Setup guides
The practical questions that come before the course: getting a reader working, sending a first APDU to a payment card, and what to do with a capture once you have one. Free, and always will be.
Getting a first read
How do I send my very first APDU to a payment card?
Find the card, then ask it for its payment directory. Two steps, and the second one is the same on every EMV card on earth.
Why can't my reader capture a transaction at a real terminal?
Because a reader generates the field. To hear two other parties talk you must not be one of them, and that is a different mode with different hardware.
Hardware
Which device should I buy to work on payment cards?
It depends on whether you need to talk to a card, watch two other things talk, or sit between them. Most people buy the wrong one first.
My PN532 board is wired up and completely silent
Check the bus selector before the wiring. The board must be told whether it is speaking UART, I²C or SPI, and the default is often not the one you assumed.
Drivers and software
Working safely
How do I choose a password that is actually strong?
Make it long and make it random. Everything else — the capital, the digit, the exclamation mark — is worth far less than one more word.
I captured a transaction from a real card. What do I do with it?
Treat it as cardholder data from the moment it exists, and sanitise before you store it — not before you publish it.
7 guides. They answer the questions people actually arrive with — if yours is not here, it is probably worth adding.