Twitter Updates

    follow me on Twitter
    See all our photos at

    Kirin's Electronic Project

    Since kids imitate pretty much anything you do, Kirin is now getting into electronics projects. Luckily I saved all my kits from when I was a kid, so she doesn't have to steal my current toys.

    Kirin's Birthday Song

    Kirin had her 2nd birthday in April. During her party, she joined my dad on his pans.


    Kirin discovers Bubble Wrap

    We got a package today, and it came with a bonus toy for Kirin. Bubble Wrap!


    Open Letter to Apple

    Wow, it is really hard to register a complaint with Apple. Good job hiding any ability to contact Apple behind a maze of distracting options.

    Why does Apple reject an app like nin: access for ‘objectionable’ material, when the same objectionable material is accessible through mobile Safari, or the iTunes music store? If Apple wants to continue to push the iPhone / iPod Touch platform as a true mobile computer, it must relinquish arbitrary and artificial restrictions like this. This is my device, and I will put whatever content I want to on it. Up to now I’ve been able to do that without resorting to jailbreaking. If this is no longer true, I will have to look at the alternatives.

    I’ve been a pretty happy Apple customer for decades now, but the arbitrary social restrictions Apple is imposing on this device have me very unsettled. I will not be purchasing any upgrades to this platform unless this situation changes.

    I do not need Apple to protect me from the evils of the world. Please leave that up to parents and adults.

    You cannot censor the internet.

    Mark Fischer


    Angela's Wings

    Angela finally got the shading done on her wing tattoo. 2 years later, it looks really great!

    Angela Knits a Blanket

    Angela’s first blanket came out pretty well I think!





    Putting stars on our ceiling

    Playing around with silly electronics again. This time the idea is to put twinkling stars on the ceiling of our bedroom. I’m using two TLC5940 chips to drive LEDs. The chips are capable of 16 channels of PWM, so the stars can fade on and off nicely.

    Step 1 was a proof of concept. Could I figure out how to hook up one of these chips to an Arduino, and get it to fade some LEDs on and off? Fortunately, the Arduino community is amazing, and someone has already written a fantastic library for this chip. (Thanks acleone!) The documentation on how to hook the chips up is all defined very nicely in the comments of the example programs in the library.

        Basic Pin setup:
        ARDUINO                                     TLC5940
       ------------                                 ---u----
                 13|                          OUT1 |1     28| OUT channel 0
                 12|                          OUT2 |2     27|-> GND (VPRG)
                 11|                          OUT3 |3     26|-> SIN (pin 7)
                 10|-> BLANK (pin 23)         OUT4 |4     25|-> SCLK (pin 4)
                  9|-> XLAT (pin 24)            .  |5     24|-> XLAT (pin 9)
                  8|                            .  |6     23|-> BLANK (pin 10)
                  7|-> SIN (pin 26)             .  |7     22|-> GND
                  6|                            .  |8     21|-> VCC (+5V)
                  5|                            .  |9     20|-> 2K Resistor -> GND
                  4|-> SCLK (pin 25)            .  |10    19|-> +5V (DCPRG)
                  3|-> GSCLK (pin 18)           .  |11    18|-> GSCLK (pin 3)
                  2|                            .  |12    17|-> SOUT
                  1|                            .  |13    16|-> XERR
                  0|                          OUT14|14    15| OUT channel 15
       ------------                                 --------

    Two TLC5940s on a shield

    Once I had a single chip working on a breadboard, it was time to plan out a more permanent board to house two chips.  Two chips gives me 32 stars, which I figured was enough to start with.  In order to fit the chips on the shield, I changed the transfer mode from SPI to bitbang inside of tlc_config.h, this let me just move from pins 11 and 13 over to 4 and 7, and let me squeeze in the TLCs right next to the arduino connector pins.

    I changed the suggested resistor on the chip from 2kΩ to 100kΩ.  The white LEDs I’m using are just way too bright with only 2kΩ of resistance.  100k knocks the brightness down to an acceptable level.

    Next I need to start getting serious about wiring up a bunch of LEDs and start sticking them to my ceiling.  I also have to figure out an elegant way of bringing in 30+ very thin wires and connecting them to their appropriate pins.

    Update: See how this project got finished.


    Angela's First Sock

    Angela has been working on this sock for a while. It’s really a sock! I always find it amazing how simple things are actually made.


    Kirin's Stickers

    Kirin’s cousin Katie sent her some stickers! Kirin approves.



    We went to the Tucson Zoo today with some friends. Kirin had a lot of fun looking at all the animals!


    Getting Even with Indecipherable Billing

    This is great:


    Tucson Children's Museum

    IMG_2429We went to the Tucson Children's Museum over the weekend again. Its a pretty nice place to just let the kido run wild.  She just had a great time!

    You can see more photos of the trip on flickr.


    Arduino Rangefinder 

    I’ve always been a programmer. However, the world of hardware has always intrigued me. I’ve always been somewhat interested in the ability for electronics to actually *do* something in the real world, and not just push pixels around a screen.

    I first heard about the Arduino micro-controller world on an episode of MacBreak Weekly. Andy Ihnatko was talking about it for an upcoming talk he was giving. Basically the Arduino is an open-source micro-controller. It connects to your PC via a USB port. There’s a custom IDE built for it that runs on Macs, Windows and Linux. The basic idea is that you can now easily control simple voltages on pins. Connect them to sensors, motors, LEDs etc, and control the real world from a very easily accessible starting point.

    So I finally got around to ordering the standard Arduino board, some sensors, a breadboard, and started playing.

    An interesting concept with the Arduino world, is the idea of a ‘shield’. Basically a shield is a board that fits on top of the base Arduino, and adds some functionality to the basic setup. A proto-shield is just a shield that gives you a small space for prototyping. The SparkFun shield also gives you a couple of LEDs with resistors in place, and some switches to play with.

    The proto-shield comes as a kit, so I got to practice my soldering skills. I had never really soldered on a board before, but after a few minutes of poking around, I eventually got the hang of it. Shield assembled, I was amazed at how fast and easy it was to start getting readings from the ultrasonic sensor. The following few lines of code were all that was needed to read the sensor value, and send it to a listening serial port:

    int sensorValue = 0;
    int sensorPin = 1;

    void setup() {

    void loop() {
      sensorValue = analogRead(sensorPin);

    The input / output pins on the Arduino board are all numbered, so you just pick a pin, hook up your sensors, and you’re off!

    Once I figured out how to get reliable readings from the sensor, I figured a simple thing to build would be a system to see if I was at my desk or not.

    I pulled the parts off the protoshield, and built a more permanent set of boxes. One box for the Arduino, and another for the sensor. This let me position the sensor in an appropriate spot, and allowed me to plug the Arduino box into a USB port.


    Arduino House & Buttons

    Sensor Box

    Assembled Boxes

    The two buttons let me set the range at which the sensor will trigger an “Away” or “Here” message back to the computer. A simple program running on my mac then picks up the signal from the Arduino, and relays it to a web service that then tracks my presence.

    Parts List:

    Arduino Duemilanove
    Maxbotix LV-EZ1 Ultrasonic Range Finder
    Arduino ProtoShield Kit


    ProximitySensor v5


    Kirin's Activity Board

    Kirin’s been interested in widgets lately. Knobs, handles, light switches etc. Instead of continually shooing her away from them, we figured we’d make some just for her.



    Music Lessons Begin

    Originally uploaded by estranged42


    Well, she’s 15 months old now, so we figured it was time to begin music lessons.