RUGGED DATA LOGGER
CAN YOUR DATA LOGGER DO THIS?
that came down from 50,000 feet sans parachute. In all of those cases, the equipment that was put in place to record data didn’t survive. Go figure. Frustrated with this, I began working on my own rugged data logger—something that could survive fire, water, and smashing and that would, ideally, be self-contained The details continue to evolve, but the general concept is a circuit that stores data in flash memory, has no moving parts and no mechanical connections to fail, and is potted in epoxy. The potting epoxy is a key element of this design, keeping everything in one piece and protecting the circuit from its environment. In this version I included a Li-ion rechargeable battery in the epoxy puck, making the logger completely selfcontained. A set of headers embedded in the epoxy —recessed and protected, for the most part, but still accessible—allow me to connect and download the recorded data, charge the battery, and reprogram the ATmega chip inside as needed. The ATmega328 I used has the Arduino bootloader burned onto it so I can easily reprogram it in-circuit from within the Arduino IDE To save space and keep the board simple, I decided against including USB support directly in the data logger. Instead, I connect the logger to the computer with a FTDI (USB to Serial) cable. If this logger does eventually meet its match, at least I won’t have to replace the FTDI chip when I build the next one. The data being logged can come from something like an accelerometer or a GPS, also potted in the epoxy,
I’ll be the first to admit that things around me sometimes get destroyed. There were the gas-powered bumper cars whose engines broke off of the mounts. Then there was the crushed SD card we recovered from a camera that had been 12,000 feet underwater when the housing failed. And of course there was that rocket