Android Question use the acs reader NFC API

[dannythevii]

hi to all

i want to read/write a nfc ntag or mifare ultralight with an acs external reader.

this code work well, but i don't understant how to read/write cards

someone can help me with an axample or a little demo ?

please

tanks

 

[Erel]

I'm not sure that this library supports writing. You can check the documentation: http://www.acs.com.hk/download-driver-unified/5102/ACS-EVK-Android-113-A.zip

In the code written by @JTmartins the status_event sub should be raised when a card is read.

 

[dannythevii]

mr. Erel,
initialy tanks.
i already do this, i used the code of mr. JTMartins, but it not read/write the fields of card
in this moment i try to understand the acs evk but for me is very hard

I had seen that many posts on forum works correctly on internal nfc reader op bluethoot , not on usb; on various post like https://www.b4x.com/android/forum/threads/nfc-tagwriter-and-ibeacon-libraries-for-free.42137/

when the procedure comes to .EnableForegroundDispatch there is an exception if the lector is external usb, nothing if internal.

tanks for all your help

 

[dannythevii]

no one ?

 

[DonManfred]

I'm not sure that this library supports writing

It does Support writing. But only "SmartAccess"-Cards. These Cards have 3 Strings stored. Name, Company and Position.
You are not able to create userdefined NFC-Card-Content with the ACSSMC Lib.
Except if you write new Classes to Write/Read the Content of the Cards presented to the Reader.

I did a recompile of their SmartAccess-App to look at the sources.

There are a few methods to read or write to a specific Card (Mifare, Acos3). But all of them will create/read just the Cards with those 3 Strings.
Name, Company and Position.

Based on the code of these Methods one should be able to create specific mthods for any Kind of Data. I guess. I´m not sure if i would able as i did not understand the code completely

Example (note that is a source based on a decompiled APK)

    public void writeMifareCard() {
        this._receiveDataList = new ArrayList();
        this._commandApduList = new ArrayList();
        this._receiveCount = 0;
        resetAll();
        try {
            this._commandType = COMMAND_TYPE.UPDATE_BLOCK;
            byte[] dataToWrite = new byte[16];
            System.arraycopy(Helper.stringToByteArray("SMARTACCESSAPP", 14), 0, dataToWrite, 0, 14);
            this._mifare.updateBinaryBlock((byte) 4, dataToWrite, (byte) 16);
            this._commandApduList.add(0, this._mifare.get_apdu().getCommand(false));
            dataToWrite = new byte[32];
            System.arraycopy(this._name, 0, dataToWrite, 0, this._name.length);
            this._mifare.updateBinaryBlock((byte) 5, dataToWrite, (byte) 32);
            this._commandApduList.add(1, this._mifare.get_apdu().getCommand(false));
            this._acr1255.authenticate((byte) 8, KEYTYPES.ACR1281_KEYTYPE_A, (byte) 0);
            this._commandApduList.add(2, this._acr1255.get_apdu().getCommand(false));
            dataToWrite = new byte[16];
            System.arraycopy(this._organization, 0, dataToWrite, 0, this._organization.length);
            this._mifare.updateBinaryBlock((byte) 8, dataToWrite, (byte) 16);
            this._commandApduList.add(3, this._mifare.get_apdu().getCommand(false));
            dataToWrite = new byte[16];
            System.arraycopy(this._position, 0, dataToWrite, 0, this._position.length);
            this._mifare.updateBinaryBlock((byte) 9, dataToWrite, (byte) 16);
            this._commandApduList.add(4, this._mifare.get_apdu().getCommand(false));
            startCommandExecution();
        } catch (Exception e) {
        }
    }

The problem is one needs to know how these "APDU"-Commands/Protocol works... Honestly i did not read much in the documentation... just the source

I´ll be probably able to provide a lib which can read/write such Cards (working on it). Not sure if i get success with it.

 

[dannythevii]

Thanks mr. Manfred, very kind and competent.
Also because I did not think to decompile an apk or a library !

I asked to acs help for low level commands, if they answer me... i place it here ! Maybe we can make a universal library.

Now understand why there are so many NFC apps on android ... why if one can do a program like that ... ALL MUST KNOW !!!

But maybe some other friend can help us ... please

Thanks and compliments
Daniele

 

[DonManfred]

Additionally to the ACSSMC lib there is a Lib for the Reader itself (without methods to read/write SmartAccess cards).

This library is able to execute APDU-Commands and to receive the Answer to the call.
So, one have the rigth tools to communicate with the reader and send commands to read/write. But i dont know how the APDU must look like.
I may be able to find out with reverse engeneering the ACS App.

I have a wrap working for my ACR1522-J1. You can find it here

But: I guess we need to have a cmbination of both. The reader and the SMC lib. I´m working on it.

 

[dannythevii]

dear DonManfred

i had seen that library usbserial -> deviceinfo() see all info of reader ... i think is a good start.
your is a great work but only for bluethooth

i think a good idea is also to "sniff" the output of a serial reader (now i search to my friends) so we can see all traffit to/from reader.

but ... if i understant ... you have changed a java library in b4a library ?? great work !!!

regards and tanks for now


p.s. More hard the way ... more sweet the victory !!

 

[dannythevii]

No one?

 

[DonManfred]

No one?

No one WHAT?????

 

[dannythevii]

I'm sorry to have annoyed asking help, but this problem is very important to me.

mr. DonManfred ... thank's for your attempts to help me

best regards