Hold on to your phone, don't send it to heaven, and why accelerometers don't really measure acceleration.

Here's a little advice.  Hold on to your phone.  There has been some discussion at work recently about an app that encourages you to throw your phone in the air.  When you do, it tells you how high you threw it. That's it.  Of course, it tells you how you did compared to others, thus encouraging you to throw your phone higher and higher until... well... I would image this story rarely ends well.  Eventually I would think either the smartphone isn't caught and it splatters on the concrete, or worse, it hits an unwitting bystander on the head.  The app is called SMTH which stands for "Send Me To Heaven," and it seems to be gaining popularity.  Resist!  I must say that I do love the quote in the marketing of this app, “Probably the last game I´ll ever play on my current phone.”  Someone is having fun.

Still, it is interesting to understand how this application works.  Some of you may assume that the GPS is used to track the altitude of the phone when you throw it, but this is not the case.  GPSes are notoriously bad at calculating altitude, so they cannot be accurate enough to measure a throw of a meter or two.  Most phones have no altimeter.  So how do they measure how high the phone is thrown?  It turns out that they use accelerometers and the same principle that makes astronauts experience weightlessness on the International Space Station, even though they are in orbit and very much under the effects of Earth's gravity (Disclosure: the truth is that I have no information about how they do it, but I know how I did it a few years ago and it is all about accelerometers).   You can learn a little bit about how accelerometers work in the little video I put together for you on part of this subject.

To understand how this is used to calculate height of a thrown smartphone, you'll have to read on...

I spotted Stanford's self-driving car

I saw Shelly headed over to Stanford last week

Last week on my way home from work, I spotted VW/Stanford's latest self-driving Audi TTS, Shelly.  These are the folks that brought us Stanley, the car that won the DARPA Grand Challenge back in 2005.  I managed to snap a picture (above) as it exited the highway.  The whole process would have been much easier if I had a self-driving car myself so that I could concentrate on taking pictures... maybe some day.  In the mean time, it was pretty cool to see this car since is is the one that raced up Pike's Peak and topped 120MPH on a track in Sacramento last fall... all driving itself.  Apparently the lap time on the track was comparable to that of a professional driver.  When I saw it on highway 280 last week, it was driving pretty gingerly; carefully using its turn signal and moving over to the exit ramp.

While self-driving cars aren't exactly common, one does see them around ever since they got the green light last fall.  There is always a driver in the driver's seat, but when in self-driving mode, they don't have their hands on the wheel.  It seems like I see the Google cars out driving fairly frequently, but this was my first time seeing the Stanford car.  It looks much more like a production ready vehicle because it doesn't have the big Street View camera on its roof.  I think it is all pretty exciting.

Those of you outside of Silicon Valley may not be quite so used to self-driving cars.  If you do, here is a little hint.  Don't get into an accident with one.  If you do, they have enough sensors and cameras to prove beyond the shadow of a doubt that you were at fault.

Garden Monitoring Gadgets

A Previous Year's Tomatoes from our Garden

Note:  This is just a teaser.  A full how-to will follow some time in the future.

As regular readers know, we here at Digital Diner have grown tomatoes and veggies every summer for years.  Recently, we've been experimenting with hydroponics.  It has been pretty amazing seeing how our hydroponics plants perform compared to our more traditional, geoponic garden.  We are still learning, but the results are quite impressive with plants growing much faster, with no herbicides or pesticides and using only a fraction of the water of standard gardening.  There are some complexities, like understanding how to manipulate the nutrients etc, but overall, we have been mightily impressed.

The trusty old SunSPOT
watching over the tomatoes

One of the downsides of this type of gardening is that the plants have trouble quickly if there are any problems with the system.  If a pump or a fogger fails, in a matter of a couple hours the plants wilt and suffer dramatically.  For this reason, Widdakay and I decided to work on a system for monitoring our plants and providing live feedback on the web.  We could have used a prepackged system like Pachube COSM Xively which is designed for collecting sensor data, but what fun would that be?  No, we have to design our own system.  We have some experience with this since for years we have been montoring the tomato plants with some SunSPOTs and soil moisture sensors.  Now we have conceptualized a rather complex system and started to implement it.  It is still a work in progress, but we got far enough yesterday that I thought I'd report on it now.

To start with, we like graphs.  The graph below shows live feed from the sensors in our hydroponic garden.  Right now we have only two sensors connected, but we can easily support several more.  The blue line shows the water level in our ebb and flow hydroponic system.  When it goes high it means that the pump has turned on and water is pumped into the system.  When it drops down, it means water is draining out of the system.  In this type of hydroponic system that cycle occurs regularly when things are working correctly.  When the water level gets too low (due to evaporation) the pump wont turn on and we will see it here in the graph.  Later we will implement some sort of alerts to tell us of this condition, but for now it's just a graph.
The black line shows moisture level in one of our aeroponic systems.  It is using a soil moisture sensor, so it isn't exactly designed for measuring humidity, but it sort of works.  Generally speaking, if that line goes to zero for too long, it means that the fogger is not doing its job and we need to take action. If all is going well, the graph is being updated every few seconds while you watch right now and you should see the blue line periodically bouncing up and down while the black line squiggles around somewhere above 0.  If not, either we are working on the system right now, or we have a problem.

Note that you can scroll around, looking back over historical data, by moving the bar at the bottom.  You can change the time scale by dragging the sides of the region at bottom or clicking one of the buttons along the top left to look at the last 5 minutes, 30 minutes, 6 hours, 1 day or week.

The technology involved in making this system is quite complex, but amazingly quite available to us common folks.  The basic system architecture is shown in the diagram below:

Moisture sensor inside an aeroponic system

We use some inexpensive soil moisture sensors that we found at Jameco.  The systems we are measuring are hydroponic, which means there is no soil, still these sensors fit our needs pretty well.  We connected these to a ChipKit Uno 32.  The ChipKit is a new gadget here at the Diner.  It is a device that is code compatible with an Arduino Uno, but with a much faster PIC32 CPU and with a bit more I/O.  (Stay tuned for full review after we get more experience, but so far we like it).  We chose it for this task because it gives us up to 12 analog inputs compared to only 6 on an Arduino Uno.  A simple C program on this board collects the sensor data every 10 seconds through the analog inputs and sends it over the USB port to a Raspberry Pi.  (We may try replacing the Raspberry Pi with a BeagleBone Black in the future)  The Raspberry Pi runs a Python program that massages the data into appropriate formats and then connects over WiFi to stuff the data into a MySQL database on a server.  We then use a little Javascript and a very cool package called highcharts (free for personal and non-profit use) to plot the data from the database and handle the live updates.

ChipKit being installed on the ebb and flow system

All the code is in a GitHub repository that we will publish here when we get a little further along on the project.  For now, just let us gloat a little about the cool live graphs we got working this weekend.

Quick hint for Beaglebone Black user

A little while ago we announced the arrival of the BeagleBone Black development board.  It's the Arduino-like board that gives you a full Linux computer for $45.  I've been playing with one in my spare time for the last few days and I have discovered a neat trick.  I hope to have a full review at a later date.

The BeagleBone Black and Raspberry Pi and other such development platforms are very powerful, and it is amazing that they are essentially stand alone computers for under $50.  However, they suffer from being so gosh darn small that just the cables required to connect them up can be overwhelming.  With the BeagleBone  you need to connect power, Ethernet, HDMI for the display, keyboard and mouse (usually via a USB hub) if you want to see the full glory of the graphical user interface on the BeagleBone.  All these wires detract a bit from the beauty of a device that can fit inside an Altoids mint container.  Meanwhile, my much less powerful Arduino just hangs off a single USB connection, beautifully simple in its single umbilical configuration.  Why do these more powerful boards have to come with so much complexity?  There must be a better way.

Too many cables!

One really nice feature of the BeagleBone Black is that when you plug it in to your computer via USB, in addition to getting power from your computer, it also connects as a disk drive and a network connection so that you can load required software from it and communicate with it for control.  That started me thinking.  I use other Linux computers remotely via a protocol called Virtual Networked Computing (VNC).  It allows me to open a remote desktop on the Linux box in a window on my laptop.  Why can't I do the same thing with the BeagleBone so that I don't need all those wires?   It would allow me to get rid HDMI display connector (since I would use my computer's display) as well as the USB keyboard and mouse (for the same reason).   It even frees up the USB port so that I can connect a USB WiFi dongle to get a network connection.  I've certainly used VNC on BeagleBone and Raspberry Pi before over WiFi or Ethernet, but what is different here is using the virtual network connection of the BeagleBone power/USB connection so that I can get rid of wires.  If I can get that working, I'm back to a single cable connecting the BeagleBone to the laptop and I'm good to go with all the graphical power of this beast..  Well, it turns out you can do this and here's how.

First, you'll need to install the VNC server on your BeagleBone Black.  Get all your cables connected so that you can boot it up with a good network connection and type these commands to the terminal:

opkg update

opkg install x11vnc

It should go through a few steps and then eventually tell you that the software has been installed.  Next you'll want to start up the VNC server.  This is the tricky bit because of the way the X Window system works, if you don't open it from within a window session, you need special authorization to connect.  The following line figures that authorization out for the default Ångstrom Linux version that ships with the BeagleBone Black.  Other versions may have a slightly different command.  In Angstrom, type this to the command line:

x11vnc -bg -o %HOME/.x11vnc.log.%VNCDISPLAY -auth /var/run/gdm/auth-for-gdm*/database -display :0  -forever

Now all that is left is to go to your computer (that the USB cable is connected to) and run your favorite VNC client.  I use the old standby Chicken of the VNC on the Mac, but there are plenty of others.  Connect to 192.168.7.2 and you should be able to see and control your BeagleBone GUI from your computer.... without all the wires.

The BeagleBone screen shows up in a window on my Mac screen

This is a pretty simple little trick but it can make development much more convenient.  You just need the BeagleBone Black and one cable.  I haven't tried this with other operations systems, the original BeagleBone, but with appropriate drivers, it could be possible there as well.  I don't think this is possible on the Raspberry Pi because their is no USB device side connection.

Flying without fuel is cool!

We got to see the Solar Impulse this weekend, and I must say it is truly inspirational.  This is the solar powered airplane that has already been able to fly for more than 24 hours straight.. meaning aside from the issues of keeping the pilot awake, they can stay up as long as they want.   They will be flying the plane from here to New York City starting next month.

The challenge of building a plane like this is to find just the right combination of strength, weight and power to stay aloft without using traditional fuel.  To do this, they created a plane with the wingspan of a Airbus 340 jumbo jet (over 60 meters), but the weight of a small car.  As you can imagine, some advanced materials were required to pull this off.  The fuselage is made of carbon fibre-honeycomb composite  that is essentially two thin carbon fiber layers with what looks like light weight cardboard between them.  Bix is holding a piece of it in the picture on the right.  It is incredibly light and sturdy.

The wings and the tail are covered on top with solar cells (I'm holding six cells in the picture on the left).  Actually, that isn't quite accurate.  I should say, the tops of the wings and tail are made of solar cells.  The surface of the wing is composed of these solar monocrystalline silicon cells that are a mere 150 microns thick so they can be light weight, flexible, generate a lot of power and provide the necessary structural integrity for these jumbo jet-sized wings.  The cells are efficient enough to generate four electric motors humming along while completely charging the batteries.  This allows them to run down the batteries over night and then recharge them without landing during the day.  

There are four main batteries corresponding to each of the four main engines onboard the Solar Impulse.  Each of these batteries weighs about 90 kg (~200 lbs) and make up about one quarter of the weight of the entire plane.

A part of an incredibly lightweight wing rib

The single seat cockpit of the Solar Impulse

The motors on the Solar Impulse are approximately 10 horsepower each, or about the same as the Wright Flyer had back in 1903.  These motors are able to pull the Solar Impulse to its 22 mph takeoff speed and ultimately to its cruising speed of about 40 mph.  During the day, the power produced by the solar panel is enough to fully charge the batteries while it drives the motors enough to allow the plane to climb.  In the evening when the sun goes down, they plan to have enough altitude to glide.  Over a 5 hour period they are able to lose only 7000 ft.  Unlike traditional gliders, they don't do this by seeking thermals.  The turbulents associated with these up currents in the air don't mix well with such a large and fragile ship as the Solar Impulse.

In 2015, they are hoping to circumnavigate the world without using a drop of fuel.  At 40 mph, you can see that this will take quite a bit of time.  Even though the airplane can fly continuously, there is no real autopilot or automatic way of flying the plane and it only has room for a single pilot, so the human becomes the limiting factor.  They will have to land regularly in order to allow the pilot to sleep.  As you might imagine crossing the ocean will be a significant challenge.  It will take about 5 days and nights to fly across the Atlantic ocean.  In order to stay awake for this period of time, both the pilots, Bertrand Piccard and Andre Borschberg have special techniques they will employ.  They believe that through self-hypnosis and meditation they will be able to fly continuously for over 100 without real sleep.  The ground crew person that we spoke with about this topic said that they will allow them to have 8 - 20 minute cat naps.

Bertrand Piccard and Andre Borschberg

Both Bertrand Piccard and Andre Borschberg were there when we visited.  Mr Piccard gave a rousing speech about the importance of taking risks and trying things.  He should know.  His father was the first person to go to the bottom of  the Challenger Deep, in the Mariana Trench.  Bertrand himself has piloted a balloon around the world.  My favorite part of his speech was when he talked about trying go around the world three times.  He said the failures were learning experiences and that a success is a situation where you tried one more time than the number of times you failed.  Cool!  Mr Borrschberg then talked about the technical details of the plane and its planned flight.

Solar Impulse Specs
Wingspan	63.40m (208 ft)
Length	21.85m (72 ft)
Height	6.40m (21 ft)
Take-off speed	35km/h (22mph)
Average speed	70km/h (43 mph)
Maximum altitude	8,500m (27,900 ft)
Solar cells	11,628
Motors	4 x 10hp electric engine
Weight	1,600kg (~3500 lbs)

"For success, it is only necessary to try one tome more than the number of times you fail"

Aeroponics for all! Getting a cause funded.

Help Team "Awesome is What We Totally Are" 

with their PiggyBackr campaign, Aeroponics for All.

Today's post includes a request for your help.  Please read all the way through.

By now many of you have heard of Kickstarter or Indiegogo.  These are the websites that are allowing entrepreneurs to raise money to start a new venture.  The process is called crowd funding.  Rather than going to Sand Hill road and getting money from venture capitalists, these websites allow participants to take their plea directly to the people.  Widdakay and I met a developer who was struggling to get his watch project funded.  6 months later, he had a successful Kickstarter campaign that was able to raise over $10 million.  Needless to say, he isn't struggling with funding any more.

Last week, a new Kickstarter project popped up to build a small hydroponic garden, not unlike the system that Bix and Widdakay (and the "Awesome is What We Totally Are" team) teach about in their classes.  In the first week of this campaign, Click & Grow has raised over $250,000!  While congratulations are in order to them, it was a nice confirmation of the interest that hydroponic systems can generate.

The Click & Grow success is also very timely, because the "Awesome Team," was already busy preparing a crowd funding campaign of their own.  They aren't funding a start-up company, but they would like to raise some money to offset some of the expenses of teaching their aeroponics classes.  Fortunately, a new website is launching that will help people, including kids, raise money for a cause.  The new site is called PiggyBackr, and it is designed to help sports teams and student causes benefit from the same type of crowd funding that Kickstarter and Indiegogo projects enjoy for start-up companies.

The "Awesome Team" put together a campaign called Aeroponics for All.  Watch the brief video above to see how the "Awesome Team" is seeking donations to continue teaching their classes and research on aeroponics.

This is where you come in.  We would really appreciate your help in spreading the word about their campaign.  Please, post, tweet, email or tell your friends about Aeroponics for All.  We would love to spread their  message as far and wide as possible.

Of course, if you can spare any amount (even if not listed on their page) it could help them reach their goal.  And, if you know of some kids who have a fundraising project of their own, tell them to check out PiggyBackr.  You can see other PiggyBackr campaigns here.

Link: Aeroponics for All

Happy Festival of Photons!

Bix in St Lucia garb lighting up this dark morning

Today, here at Digital Diner, we celebrate a tradition that plays out in homes all over Scandinavia.  It is St Lucia Day, or the festival of lights.  In this tradition, on one of the days of the year with the least amount of daylight, the oldest gril of the family wakes up early, dresses all in white with a red sash and a wreath of candles in her hair.  She brings her parents some saffron buns and coffee in bed while singing (or at least playing a recorded version of) the St Lucia song.  It is quite a sight for a dark winter morning to see Bix bringing us yummy homemade baked goods by candle light.

Saffron buns fresh out of the oven.  Yum!

Of course, because of our geek/scientific influence,  rather than the festival of lights, I like to think of it as the festival of photons.  You see, at this time of year, there are fewer photons than ever hitting our hemisphere of this big blue marble that we live on, so each photon is precious.  What better time to honor our little friend who brings us light, than now when it is so rare.  We need to celebrate this quanta of wave-particle goodness that literally brightens our day.  So on this dark winter day, I salute you and thank you dear photon.

Happy Festival of Photons!!

Build your own Awesome Aeroponic Garden

A few weeks ago, Digital Diner's own Bix and Widdakay (half of the Awesome Is What We Totally Are team) taught a class on Aeroponics at Workshop Weekend (see their presentation here).  It was a smashing success.  In case you missed that, now, thanks to the magic of the web, you can build your own Awesome Aeroponics Garden in your own home.  More on that in a minute.

First, on a personal note, let me say that I am a convert.  When the kids started out on these hydroculture projects I thought it was interesting and I was curious to learn about it, but that was the end of it.  As I've learned more and more about it, it has convinced me this is very important technology and a key to our future on this planet and beyond.  The benefits and efficiencies are really compelling and I encourage anyone with even the slightest interest to learn more.  I'm sold.

Aeroponics (or fogponics in this case) is a form of Hydroculture (growing plants without soil), but rather than delivering nutrients to the plant roots via flowing water, in aeroponics, the nutrients are delivered in the form of a mist.  The process was developed by NASA who hopes to use it to grow plants in space.  Small (5-10 micron) aerosolized droplets of water enriched with nutrients float around in a root chamber where the plant roots dangle freely.  The roots can efficiently absorb the droplets and grow quite quickly producing up to 13 crop turns per year rather than about 5 using traditional techniques.

We have seen this in practice when we planted some lettuce in our traditional garden (geoponics) at the same time as we planted it in one of our hydroponic systems.  The picture below shows two leaves that were harvested at the same time a few weeks later; one from the traditional, geoponic garden and the other from the hydroponic garden.  The results really impressed us.

Geoponic lettuce on the left vs hydroponic lettuce on the right
The hydroponic lettuce is dramatically larger

Hydroponic methods recycle water very efficiently, so it is estimated use up to 98% less water than traditional methods.  These systems generally need no pesticides or herbicides.  They offer incredible control over the environment the plants live in, allowing one to tune it to particular needs of the plants.  For example, we have some strawberries growing in one of our Awesome Aeroponic systems.  We would like them to start producing strawberries, so we have moved the system inside where it is warmer and varied the nutrients in just that system to encourage the production of fruit.  We would never have that kind of control using traditional means.

Hyperlocavorism

These systems are really engaging and interesting to watch grow.  We have been experimenting with several different types of systems here at Digital Diner and I'm happy to say that it has turned us into hyperlocavores.  While locavores eat food that is produced locally in order to get seasonal, fresh, produce that is grow to be eaten rather than transported, we have taken that to the extreme of growing our own food.  In a very small bit of space, we are growing enough lettuce to provide our family of four a salad almost every night.  The food we grow at home never has pesticides, spends time on a truck or in a grocery store, was grown in a water efficient way and is always fresh and tasty.

The system that team Awesome Is What We Totally Are has designed is small and portable and capable of growing herbs, lettuce, strawberries and all sorts of great stuff.  Go build one for yourself and try it out.  It isn't very expensive (~$40),  doesn't take up much space, and yet can produce some delicious food for you and your family.

Build your own Awesome Aeroponic Garden here!
Learn more about hydroculture from the Awesome Team here!

Team Awesome Is What We Totally Are
"Make What Matters"

Lots and lots of birds....

Lots and lots of birds... really lots!

Click on the picture above and examine it a little closer.  Go ahead.  It is not the work of some crazy person with Photoshop.  It is actually a picture we took on Friday, as shot from our camera.  There really were that many birds all flying in close proximity.  It was crazy!
Every now and then, instead of eating a bird (Turkey) on Thanksgiving we head off to central California to watch birds.  There are several wildlife preserves there that have literally millions of birds. Now we are NOT big birders or anything like that, but when you get over a million of just about anything in a small area, it often makes quite a spectacle.  This is the case with these birds, mostly Snow Geese, that winter in central California.  We visited three areas, Sacramento National Wildlife Refuge, Colusa National Wildlife Refuge and Gray Lodge Wildlife Area.  We saw Geese,  Ducks, Cormorants, Egrets, Herons, Vultures, Hawks, Coots, Grebes and plenty more.  The most amazing thing was the pure number of them.  The noise of the geese was a cacophony of sound that is best described as the cross between a large crowd at a football game, and what it might sound like if you could listen to all the telephone connections in the country at once.  Take a look at the (a bit shaky) video below that we shot, for some idea of what it was like.

Global Warming and the Power of Crowd Sourced Data Collection

I just saw an interesting article at the Grist Mill that shows some of the statistics of global warming.  According to the data they have seen from NOAA, no place on the planet has seen record cold temperatures so far this year.  In fact, October was the 332nd consecutive month with a globally, above-average temperature.  That means that anyone 27 years old or younger has never experienced a globally colder than average month.  Pretty astounding.

Another interesting part of the article comes from Jeff Masters of the Weather Underground. He claims that the drought of 2012 will prove to be ultimately more damaging than superstorm Sandy was both in terms of deaths and financial damage.  That's pretty shocking.  The conjecture is that both the drought and the storm were aided by higher than normal temperatures.

Of course, for some reason global warming is a hot political topic with accusations of faked data and all sorts of nasty conspiracy theories.  Weather Underground helps me justify my stance on this issue... see below.

The Digital Diner Weather Station

Aside from the gloomy news on global warming, I think that it is interesting that they quoted Jeff Masters from Weather Underground as an expert on equal footing with scientists at NOAA.  We have been streaming data from our weather station here at Digital Diner continuously to Weather Underground and HamWeather (a lesser known weather service) since August of 2001 (11+ years!!).   Weather underground is a crowd-sourced sensor network of weather information where people like us contribute data from their personal weather stations.  They are collecting data from 36,000 stations around the world which is very likely more than NOAA is collecting.  This data can help lead to new understanding of really big issues like global climate change.  Let that settle in for a second.  A bunch of random folks can actually contribute to one of the biggest scientific issues of our time.  That may be why this database of weather data from regular folks like us has become valuable enough that the Weather Channel has announced their intention to purchasing Weather Underground.

Little Sister is Watching

I've got an extensive background in the study of sensor technology and I've heard many concerns about what happens when these sensors proliferate and the government can monitor our every move.  Will this technology help move us toward a state where Big Brother is always watching us?  I think we are already seeing some of this, just visit an airport for examples, but I also think we are seeing something else.  It turns out that little sister is watching too.  By "little sister" I mean the rest of us.  It's not just the government monitoring us.  We can often monitor the government, big corporations and any other conspiracy promoting organizations you don't trust using the same type technology.  While there may be people who argue that the government has some particular reason for wanting us to believe their data in support of global climate change, we have a more extensive set of weather data from non-governmental sources - the Weather Underground (incidentally the name Weather Underground a reference to a 1960s militant radical student group the Weather Underground).  I can't vouch for all the data on there, but I can tell you that at least our data from our weather station is accurate.  I think there are many other amateur meteorologists out there who can vouch for their own data on Weather Underground, and in this case it seems to correlate with NOAA data pretty well, so that makes me believe it is all accurate.  The temperature of the Earth is rising.  The bigger point is, so is our ability to understand our world.  Sites like Weather Underground, HamWeather and Cosm are providing a way for us to collect and share data to reach our own conclusions, not those fed to us by those who may have their own agenda.  Just as Wikipedia has become the defacto first source of information (the internet encyclopedia if you will despite the fact that schools are fighting it) there are new sources of information popping up every day that are created by people like you and me.  It is making it harder and harder for anyone to pull off an elaborate hoax.

Please dear readers, go prove to yourself that the world is as you believe.  If you question whether or not the world is round, send up your own balloon to take pictures.  If you want to know what's happening with sea life in the San Francisco Bay, volunteer to help count oysters and see for yourself.  Rather than getting bogged down in political debate, go do some science for yourself!

Now back to your regularly scheduled program.

Counting Oysters in the San Francisco Bay

The Watershed Project offices

Yesterday we visited the Watershed Project in Richmond to help them with their study of oysters in the San Francisco Bay.  

The oysters are making a comeback after a problem that started back in the mid-1800s.  Apparently, during the gold rush, the miners used a method called hydraulic mining.  They pointed a high pressure hose at the hillside and sprayed away all the soil to just reveal the gravel and rocks beneath it.  This left them with a much easier task of separating the valuable rocks from the others.  Widespread use of this technique caused a huge amount of mud and silt to be washed down from the Sierra Mountains into the San Francisco Bay.  This was very bad news for the oysters because they require a hard surface to cling to.  As all the rocks became covered in silt, the oysters died off.

Oysters are filter feeders that can each process up to 20 gallons of water per oyster per day.  In that process, they remove nitrogen-containing compounds and plankton from the water.  This tends to help overall water quality and has an impact all the way up the food chain, so they are vital to the ecosystem.

Bricks from around the bay waiting to be counted

The Watershed Project is hoping to create new habitats to promote oyster colonies to help the overall ecosystem of the San Francisco Bay.  As part of this work, they are studying where oysters are likely grow by placing bricks in the water at various candidate sites around the bay on specially designed stands.  The Oysters like the hard surfaces these bricks provide.  They place the bricks in August and in November (now) they re-collect them to see what has grown.  It was our job (and other volunteers) to help with counting the number of oysters that were on the rocks.

A muddy brick ready to be counted

The bricks had been retrieved and carefully organized by other volunteers so that we could tell exactly which brick came from which location, how it was oriented and its depth in the water.  We then proceeded to count and record each oyster on the front, back, top, bottom and sides separately.  With only three months of growth, many of these oysters were very small (as small as 1 mm), but it was our job to count every one on each brick.  We had to differentiate between oysters, barnacles, limpets and other clingy critters.  Differentiating between these different aquatic bivalve, arthropod and gastropod mollusks was a bit daunting at first, but we quickly got the hang of it.

It was messy detailed work, but somehow very satisfying

Bix and Widdakay hard at work

Workshop Weekend Reminder

A little reminder for San Francisco Bay area folks - We mentioned earlier that this coming weekend (Nov 10-11) will be the Workshop Weekend program in Oakland, and that among the classes will be something called "Awesome Aeroponics"which will be taught by Digital Diner's own Bix and Widdikay and friends.  We have some more good news.  If you sign up and use the coupon code AEROPONICS2012, you will receive a 25% discount on your registration.

I don't know about the other classes, but I can tell you that Awesome Aeroponics will be entertaining and informative.  You will learn about everything from Hyperlocavorism to Deep Water Culture, Nutrient Film Technique and Dutch Buckets.  In the end you will build and take home your own Aeroponic garden which you can use to grow a variety of different decorative or delicious plants in your own home or yard.  It will be a great class.  Come join us!

Tasty Mex Hexaflexagons at Digital Diner

We did it!  We couldn't help ourselves.  We were inspired by Vi Hart to make the tasty hexaflexagon treats that you may have read about here on Digital Diner (If you have no clue what I'm talking about, you can catch up by reading read our previous posts here, here and here).  It was fun, educational, and mostly delicious.  We encourage any other curious readers to try for themselves.  IMPORTANT!  First, be sure to watch the safety video below... Even if you aren't going to make the hexaflexagon treats, you should really watch the video.  It's outstanding!

How to make your own Mex Hexaflexagon

Once you have watched the safety video, you should refresh memory by watching the Mex hexa flex video.  Also, before you start, you must get yourself some large tortillas.  Then the fun begins.  We found that in order to make the most efficient use of the tortillas, we cut each one in half and then cut a long strip from each side.  We calculated that in order to create the required 10 triangles, we needed a ratio of about 5 : 1, length : width of the strip of tortilla (actually 5 * 2 * cos( 60˚) : 1 which equals 5 : 1).  If your strip is too wide, say a 4 : 1 ratio, you won't be able to create the required ten triangles.  If your strip is too skinny, say a 6 : 1 ratio, you will have a very tiny hexaflexagon and end up with excess length of tortilla to cut off.  

Tortilla cutting

Next is the folding.  It can help to practice with paper first.  With a little patience we were able to fold some fine flexagons.

A tortilla hexaflexagon

Next you add yummy stuff.  Like Vi Hart, we put guacamole and sour cream on the first layer.

Then you must flex your flexahexagon in order to move the gooey goodness to the inside.  It is important to notice that because of the constraints of gravity, it is necessary flex your hexaflexagon by lifting up three vertices and opening up the bottom as Vi Hart does in her video.  If you are lucky it will flip nicely inside out.

After that, you need only to garnish with more yummy stuff.

 Then it is time to eat it.  It is quite a pleasant little gooey, messy treat.

Don't take our word for it.  Try for yourself!

We have some ideas for how to take it up a notch... stay tuned.  If it turns out, we'll publish the result here on Digital Diner.  If not, then forget I said anything at all.

Awesome Aeroponics : Workshop Weekend

Plant roots growing in a soil-free aeroponics system

November 10-11 in Oakland, CA there will be a Workshop Weekend.  It is a great event where adults and kids alike can learn all sorts of things to enrich their lives.  In particular, you should all plan to attend because among all the other wonderful classes is one called "Awesome Aeroponics: The Art of Soil Free Gardening" which will be taught by a group called Team "Awesome is What We Totally Are".  This team was founded by Digital Diner's own Bix, Widdakay and some friends.
If you attend this class on November 10 at 1pm, you will build your own Aeroponic Garden system that you can take home with you!  Don't know what Aeroponics is?  It's the latest in high-tech, soil-free gardening.

Leaf on the left was grown in soil while the one on  the right was
grown in "Awesome is What We TotallyAre" high tech garden

The two lettuce leaves above show how awesome this technique is.  We planted two similar sized lettuce plants on the same day.  One was put in soil in our garden.  The other was grown using soil-free techniques.  As you can probably guess, a few weeks later we picked them and the one on the left used the traditional methods while in the same period of time the one on the right grew to about three times as large.  In the class you'll learn about hydroponics, aquaponics and aeroponics (which we collectively call *ponics). And best of all, in a couple of weeks you can start eating food from your own aeroponic garden.  This class promises to be educational, entertaining and hyperlocavoric.

Workshop Weekend will be a great event with a wide variety of classes for all age ranges to take.  Topics include how to roast coffee, liquid nitrogen ice cream, designing for 3D printers, how to build a web site, build a Gieger counter, MacGyver class and plenty more...   They all look great!

Plan to attend!  Sign up now for Workshop Weekend

Awesome is What We Totally Are - Team

Arduino Uno vs BeagleBone vs Raspberry Pi

This is a post specifically aimed at our budding Makers out there.
We like to build stuff here at Digital Diner.  There is always some sort of project going on.  These days, most of our projects include some sort of digital component - a microprocessor.  If you haven't gotten bitten by the Maker bug yet, we strongly encourage it.  It can be incredibly rewarding.  If you have even a minimal understanding of programming, there are websites, platforms and tools to help you develop your skills to the point where you actually create a hardware device with buttons, knobs and servos - a real physical world gadget.  Software is fun, but when you can make your project physical it is even better.  

There are so many great platforms for creating digitally enabled devices that its gotten hard to figure out which one to use.  For example, we are currently building a hydroponic garden project and had to choose a controller to run the pumps, read the sensors etc.  We were surprised at the number of choices that were available to us.  It can be a little confusing for the beginner.  To help, we've taken three of the popular models and compared them so that you can choose the right tool for your next project.  Spoiler: we recommend all three.

The three models (all of which we use here at Digital Diner) are the Arduino, Raspberry Pi and BeagleBone.  We chose these three because they are all readily available, affordable, about the same size (just larger than 2" x 3") and can all be used for creating wonderful digital gadgets.  Before we get to the comparison, here is a brief introduction to each one.  

Arduino Uno

The Arduino Uno is a staple for the Maker community.  Arduinos come in various sizes and flavors, but we chose the Arduino Uno as an example of the prototypical Arduino.  It has an easy to use development environment, an avid user base and is designed to be easy to interface all sorts of hardware to.

Raspberry Pi

The Raspberry Pi is the newcomer to the game.  It isn't really an embedded computer.  It is actually a very inexpensive full-on desktop computer.  It is barebones, but at $35 for a real computer, its worthy of note, and it is a great platform for lots of Maker projects.

BeagleBone

The BeagleBone is the perhaps the least known of these platforms, but an incredibly capable board worthy of consideration for many projects.  It is a powerful Linux computer that fits inside an Altoid's mint container.