Our 2011 Christmas Tree

Here is a picture of our Christmas tree with presents.  If you look closely you can see our ornaments.  We have a Christmas pickle, a surfing Santa, a red shiny ball and a snowman M made yesterday out of plastic and cardboard.  Below the tree is our Christmas light setup.  I added a potentiometer (variable resistor) to adjust the rate the lights blink by turning the dial, also there are now 10 LEDs.  It is powered by a 9 volt battery hidden behind the tree. 

Winter weather and random catching up

I can't believe it is almost Christmas; we noted the solstice passing two days ago.  The weather here has cooled slightly and is a bit more windy and rainy compared to a few months ago.  We are living on the dry, leeward, side of Oahu.  There are actually nopales (Opuntia cactus) growing here and there wild.  The grass in our yard was dry and brown but with the increase in rain lately it has started turning green and growing.  I took today off of work and T and I did some yard work to cut the grass and weeds.  Then I put both T and M to work to collect bits of trash out of the yard.  (We live in a densely populated area and small pieces of plastic can blow around and accumulate.)   Each day I have been watering some plants we have planted and I was worried about how dry it has been, but this increase in rain and cloudiness has helped a lot. 

We have adjusted a lot to the temperatures here.  When I say the weather has cooled this means it gets down to about 70 F before sunrise, perhaps in the high 60s.  We were laughing at ourselves when V said she was cold in the morning and I checked to see what the temperature was.  A year ago this would have been unbelievably warm. 

We use a clothesline in the back yard to dry our laundry.  Now that it is raining intermittently this would seem to be a problem, but if we don't get the clothes off in time the rain quickly clears up and they dry right out again.  A couple of times we have had heavy downpours, but so far the rain here has never lasted long. 

We drove around last night to look at the lights and decorations people have put up.  V and the kids went out again tonight to have another look.  There were several barges from the west coast that came in a month ago carrying Christmas trees.  They were selling like hotcakes at some of the stores around here.  We put up a small Charlie Brown tree for fun.  Next year I would like to decorate a small palm tree with lights.

I programmed our microcontroller to blink a series of different colored LEDs in various patterns as a Christmas decoration.  I tried to teach the kids how to count in binary numbers while doing it, but they seemed more interested in the "Knight Rider" pattern as the light sweeps back and fourth.  Here is a picture of the lights with the system hanging up from a hook on the wall and running off a 9 volt battery.

Here is part of the source code that flashes the lights in a binary integer series. 

There is a potential bug, the interior for loop should start with "count=(LEDnumber-1);" to make it more general.

In other news, V earned her first paycheck in years!  (She could not work legally in Germany because she was not an EU citizen.)  It was just a one time thing, but every bit helps.  She got paid to ... sleep!  She was a guinea pig in the control group for a medical sleep study.  I took care of the kids over night (we had a party!) and she got to go, get a good nights sleep while hooked up to monitors, and get paid for it!  I need to find a job like that.  It is too bad she can't do that more often, but V is job hunting for more permanent work. 

And here is a random picture:

If you look closely you can see one of our neighbors dogs relaxing on a back porch.

And here is a picture of F from this morning.  We are out on our back porch.  It is tricky to hold her and take a picture at the same time. 

Above is a picture of M in another project.  We are trying to make our own batteries.  We picked up some used film canisters from a local pharmacy for the containers and made the battery out of aluminum foil, pennies, felt, wire and diluted vinegar.  After hooking eight of them together in series we only managed three volts.  This one is still a work in progress. 

This is a giant centipede (Scolopendra subspinipes) that is native to Hawai'i and can give a nasty bite.  It was on the sidewalk in front of our house one morning.

As a final thing to mention on this update, the kids have had a lot of fun playing a computer game called minecraft lately.  You can play it as a single player, but I set up a server so they could play together in the same game world (my setting up the server seemed to impress them much more than showing them how to make a motor, radio or speaker out of household parts).  One one hand the game is simple, but on the other it can be very creative.  You mine blocks that have different properties and you can combine them to make new tools, etc.  You can also arrange things to build complex machines.  I was playing with them and we made an automatic harvester and a powered rail line you could ride on in the game.

New Tires and a Petition

In recent news.  We had to get new tires for our van.  The back ones were very worn and I had to keep pumping one up.  It got worse so that I was pumping air in every few days, so we went to costco and got them replaced a couple days ago. 

Also, there was a petition I was asked to sign and I refused.  It was to oppose the proposed repeal of a tax exemption.  I asked who was exempt and was told it was people over 65.  I asked, so retired people aren't paying for public schools, and was told yes.  I told her I'm not signing it.  Why should the richest people not help support public education for our children?  She didn't seem upset at all.  I think she was being paid to collect signatures. 

It frustrates me how little people value education.  The most important things for the future of this country is education.  Everything else, jobs, economy, security, healthcare, energy, ...  stems from a strong education, if you take a long term view.  Cutting education to focus on these other areas is a short term fix that hurts us in the long run. 

Lego Occupy Wall Street Gift Set

I thought this was funny. It is better viewed at the Slate site (may have a commercial first).

Microcontroller

There are a lot of posts in a row here but what we did is actually spread out over several weeks.  It's just that I finally have some time to catch up with communicating a bit.

In another project, I picked up a microcontroller and a breadboard and have been playing with programming it with the kids. Above T is cutting and stripping some hookup wire to put together a simple circuit with an input, pushing a button, and an output, blinking an LED; the breadboard is in his lap. 

Above is the completed setup. 

We wrote a program to upload to the microcontroller so that once the button is pushed the LED blinks our family name in Morse code.  Below is a screenshot of the IDE and the first part of the program that is uploaded to the controller. 

Lizard Production Gearing Up

Earlier I mentioned the anoles and geckos M had caught and placed into aquariums. 

Well now they have started laying eggs and tiny anoles have hatched. 

Also, V has set up a cricket raising facility to produce a steady supply of food for the lizards. 

Fox-Hole Radio

We built a foxhole radio as another weekend project a few weekends ago. 

First we strung an antenna (22 AWG) out the window to a tree in the backyard. 

Then I set up a ground wire using an outlet and a child safety plug to cover it (and a lecture to the kids about the danger of doing this wrong and exactly what I was doing and why).

(DISCLAIMER - Do not do this at home if you are reading this.  There are safer ways to set up a ground.  Stick a piece of metal into the dirt outside in the yard and connect the wire to that.)

Then we made some coils of wire over cardboard tubes and sandpapered off the enamel coating to tune the frequencies, and hooked up a diode on the other side of the circuit (in parallel between the antenna and ground).  The diode only allows current to flow in one direction, which removes half of the wave from the AM signal and allows the signal to be played in a speaker as sound waves.  The sound output for the speaker is between the diode and ground in the circuit.  The circuit has a resonant frequency that is adjusted by the length of the connected coil to filter different stations based on frequency.  We experimented with several different diodes and coils.

In the picture you can see a zener diode and a green LED (light emitting diode) both of which worked fine when hooked up in the circuit.  The trick is making your own diode.  I tried a few treatments of razor blade surfaces to a graphite pencil point in the circuit.  One blade I rusted in salt water and air for a few days.  Another was heated with a candle, which put on a layer of black carbon on one side.  Another I heated directly on an electric stove eye until it oxidized to a deep blue color.  The third one worked the best and is shown hooked up (with thumb tacks and cork board, no soldering here).  The pencil is held up and connected to the rest of the circuit by a bent safety pin.  The contact point of the graphite to the oxidized metal surface can be adjusted until a good diode contact point is found where the electricity only moves across in one direction.  We also tried a few different tunable coils with different lengths and wire sizes.  The one that worked the best was an intermediate size shown here (30 AWG).  The circuit is connected at different points along the coil to tune different radio stations.  It was very touchy a slight movement to the contact and the station was gone.  It worked better to add a capacitor to the antenna input side.

Above is the capacitor.  The antenna is connected to a square of aluminum foil placed in a book.  This is separated by a single page from another square of foil that goes into the circuit.  The radio can be fine tuned by placing different weights on the book, which changes the distance between the foil sheets. 

Here is the setup connected to our amplifier and plastic plate speaker.  We also plugged it into the microphone input on a laptop to monitor and record the signal with audacity.   Using an empty frequency, we were able to detect our home built motor running on another table by recording, noise removal and amplification.  The brush contacts in the motor acted as weak spark gap transmitter.  We were also able to get several local AM stations tuned in.  I identified three of them by the call signs and looked up their antenna locations online; they were 10 to 15 miles away.