I'm trying to get my ACR122 (usb) device to emulate a passive NFC tag, but am having difficulty getting the communication to occur properly. I'm hoping someone can see what I'm doing wrong here and help point me in the correct direction.
The response on this other question ACR122 - Card Emulation pointed to a document at http://code.google.com/p/nfcip-java/source/browse/trunk/nfcip-java/doc/ACR122_PN53x.txt but when we follow this to the letter it doesn't behave as expected.
We're using an Samsung Galaxy S3 Android 4.3 device for testing, and are seeing the below behaviour:
Transmit (TgInitAsTarget)
....'......4V@.. FF 00 00 00 27 D4 8C 00 08 00 12 34 56 40 01 FE
................ A2 A3 A4 A5 A6 A7 C0 C1 C2 C3 C4 C5 C6 C7 FF FF
...wfUD3"... AA 99 88 77 66 55 44 33 22 11 00 00
Receive
..%....7.5<...w. D5 8D 25 1E D4 00 08 37 D9 35 3C BF D5 AE 77 9C
...2Ffm......... 00 00 00 32 46 66 6D 01 01 11 03 02 00 13 04 01
... 96 90 00
Transmit (GetData)
....... FF 00 00 00 02 D4 86
Receive
..).. D5 87 29 90 00
The TgInitAsTarget command appears to be working, returning a mode of 0x25 which we understand means "Active mode, DEP, 424kbps".
But then "GetData" command is immediately failing, returning status code 0x29 "The PN532 configured as target has been released by its initiator".
We've tried altering the TgInitAsTarget command with different modes (instead of the 0x00 "All" mode), trying the following which all still return 0x29 for the following GetData command:
- Mode 0x01 "Passive", resulting in response mode of 0x04 "DEP"
- Mode 0x02 "DEP", resulting in response mode of 0x25 (same as the "All")
- Mode 0x03 "DEP Passive" resulting in response mode of 0x04 "DEP"
It appears in all cases as if the Android is not maintaining the connection, although I am not familiar with the NFC DEP protocols enough to know what I'm doing wrong here. I've read the PN532 chip reference, and it seems to indicate that I'm doing everything correctly.
I've also tried a Windows Phone NFC device, and it encounters the same problem and same error code on GetData.
Any help from anyone who is familiar with NFC would be greatly appreciated.
Dave