Welcome to EnviroDIY, a community for do-it-yourself environmental science and monitoring. EnviroDIY is part of 
Our Arduino datalogger designs have gone through a few improvements since our original models four years ago. This past year we refined the design even more and have come up with our most rugged and reliable system yet.
The datalogger is still based on the Seeeduino Stalker board, which has solar battery charging circuitry, memory card slot, real time clock, and a socket for an XBee radio or cell phone module. A short RF cable and panel-mount jack allow an external antenna to be used. The datalogger is powered by a 2-Ah Lipo battery, and a high-quality waterproof solar panel is mounted outside the enclosure to keep the battery charged. In some cases, a separate alkaline battery pack can be added to provide the higher voltage needed for some sensors. We designed and built a custom interface shield that has sockets for the various sensors, making connections in the field very simple and dependable. Sensor cables exit the case through waterproof cable glands, and brackets are bolted to the case back to allow for easy mounting to any diameter post. In the photo above, an adjustable bracket on the top of the post holds the solar panel and a solar quantum radiation sensor.
How well does you LiPo hold up under extreme cold? What is you data transmission rate? I know in the one I’m working on for NWS I’ve had to put the 2560 and the Xbee 900HP to sleep when not in use to conserve power. We are looking at a 7.2aH SLA battery with solar and regulator.
I’ve had loggers out for several very cold winters now, and I haven’t had any issues with the LiPo batteries due to cold temperatures. The only times I’ve had problems was using them in clear enclosures during the summer because the inside of the case turns into a mini-greenhouse and heats up the batteries (and the logger boards), resulting in erratic behavior of the board and occasional swelling of the batteries. But since we switched to opaque enclosures, I haven’t had any problems in the summer heat.
Do you have any more details or code that you might be prepared to share. I am struggling to create a sketch that will fit on stalker when using a gprsbee to send data, using the standard libraries.
Steve, when I first read your comment I was a little confused. I haven’t used the stalker board before, but I was under the impression that it was a ATmega2560 and not a 328P. I couldn’t figure out why you had code constraints…….
I spoke offline with Steve Hicks about the 2560 logger board I had done. If the community thought it would be useful I could redesign that to be more useful to this community and make it available. I would just need to know what the most prominent portions of the stalker or other board needed to be implemented and what the size constraints might be if any.