FP2 backcover NFC with PN533

[tko]

Hi,

NFC cover will be the deciding factor on whether I’ll hold on to my FP2. I love many features of it, but the lack of NFC will eventually drive me away. I seriously hate that my employer-provided-POS-samsung works with the (NFC-based) public transportation of my home town, and my FP2 doesn’t. Some NFC solutions have been proposed here on the forum, but their goals seem rather over-the-top for my purposes. I just need NFC.

Since my time is rather limited at the moment, I thought I’d better ask here first for any apparent pitfalls or prior knowledge. Do you know about possible troubles I’ll run into if I try to interface NXP’s NFC controller PN533 [1] to FP2 back port (PN533 has a USB interface)? Would I need to create drivers for PN533? The drivers might already be present in the android kernel [2] (I’m not a kernel-developer), and adafruit has neat NFC schematics for the sister-chip (PN532) that may prove useful [3].

[1] http://www.nxp.com/documents/short_data_sheet/PN533_SDS.pdf
[2] https://android.googlesource.com/kernel/common.git/+/android-3.4/drivers/nfc/pn533.c
[3] https://learn.adafruit.com/adafruit-pn532-rfid-nfc/downloads

[anon9505190]

Hello,

Because an external NFC device needs usb driver you maybe look at the wrong place with your [2] . Android kernel source tree gives you at drivers/usb only very limited support to external devices. A free usb driver for NXP usb devices I couldnot find. I will work later on the same issue and have my arduino shield from Seeed Studios ready for this. However I am still working on a second battery enhancement as you may see on this forum. I guess that NFC@FP2 will need this anyway.

My research on the same issue to enhance FP2 with NFC lead me to Thomas Skjolberg

skjolber/external-nfc-api

Skjolbergs Apps are alread commercially working for several external usb NFC devices based on ACR NFC-Readers and MIFARE tags:

play.google.com

ACR 1281 USB NFC Reader Utils

Thomas Rorvik Skjolberg

Utility app for the ACR 1281 NFC Reader. Reads and/or sets various reader settings: - Firmware - Tag polling configuration - LEDs and buzzer behaviourConnect the reader via an On-The-Go USB Cable (OTG-USB).The app was built using External NFC Reader Service app, see https://github.com/skjolber/external-nfc-api/tree/developGet in touch if you require professional help with use of ACR readers on Android, or if you have feature requests.Keywords: ACR 1281 C1 NFC USB ACSUtility app voor de ACR 1281 ...

Free

The development tools are free for own API clients

play.google.com

External NFC Reader Service

Thomas Rorvik Skjolberg

External NFC Reader Service. Makes using external NFC readers as easy as native Android NFC. This service app should speed up your development considerably, saving weeks or even months of time and effort.Supported NFC Readers from ACS: - ACR 122U - ACR 1222L - ACR 1251U - ACR 1252U - ACR 1281U - ACR 1283L - ACR 1255U-J1 (No bluetooth support, yet)Some additonal readers might work, but then without proper reader controls (adjusting the LEDs and so on).Note to non-developers: It is pretty close, ...

€ 12,99

play.google.com

MIFARE DESFire EV1 NFC Tool

Thomas Rorvik Skjolberg

Access content of MIFARE® DESFire® EV1 cards. Define your own keys to access encrypted content. Supports AES, (3)DES and 3K3DES encryption schemes.Please provide feature requests if you are interested in the app - the features are read-only for now.Permissions (in addition to NFC) explained:WRITE_EXTERNAL_STORAGE - for writing standard, backup or record file contentsMIFARE DESFire are trademarks of NXP B.V.Toegang tot de inhoud van MIFARE® DESFire® EV1 kaarten. Bepaal uw eigen sleutels om toegan...

Free

There is another approach without external USB : adding NFC internally to any kind of bus structure (I2c) of android:
http://open-nfc.org/wp/editions/android/
Because FP Open OS is compile-ready it maybe - I am not sure - a possible way to get it at work later.

[Marco_P]

Don’t know if it counts, but in the Netherlands are telecom providers who give us a SIM with a NFC chip integrated. Place the sim in your phone and you have also NFC available.

KPN is one of them for sure and I thought Vodafone also.

Not tried/tested with the FP2 by me.

[anon9505190]

Thanks to your advice , but I am not sure if that works for every smartphone without having already a NFC antenna ?
After reading about this gadget I always found dependencies about NFC antennas required for those chips in SD or SIM cards. Has FP2 this NFC antenna ? I am not sure that without any NFC in FP2 just an antenna for NFC is enabled ?
No, I don’t think so . However I am not sure .

[Elipsus]

There is no NFC antenna in the Fairphone (and i miss it :()
The NFC chip on Sim-card is only to enable NFC payment via your service provider, but it need a NFC antenna on the phone to work.

I truly hope that in the near futur, somone (or FP) will make a back cover with an integrated NFC antenna, i would be the first buyer !

Random thoughts: the battery is using a 4 pin connection to the phone, 2 are used for the power, the other two are for the information return (like temperature), as its not a “standard” thermistor, that would require only one pin, it’s most probably an I2C bus, wich is a parallel bus. (so : easy expansion)
Samsung, for example , integrate the NFC chip+ antenna directly on the battery, and uses an I2C bus for it, so, technically, i would be possible to have, in the future, an NFC enabled battery, but it’s very highly hypothetic

[anon9505190]

it’s most probably an I2C bus, wich is a parallel bus.

Nope, sorry it is Batt-ID pin. [quote=“Elipsus, post:5, topic:20973”]
wich is a parallel bus. (so : easy expansion)
[/quote]

I worked on it on a different topic e.g. “case extension available” (as 3D printout)
Again, no, it is not an easy expansion with nothing on FP2. OK anything goes with USB host, but it needs more battery . In fact I think it is a myth to expand FP2 anyways.