The Davis Blog

What a great weekend!  We headed out to Shreveport to meet up with the Stuevers for a Mardi Gras weekend.  We went down and saw the boardwalk on Friday night and then the men got up early (like 5:30 early) and staked out a spot on the parade route for the largest Mardi Gras parade outside of New Orleans.  It was a VERY cold day but we had a lot of fun tailgating and waiting for the parade to start.  Finally, it did and it was a ton of fun!  There were cool floats, a great family friendly atmosphere and beads everywhere!  There are a bunch more pics on Flickr.  Check them out!

We were quietly driving down the road today when suddenly, Noah had a revelation.  ”Dad, I know what they use on those wires!”

“Huh?” I replied.

“Those poles that have the wires between them by the road.  I know how they attach them.” shoots back Noah.   “They use jingle bells.”  We got to looking and they kind of do look like jingle bells from a distance.  I guess that helps give you a place to store all of those holiday decorations.

It’s been a while since I have posted to the blog.  Since I am the one that heard Noah say something “They Said It” worthy ….. here I go.

As a reward for being SUPER NICE, Noah’s Kindergarten teacher passes out warm fuzzies (those little pom pom crafty things).  Well, while in Stillwater over Christmas break, we were lucky enough to be a part of  “The Oklahoma Blizzard of 2009″ (at least that is what it has been called by those on Facebook anyway).  So, we’re driving down the road and Noah says “It looks like there’s warm fuzzies hitting my window!”   Warm?!?  Not quite.

Tonight as I’m baking cookies, Little Mr Random Man comes into the kitchen and asks, “Why do we have skin?”  I answered in terms that I figured a five-year-old would understand.  “It’s there to hold everything we need to live in our bodies.  Like our heart, lungs and bones.”   Noah replies, “You should NEVER tell a dog you have bones in you.”

My little guy sure knows how to make me laugh!

We were watching my beloved Buffalo Bills play the Patriots the other day.  Noah told me, “My favorite football team is the Buffos.  They’re the best.  They’re even better than the Hawks!”  The Hawk is my school’s mascot and Noah thinks that our football teams are pretty awesome–they actually are pretty good.  Anyway, I’m thinking about switching my favorite team from the Buffalo Bills to the Buffos.  At least the Buffos aren’t about to miss the playoffs AGAIN.

Be careful with wishbones people! I have firsthand knowledge that when that bone breaks, sometimes it breaks hearts, too. Case in point:

All smiles!

Stretching to the breaking point.

SNAP!

I hate wishbones!  :(

We posted a ton more pictures in a set over on Flickr. Go check them out!

Check this thing out:

It’s a ginormous digital picture frame!  OK, so it’s also a TV, but we’re kinda pumped about this new feature that our Roku box has that allows you to stream Flickr slideshows to your TV.  The Roku is that little tiny black box on top of the DVR in the left of this picture.  It hooks up over wifi, so you don’t have to run network cables to it.  The pictures look AMAZING at that size and it’s super easy to add pics to it, too!

Just a few quotes we have to write down before we forget them.  They made us laugh.

Noah at the computer, “Daddy, I rememberalized my password!”

Myra, explaining something in detail, “I don’t remember pacifically what happened, but…”

Noah told us how the world works:  ”If you dig a hole in the backyard 10 feet down…and you crawl through it.  You’ll come out upside down in China.  You really will.”

I’ve been having some fun–and actually learning cool stuff–with my Nerdkit lately and I wanted to build a project that used nothing but the parts in a normal Nerdkit. I came across some intervalometer projects for Nikon cameras and since I have a Nikon, I decided to go with it.  There were some cool Arduino projects that looked pretty easy, but I wanted to build it with my Nerdkit because I planned on building a permanent one, and I didn’t want to tie up my Arduino inside of it.  I did end up having to buy one part that wasn’t in my Nerdkit.  It was an infrared LED from Radio Shack.  (I think it was this one.)

First off, what is an intervalometer and why would I want one?  An intervalometer is basically just a timer for your camera.  It allows you to take cool time lapse videos of things like a flower blooming, a sun setting, or ice melting (cooler than it sounds).  My intervalometer also has a camera remote mode so I can use it to take family portraits without having to run to get into the frame or use it to take pictures with a slow shutter speed that are easily affected by camera shake.

My intervalometer can be set to 8 different settings with a dial.  It can wait 15 seconds, 30 seconds, or 1, 2, 3, 5, 10 and 15 minutes between pictures. In reality, it can be programmed to any length of time, but  My Nikon D3000 will only stay on in remote mode for a maximum of 15 minutes.

The Hardware
Like I said earlier, you can build this thing with only a Nerdkit and an IR LED.  The setup is fairly simple.  The hardest part is connecting the LCD and that’s not even required!  The trigger button connects to pin 28.  The IR LED connects to pin 27 and the indicator LED connects to pin 26.  The mode switch goes on pin 25.  The power switch connects between the battery clip and the ground.  I actually left it off when I built the circuit on the breadboard.  If you want to add the LCD, it should be hooked up according to the instructions in the Nerdkit guidebook.

Parts List
ATMega 168	Microcontroller – comes with the Nerdkit.  Others will probably work, but I only have experience with this MCU.
LCD and resistor	I only included this to debug my code.  In the permanent project, I left the LCD off because it’s really not needed.
Potentiometer	There is one included with the Nerdkit but it must be adjusted with a screwdriver.  In the final project, I used one that I salvaged out of some old headphones.
2 x Single Pole Double Throw switches	Also included in the Nerdkit, but theirs are PERFECT for the breadboard and I didn’t want to give them up.  The two I used were the “Stereo-Mono” switches off of more headphones.
1 LED (any color)	This can be any kind, any color.  It can be left off because it just indicates when the IR LED is flashing, but I find it’s pretty useful to know when/if your intervalometer is firing.
Tactile Switch (Push button)	There is one that comes with the Nerdkit, but I used a different one that was smaller and less ugly
Crystal Oscillator	Comes with the Nerdkit.  This piece is needed to be able to count the time accurately.
0.1uF capacitor	Comes with the Nerdkit.  Used to even out the load.
Wire	Any old wire will do.
9V Battery	Gotta have juice!
9V Battery Clip	Gotta get the juice to the board!
Voltage Regulator (7805)	9V will fry your microcontroller so you gotta step it down with a regulator.  Also included in your Nerdkit.
IR LED	This is the only part I had to buy at Radio Shack.  I think I ended up spending like $1.59 on it and it came with an IR detector as well.  I used this one.
Perfboard (Optional)	This is used to make a permanent intervalometer if you so desire.  I guess you could use this one, but I found one smaller and cheaper in the store.

Here is the schematic for the circuit.  I know absolutely nothing about schematics or Cadsoft Eagle, but I made one anyway.  I hope it is of use to someone.  There are probably errors on it, please let me know if you see one.

Here’s what it looks like when it’s completed on the breadboard.

The Software
The software is the biggest program I’ve ever written (that’s not saying much).  It has a function called LED cycle that pulses the LED at 38KHz which is really important.  My first version of the program did not pulse correctly and the camera only picked up the signal VERY sporadically.  It has another function called click that spells out the pattern that your camera must see before it takes a picture.  Nikon’s pattern is kinda complex.  I got all the info on it from Big Mike.  There is a graph on that page that will tell you everything you need to know.  Emulating the pattern on the Nerdkit just took some simple math.  I also wrote a function that emulates the Canon IR remote, but I didn’t have a Canon camera to test it, so it might or might not work.
The intervalometer operates in two modes: remote and intervalometer.  I set the program up to wait for a button press.  Once you push the trigger button, it checks the mode switch.  If it is in remote, it takes a picture and waits for the next button press.  If it is in intervalometer, it polls the analog to digital convertor 100 times and averages them to find out where the potentiometer is set.  It then sets the interval accordingly and takes a picture.  Then it starts looping in a pattern of delay, snap a pic, delay, snap a pic.

You can download the source code here.

Putting together a video out of the time lapse can be done many different ways.  On Windows, you could use Windows Movie Maker or Adobe Premiere.  Mac users can use Final Cut Pro.  I put the two time lapses on this page together on my Linux laptop, so I used dvd-slideshow.  There’s a good tutorial on it here.

It’s kind of tricky getting the exposure just right to show off the sky and ground at the same time.  I’m still working on it.  This is the best time lapse I’ve gotten so far.

Noah’s kindergarten class held a program and it was a lot of fun.  It was called “A Salute to Poultry” and featured all the youngsters singing the latest Turkey Tunes.  Chris found a pilgrims costume to borrow and Noah actually wore it!  He always tells me how much he hates singing and dancing at school, but it looked like he had fun.  Myra’s teacher made a cameo as Super Turkey but the highlight of the evening was the Turkey Tango, a song with a lot of cool dance moves.

More pics are up on Flickr.

I’ve had some people ask about the particulars of the Voice Controlled LED sign from a couple days ago:

If you’re a non-geek, this probably won’t interest you.  So Mom, you can skip this post.  By the way, it got featured on the front page of the nerdkits website!

I made the LED sign following instructions from this tutorial on Nerdkits.com.  The hardware is some LED’s, a nerdkit, a piece of cardboard and a bit of wire that I got from some Cat 5 cable laying around.  I cut out the cardboard and printed a grid to help me lay out the LED’s.  I think mine were 1 cm apart.  The soldering took forever and it was the first real time I did any soldering so it looks kinda crappy.  Oh well.  It works.  The sign itself is powered by a 9 volt battery and receives data from my laptop through the serial port via a USB adapter.  All that stuff was included in the Nerdkit when I bought it.  The microcontroller is running code from the tutorial I mentioned earlier.  One of these days I’m going to make an enclosure for this thing.

On the software side of things, there are two python scripts that make everything happen.  The one called voice2led.py is a script that reads a text file and prints whatever is in it to the sign (twice, but that is easily adjustable).  I did this so that I could easily change the message by just editing the text file.  The script will print to the sign at whatever interval you choose.  Mine is set to every 60 seconds.  I have a file named led_message.txt that contains the actual message.

The other python script, named checkvoicemail.py is where all the cool stuff happens.  Using the PyGoogleVoice module of python, this script checks my Google Voice account for voicemails.  I have it set to only read the most recent message.  It parses the voicemail and checks it to see if “Message” is the first word.  If it isn’t, it sits back and waits for one that does.  This way, if I get a real voicemail, it won’t be broadcast on the sign.  As an aside, I tried a few different phrases to trigger a sign change before just settling on “Message.”  Google Voice would occasionally mess up the transcription on things like “Change Sign” and “New Message”and the message would get kicked out.  Once it finds a voicemail that begins with the trigger word, it chops off the word “Message” and then writes the rest to the led_message.txt file.  For the sign to run the way it does in the video, you need to run both python scripts at the same time.  One to check voicemails and the other to write them to the sign.  It’s that easy!

Source code available here.

This script can be easily adapted to write your latest SMS messages to the sign as well.  PyGoogleVoice has some great examples included in it that really helped me out.  I hope you enjoy playing with this stuff and if you have any suggestions for improvement, please let me know!