Before we get into the meat of today's post, I want to announce the winner of last week's caption contest. Here goes nothing...

alt text

Go home, Dave. You're drunk.

Congrats, jdavidbush! You're the proud owner of a Sphero. Keep an eye on your email for further instructions! Now, on to today's post - "Engineering Roundtable." Today, Joel will talk about his "critter cam" and his automated terrarium.

Vimeo version can be found here.

If you want more information of creating the controllable outlet in the second half of the video, check out this tutorial. Here's a fairly complete list of the parts used in the "critter cam":

Joel uses this Easy Cap Viewer software.

For the automated terrarium, Joel used the following:

For more videos of the terrarium in action, check out Joel's YouTube channel. You can find the code Joel used for the terrarium here and for the critter cam here. As always, feel free to leave any questions or comments below. Hope you enjoyed this edition of "Engineering Roundtable."

Comments 17 comments

  • jdavidbush / about 11 years ago / 1

    I don't know where to send a thank you, so I'll just leave this here... THANK YOU for the Sphero!

  • Member #385330 / about 11 years ago / 1

    Hi Joel! Enjoyed watching the various steps of the projects. I am however curious on a biological level about the influence or IR, servo noises as well as the UV source on your captives. Are the tarentula and emperor scorpion sensitive to noises and radiation outside our visible spectrum? I know UV sources are used to attract mosquitoes in HV traps. Just wondering...

    Is there a Spark Fun pdf catalog that would allow me to research your products off line?

    Just found Spark Fun, and I love it already!

    Robert St-Marseille Montreal

    • Joel_E_B / about 11 years ago / 1

      Hi Robert,

      Glad you enjoyed the video and enjoy what we do here at SparkFun. That is an excellent question, and one I have asked myself many times. From what I have read and as far as I can tell, the IR and UV light spectrum don't affect the tarantulas or scorpions. When I observe the scorps under UV light they don't seem to be bothered by this, as they go about what they were doing. However, if I'm moving about in the daylight, they can sense motion and often retreat into their burrow. Also, the nightvision camera is pointed directly into his burrow most of the time, and he sits there at the entrance and doesn't seem to be bothered by it. The IP camera has a photoresistor to tell whether it's light or dark, so the IR LEDs aren't on all the time, but when they are, he still hangs out at the entrance. That said, neither species has very good sight or hearing. Both rely more on vibration to sense the world around them. They're tiny little eyes can't see much of anything besides movement, and whether they can hear anything or not is still somewhat of a mystery. However, they can sense vibration very well because of the little hairs (which are different than human hair) that surround their bodies.

      As far as our catalog, we used to have a downloadable pdf, I can't find the link, so it may need updated. I'll post the link here if I come across it. Thanks for your inquiry.

      • Member #385330 / about 11 years ago / 1

        What about the subsonic AND audible vibrations? Could their cillia sense these and cause them to respond in a stressed manner?

        Can a watched kettle boil?

        Thank you

        Eisenberg and me Robert St-Marseille, Montreal

        • Joel_E_B / about 11 years ago / 1

          Watching water boil is just like watching the clock, always seems to take longer. I can't say for sure whether the electronics have that effect or not. I've spent many hours watching my critters, with and without the aid of IR or UV light. I'm not that experienced at studying living things, but I do have a knack for observation. If they do get stressed by the presence of light or vibrations from my devices, I have not noticed it. Even when I move the camera in their presence, they don't seem to take notice and go right on doing what they were doing. You seem pretty knowledgeable in entomology (sorry if my first response seem to talk down). I'd love to hear your opinion on on whether or not it would stress them.

          Also, I discovered our marketing team is revising the PDF version of our catalog. Hopefully, it should be back on the site soon. Thanks.

          • Member #385330 / about 11 years ago / 1

            Sorry that the very limited vocabulary I have caused you to think I know more than you do about the beasties, I was curious is all. In fact, I am a teacher and designer of hadware and software solutions to communication, instrumentation and control equipments who dabbles in video and mechanical gizmos when I have the time. People say of me, that my worst fault is also my best asset, namely insanely unsatiable curiosity! They sometimes call me sponge bob squarehead!

            Since both your pets live on and under the ground, I understand that they rely on soil vibration to warn them of both danger and approaching preys.

            This led me to the question about the servo's vibration triggering a defense reflex in either of them.

            I do have a tendency to come up with tangential questions when exposed to new subject material, that is my curiousity reflex trigger!

            Thank you again for taking the time to answer my query and keep experimenting and being curious about what causes your trigger to ask what if?


            Robert St-Marseille Montreal, Qc, Canada

  • Joel_Q / about 11 years ago * / 1

    Typo: it’s retired by you can -----Should be: it’s retired *but you can

  • Aptex / about 11 years ago / 1

    Does anyone know how he would have programmed the terminal program to control the camera?

    • Joel_E_B / about 11 years ago * / 1

      There is no programming of the terminal. It is simply displaying what the Arduino was programmed to print out and read in via the UART. The only setting you have to alter on the terminal is the baudrate. If you take a look at the Arduino sketch, you'll see that the Arduino is just reading the serial line. If it sees a characters, such as 'w', it moves the servos accordingly.

  • EdZilla / about 11 years ago / 1


  • Darn.....I really wanted that sphero!

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