HP Spectre Envy and the case of hidden NFC

HP Spectre is arguably the first mass-produced laptop with an integrated NFC reader. While Lenova has reportedly experimented with NFC in a small number of their venerable business laptops, HP delivered the first off-the-shelf device for sale in the US. What follows are observations from experiments with this capability. These can be best summed up as a collection of surprises.

The first surprise is the extent that NFC is downplayed by the marketing literature. The product pages dedicated to the Spectre and its close cousin Spectre XT are not shy about their accolades, such as the CES 2012 award. But there is nary a mention of NFC anywhere on the page, not even in the product specifications. Main search results for NFC on the HP website refer to as-yet-unreleased Windows 8 tablet called Envy X2. Only a single support link on the right alludes to troubleshooting NFC for the Spectre. In fact there is more excitement about and references to NFC on external blog posts from January covering the product announcement and later full reviews. (HP has since also announced an all-in-one desktop with integrated NFC called Spectre One, that has been controversial for its iMac-inspired all metal styling.)

The next surprise is that exterior design does not advertise NFC either. It’s not that logos have been banished entirely in the service of some minimalist aesthetic:  there is a back-lit red icon for Beats audio, in case you missed that, and even a self-referential track pad symbol on the track pad. But there is no NFC icon to guide users towards the antenna location– under the palm-rest, immediately to the left of the trackpad as it turns out. This could be a usability problem. The “N” in NFC stands for “near” and for good reason:  tags, cards and smart-phones have to be placed right above the antenna in order to exchange data using that technology. That’s a challenge when users do not know where the antenna is located.

Incidentally the placement of said antenna faces a very strict constraint from physics: metal interferes with the ability to modulate the RF field. That leaves the palm-rest (which is a layer of Gorilla glass on top of plastic) and the capacitive surface of the trackpad as two logical options. The choice for the Spectre makes eminent sense for ergonomic reasons, compared to forcing the trackpad to do double-duty as NFC antenna. User may want to leave a tag/card/phone on top of the reader while continuing to interact with the machine. The same principle also argues against using the keyboard, screen or any other part of the user interface. One can imagine this is going to be challenging for Apple, as Macbooks have a signature all-metal exterior shell, with only two areas are exposed: the Apple logo on outside of the top lid, and the trackpad. Meanwhile MSFT threw in the towel when faced with the same problem, hinting they dropped NFC from the all-magnesium Surface tablet because of metal inteference.

Back to the Spectre: under the hood is the NFC controller PN533, produced by NXP Semiconductors. For comparison the majority of Android devices feature the PN544 from the same family, coupled to an embedded secure element also produced by NXP. Main difference here is there is no hardware SE inside the laptop. (Nor is there another viable candidate such as TPM or SIM card slot in the laptop that could be substituted using single-wire-protocol. )

In terms of the three NFC modes, the existing driver only exposes support for peer-to-peer mode. This is the second surprise, as it constrains usage in crucial ways.



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