tap-in prototype (with no-dial phone and rfid)

Some lessons learned:
  • make sure you buy blank cards that match your reader. we picked a reader that worked with bus/metro cards and student id cards for door access. (specifically a Mifare IC card reader 13.56 mhz, see amazon link.) It seems that there are primarily two frequencies: 13mhz is what we use.
  • Want to match a particular transit system card? see this wikipedia page on Mifare cards (e.g., Washington DC uses "MIFARE Plus X")
  • Since there were so many standards, I also just looked to make sure the card could match the standard of my reader ("ISO14443A"). The ones that worked were listed as "50pcs RFID Proximity Control Entry Access 13.56Mhz ISO14443A MF S50 ISO IC Card" on ebay ($18.95 with free shipping, per July 2016)
no-dial red phone (can fit an RFID reader underneath)