I regularly back-up my Raspberry Pi storage card because it’s so easy to damage the card with an improper shutdown or some such. I back up to a Mac, and you can read how I do it here. This wasn’t much of a chore in the early days when I was working with 4GB cards, but now I use 16GB Micro SDs and I know of folks who have much, much larger storage capacities thanks to never-cheaper cards. All this means the back-up takes a long time. So I wondered if I could create a gadget to tell me the task was done, allowing me to get on with other jobs in the meantime.
US department store Macy’s recently said it is implementing iPhone-based tracking tech the better to encourage browsing punters to buy. Of course, Macy has chosen to pitch this as an Apple technology – figuring, presumably, iPhone owners are more receptive to inducements delivered through technology and have more cash to splash than Android fans.
But the fact is, the system Apple calls iBeacon simply makes use of features already part of the Bluetooth Low Energy (LE) spec.
This got me thinking: how difficult would it be to build a similar system of my own? Not very hard at all, it turns out. Choose the right kit and it can be quite cheap too. I created my beacon using a £30 Raspberry Pi and a £12 Bluetooth 4.0 USB dongle.
I’m enjoying tinkering with the Raspberry Pi. Alas most of the tutorials and guides available online, of which there are many, focus on hooking the tiny board computer to Windows or Linux machines. Mac-centric guidance is sparse, and I could have used some this week.
The Pi has 26 general purpose IO ports on board, two of which can be used for UART (Universal Asynchronous Receivers/Transmitters) communications. The Pi hooks its UART pins to a login console at boot, and it should be straightforward with a suitable USB-Serial adaptor — I have the TTL-232R-3V3 from FTDI Chip — to view the results of the start-up process on a terminal window in Mac OS X. I bought my cable from Farnell, by the way — it terminates in three female connectors ready to slot onto the Pi’s GPIO pins.