The Mini Pearl Logger is an inexpensive approach to logging environmental data. It is based on an Arduino Pro Mini in combination with a real time clock and a microSD card reader. Those three modules can be purchased (eBay sellers in Asia) for less than US$5.00 (total, including shipping). Adding the microSD card, batteries, wires, etc. can bring the cost of materials close to US$15.00. [![MiniPearl_20170606-9521ps.jpg](]( Ed Mallon's [Cave Pearl Logger]( uses a similar combination of components, and Ed has done extensive testing to extend the field longevity to more than a year. We are still trying to replicate Ed's results, and have not yet managed to log data for more than a month on a few AAA batteries. [![MiniPearl_20170606-9505.JPG](]( Kits of all the parts needed to solder together a Mini Pearl Logger are [available at the KAPtery]( ## Questions [questions:mini-pearl-logger] ## Activities [activities:mini-pearl-logger]

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