Hi Dean, On Mon, Jun 27, 2011 at 1:11 PM, Dean Brotzel <[email protected]>wrote:
> This is for Google NFC engineers (Nexus S, PN544 hardware/firmware > stack), hopefully they will see this. Or perhaps there is a better > why to contact said engineers? > > I'm working on a semi passive NFC (ISO14443A) custom sensor tag > (hardware/firmware stack) which I would like to pair with the Nexus S > and future android smart phones. This tag is a much more than your > basic run of the mill passive NFC tag. The tag sports multiple > environmental sensors, large memory and a large command set to name a > few. > > Development has been going smoothly until I started to implement > commands that take longer to process and return. I had anticipated > such issues and was hoping I could use FWT via FWI (frame waiting > time) and the S(WTX) command via WTXM (frame waiting time extension > command) from the ISO 14443-4 protocol. (I have used ISO 14443A > terminology here) I have verified the Nexus S utilizes the above > mechanisms but the accuracy differs from the standard. I have found 2 > issues: > > 1) the FWT provided by the Nexus S is much greater (at least 4X) than > what the standards specifies for a specific FWI > 2) also the frame waiting time extension command doesn't seem to > actually extend the wait time. The Nexus S will respond to a S(WTX) > command but doesn't seem to actually increase the time before a > timeout occurs. > > I'm wondering if these are known issues? Is this question better > suited for NXP or Samsung as I'm not sure how much is done in the > PN544 and who actually wrote the firmware for the PN544 with the Nexus > S. > These are not know issues, I have raised them internally, and with some luck hope to update you if we can reproduce and/or fix them in the future. Cheers, Nick -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
