meteohub.de

Hurricane Gustav will be coming through my area here in the next few days. I'm trying to make sure that I will be able to keep recording data on the Meteohub, even if I can't upload it online to Weather Underground. Does anybody have any suggestions for ensuring continuing operation even during power outages? My Davis Vantage Pro2 has a battery backup in the console that will last for days, so really the only thing I need to power besides the router, cable modem, etc. is the NSLU2 running meteohub.

Any information or suggestions are welcome.

Helo.

You should probobly buy one big or more small UPSes, that should provide electricity to your nslu2. This would be an good option if the electricity would disapear for some hours (depends on the size of the UPS). When the electricity is basck it will charge for the next time it is needed. If you have a chance maybe an small generator would also do a great job - maybo only for charging the UPS (the gen. runs for some hour or so that the UPS is filled and then u turn it off and again onn some hours later..). This is how i would it do if i had something like that in my mind... The modem and the router doesn't has to have electricity - the nslu2 need it - ok, the infos won't be readable in "real time", but who cares? you will have all the data, so you can show it later then...

Regards

Thanks for the info urosh. That's pretty much what I have planned. I have the NSLU2 and stuff on a UPS right now, but I'm going to need to take everything else off the UPS to get maximum runtime for meteohub. I guess now all I have to do is wait.

Here's some quick and dirty math for determining UPS run-time with the Meteohub.

The NSLU2 uses "less than 10 watts", or (in the USA at 120V standard), just under 0.09 amps of current at a given moment in time. Over a 24 hour period, the system will use approximately 2.2 amp-hours of electricity.

Typically a home UPS is meant to provide about ten minutes of power for a high-load computer system with a big power supply (300W) and a monitor drawing an additional 60-100 watts, for a total of about 4 amps of current at any given time. Thus the Meteohub is at least 40 times more power-efficient, so it should last at least that much longer on a UPS (so if a computer lasts ten minutes, the Meteohub should be okay for nearly seven hours.)

Additionally, your UPS case or instructions should list the rated amp-hours of output (in addition to the more prominent "volt-amp" rating, which gives the maximum load it can handle, but not the length of time), and from there you can extrapolate how much time the Meteohub should run off the batteries in that setup.

My station is on an APC Back-UPS BK650MC with a brand-new battery I installed 2 weeks ago. It's rated for 650VA.

In theory, you're right. The Back-UPS runs off of a 12v 12ah battery. However, what I'm most worried about are the inefficiencies of inverting the power from 12v DC to 120v AC, then back down to 5v DC for the NSLU2. Lots of wasted efficiency. For next time, I'm going to build a little voltage regulator that will put out a max of 2a at 5v to hook up to a big gel-cell battery that I have.

But, for now, this will have to do. I'm at college 2 hours away from my station, so it's up to my parents to keep it up and running. I actually did a decent job of wiring all of the network components and everything, so it should be easy to see what to unplug from the UPS to keep the NSLU2 running for as long as possible. The station itself runs off of solar power, and the console can run for a month off of internal batteries.

My whole setup (including UPS) draws 29 watts from the outlet when it's running... that includes the NSLU2, Davis console, an Apple Airport router, a Linksys WAP11 wireless access point, another switch, and a Panasonic net camera. It draws approximately 36 watts when the UPS is charging its battery.

We'll see what happens!

Hello.

Let's wait and hope for the best...
Can you also provide the adress of ur weather station?

Cheers!

My station is KLAALEXA5 on Weather Underground.
http://www.wunderground.com/weatherstat ... =KLAALEXA5

I'm station D0240 on MADIS through CWOP.

I will keep the Internet connection up as much as possible, but I am going to have to upload historical data after the fact. My primary objective is to keep the NSLU2 up during the storm, with the weathercam, router, and cable modem taking second priority.