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. I realize most NFC developers will never run into these issues but I'm trying to push the use of smart phones into a unique area. Thanks for your time, any help is appreciated Dean -- 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
