When a company builds the infrastructure of a device, we sometimes destroy that infrastructure and use it to solve complex problems. For example, here’s a question that many hackers have wondered – how do you detect if someone puts mail in your mailbox? Depending on the availability of power and wireless / word connection options, this problem can range from “too simple” to “unreasonable to solve”. [dakhnod] Facttag Project – Pigging back Apple’s AirTag infrastructure has made this problem trivial for most hackers.
The project uses a cheap generic CR2032-powered NRF51822 board to send mailbox status via the FindMy system built for Apple AirTag devices. To detect incoming mail, he uses a simple vibration sensor, which is glued to the flap lid – we imagine that for flap-less mailboxes, an optical sensor or a different type of mechanical sensor could be used instead. Every time someone passes by with a FindMy-friendly iPhone [dakhnod]In her mailbox, she receives an update of her status, including a counter where the sensor has been triggered. [dakhnod] It is estimated that the device can last up to one year on a single battery.
The specific NRF51822 board shown in the picture in the title seems to have sold out online for about $ 7, but there are many different NRF51822 boards available and you will be able to use any one of them. For example, [dakhnod] Sends us a picture of a different sensor designed by him, which is housed in a 3D printed case and attached to a CR2032 battery using copper tape. So far, it’s not uncommon for a friendly hackerspace to have a few suitable boards in a drawer somewhere!
This project builds on the OpenHaystack project, a research effort that we told you about earlier. We’ve seen ESP32 microcontrollers use clones before, but the NRF51822’s low-power features are unbeatable for practical applications.