We used about 50 of them on a job for Nike earlier this month, reading from a USB-attached credit card reader from MagTek and sending the data to the server over Wi-Fi and in the streetcar, over Bluetooth LE to a co-located iPad Pro (and from there we used its cellular connection to talk to the server). Each Pi worked alongside an iPad Pro as part of an on-site digital retail experience called SNKRS XPRESS where we replicated Nike&#x27;s &quot;SNKRS&quot; app on the iPad Pro and people bought shoes off the app and picked them up immediately. Four simultaneous locations: Toronto, New York, Chicago, and Santa Monica (i.e. Los Angeles).<p>Other fun tech: Node.js on the Pis, NaCl for all crypto, TypeScript on the server (and Node.js), Stripe for handling payments, GraphQL for query handling for the iOS clients, and we used QR code display and reading to distribute public keys during setup. The Bluetooth LE data transfer code between Node.js and iOS was also a nice bit of work by my friend Erik van der Tier in the Netherlands.<p>[0] (Warning: autoplay.) <a href="http:&#x2F;&#x2F;www.huffingtonpost.ca&#x2F;2016&#x2F;02&#x2F;10&#x2F;nike-snkrs-xpress-toronto_n_9205924.html" rel="nofollow">http:&#x2F;&#x2F;www.huffingtonpost.ca&#x2F;2016&#x2F;02&#x2F;10&#x2F;nike-snkrs-xpress-to...</a><p>[1] <a href="http:&#x2F;&#x2F;hypebeast.com&#x2F;2016&#x2F;2&#x2F;nike-snkrs-xpress-pop-up-nyc" rel="nofollow">http:&#x2F;&#x2F;hypebeast.com&#x2F;2016&#x2F;2&#x2F;nike-snkrs-xpress-pop-up-nyc</a><p>[2] <a href="http:&#x2F;&#x2F;weartesters.com&#x2F;nike-snkr-xpress-experience-recap&#x2F;" rel="nofollow">http:&#x2F;&#x2F;weartesters.com&#x2F;nike-snkr-xpress-experience-recap&#x2F;</a>