
        console.log(`PREVIOUS: ${JSON.stringify(previous)}`);
        console.log(`UPDATED: ${JSON.stringify(tag)}`);
    });

    context.on("departed", tag => {
        console.log(`DEPARTED: ${JSON.stringify(tag)}`);

        if (tag.ndef.content !== "foobar") {
            context.setNextWrite("Text", "foobar"); // will attempt write on any next tag
        }
    });
});