Getting those final test runs in

After a few days in the garbage pail simulation, I figured we'd get a realistic current usage for 24 hours with all the circuitry running.  We put a  Vernier current logger in line and took readings every  6 minutes.  Vernier has a good statistics function so I could get the total consumption over the day (the integral- for all you calculus folks).  Pretty much was as predicted ~.84 amps/day.  Definitely puts us comfortably in the zone for leaving the station for a month with a 42 amp-hour battery (50 days, in theory). .  There's enough room in the box to put two batteries in parallel for a seasonal duty cycle, but we'll hold off on that until this project proves it's mettle over a 30 day field test.

Water buoy-proof of concept phase

Testing it out in a municipal waste bin filled with water- water goes up and down with the rain and some occasional hose input.  Decided to put the steel pipe aside and go for schedule 80 PVC held with three pieces of rebar at 120 degrees separation each driven well into the creek bed.  I couldn't imagine doing this in anything bigger than very small tributaries with such a design, but that's what we're testing.  Looking to get it out in a few days.  Have a couple of ideas for securing the battery and for providing a bit of ventilation for the hydrogen gas that would emit.

Cutting Pipe for our Buoy Design

The idea is to have a dense foam cylinder inside a pipe in the stream that rises and falls with the stream level.  The pipe is vertical, and held by rebar, big rebar.  The probes will stick out of the cylinder while the cables go up into a sealed, watertight box where all the circuitry and battery are stored. I'll try to have a diagram out soon.  Pipe is expensive.

Francophone readers and commenters welcome

I've noticed that a fair number of blog guests are from the Francophone world, mostly France.  While I can't say that I'm an absolute master of the language (to say the least!), I d speak it fairly well and welcome any feedback or questions in the language.  Ce serait avec plaisir, mais veuillez m'excuser si mon ecriture est plein de fautes grammatiques. 

Check out my tutorials on Youtube

I've only got some rudimentary stuff up so far, but I do have a channel on Youtube where I post 5010 minute tutorials on various parts of our project.  So far, it's stuff that's covered pretty well already on other sites, but I have some fresh ones coming up soon that are more specific to the project and won't necessarily be found elsewhere, at least in the way that integrates Arduino with other things.  Upcoming videos include:  using MOSFET's to save power, hacking into the Sparkfun Vernier shield, and making a simple voltage regulator/charge controller for solar recharging of system batteries.

jeff's in town

Jeff Branson, the Gypsy Engineer from Sparkfun, has been evangelizing the masses with can-do spirit, sharp ideas, and mad skills. Here he his showing some kids how to use the new Sparkfun Data service for those of us who need a simple, effective, free place to post data.  This writer is already staying up late trying to run with some top-notch suggestions he has made.

In other news, I went to Walter Wood Hardware to pick up supplies for our first couple of buoys.

Happy Thanksgiving!

hangout with brian

Some of the crew did a video conference with Brian Huang of Sparkfun about using sleep functions to reduce power consumption in our projects. As usual, no matter the topic, Brian was on top of it.  The kids took down his suggestions.  He also gave some ideas on how to get the data coming over the Ethernet shield at the North Chickamauga site to graph, rather than just print some numbers on a blank IP address screen.
The key right now is to bypass the initialization "Press D12" part of the Vernier shield so that the probes take readings automatically once power has been restored to the shield following the sleep period (which would be most of the day).  If we're going to try to get by with using only a 20 ah battery in the buoy and come only once a month to check in for data harvesting and power check, we need to squeeze every milliamp we can.