Data loggers can help to record data from a sensor over time -- often over days or weeks, or even months. There are a variety of data loggers available, both commercial and open source. Each entry from a logger -- stored on, for example, a memory card -- may have a timestamp and some data loggers can record location from a GPS as well.
Data loggers can be [paired with specific sensors](/wiki/water-sensors), and an [enclosure](/wiki/sensor-enclosures), as part of a test.
## Design constraints
What are we trying to do that existing commercial data loggers don't do, or don't do well enough? We're looking for designs that optimize:
* low cost (i.e. <$100)
* easy to use
* easy to build or buy
* weatherproof (possibly)
* waterproof (possibly)
* Arduino-compatible (so that they're compatible with the huge [Arduino](http://arduino.cc) ecosystem)
Most of the below options are #arduino based, and all are open source:
Edit the [full spreadsheet here](https://docs.google.com/spreadsheets/d/1zBcLpN4PZIATLh6aDR7mwCoejWryLYYm6cJD38MqT58/edit) (by @cfastie)
We're hoping to collect a set of activities you could do with several different data loggers here, such as an example "field test," so please add help us by adding activities which can be performed with different data loggers:
How do you keep a data logger going in the field? Solar, big batteries, even run an extension cable out? We're developing resources on powering your data-loggers here.
## Power Questions
## Waterproof enclosures
The #riffle project -- and others -- have explored a lot of ways to make cheap waterproof enclosures for data loggers, but where wires and sensors can still stick out. Here are a some notes and prototypes under the tag #data-logger-enclosures. You can also visit the page on [sensor enclosures here](https://publiclab.org/wiki/sensor-enclosures)