In our modern world of technology, it’s easy to take “smart” systems for granted. Everything from movie theater tickets to vending machine snacks can be paid for and tracked via connected systems. While there is no end to the debate about whether any of that is actually necessary, or even beneficial, there is no denying how impressive the technology is in the first place. These system are the culmination of a bewildering ecosystem of technology that would have been unfathomable a few decades ago. To demonstrate that, Simon Prickett built his own transit pass system.
Prickett approached this project as if he was building a real-world mass transit pass system, and he designed it in order to learn about Redis databases. A transit pass system like this needs to be able to handle three tasks: let commuters purchase credits, allow them to use those credits to ride on trains or buses, and track all of that data. All of that needs to be secure, and additional functions, like being able to purchase specific kinds of passes, are also desirable.
To create his system, Prickett used three Raspberry Pis. The first Raspberry Pi is paired with an RFID card reader that can be used to load up a card with credits. The second Raspberry Pi also has an RFID card reader, and is used to actually purchase passes with those credits. The last Raspberry Pi is used to monitor the whole system. Everything, including users and their credits, is tracked through the Redis database. While this is just a learning exercise that Prickett doesn’t intend to use this in the real world, it does seem remarkably well thought out.