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Customer Testimonials » Got my NerdKit going!

December 11, 2010
by mbobak
mbobak's Avatar

Hi all,

Nerdkit arrived yesterday. I've got comments and questions.

First, got the initial build done. Not the temp sensor yet, that's next. I got the initial wire up of the board, the LCD, etc, and got the "Welcome" message. (Small victory! :-))

Initially, I had a problem. Plug in battery, no joy. So, I doubled checked all the wiring. It looked ok. I came to the conclusion that I'd either chosen the wrong resistor or wrong capacitor. So, I pulled them both off to take a closer look. Dug up a magnifying glass, to make sure I can see what's on the resistor. Sure enough, wrong resistor! So, I put the correct resistor in, and, Bingo!, I get the Welcome message! It's at this point, that I realized I'd forgotten to put the capacitor back in! And the system seems to work fine without it?

My speculation as to why it works without the capacitor (forgive me if my terminology is a mess. I'm a software guy, trying to learn a bit about electronics):
From what I read, the capacitor, in this case, is there to "smooth out" the spikes in current required by the "spiky" nature of the microcontroller, which has surges in demand at the start of every clock cycle. The capacitor "saves up" some current when the microcontroller demands are low, between clock cycles, and provides that little extra kick when needed.

So, if I got the above right, then I speculate the only reason it's working without the capacitor, is that the battery is brand new, and can handle the "spikes" in demand, but it's possible that, without the capacitor, even a small drop in battery performance could cause the microcontroller to become unstable in it's behavior? Does that make any sense? Is that line of thinking correct?

Also, speaking of capacitors, I have three capacitors that look like the one pictured in the guide, and they appear to be identical. Physically, they are the same size, I can't see any difference between them. I got my magnifying glass out, and they still look identical to me! I think I'm in serious need of glasses, because, even w/ the magnifying glass, I still can't read the print on the capacitors.

Ok, on to bigger and better! Time to try the temp sensor!

So far, I'm pleased overall. I have to say, I have to get better at cutting wires to the correct length. I seem to grossly overestimate the wire length I need, and while my kit still seems to work, it does not at all resemble the kit pictured in the guide. Mine is more like a tangled, snarled mess! I suppose that will come with practice. :-)

-Mark

December 11, 2010
by nanaeem
nanaeem's Avatar

Hi mbobak,

I can relate to what you are going through. I too am a software guy just starting on the hardware side. I went through the nerdkit guide last month. Its awesome!!

Did you get a wire stripper for cutting wires. I found that once I started using the wire stripper I was cutting more appropriate lengths and must faster. I bought mine from RadioShack for less than 5 bucks.

As for reading the values on the capacitor... sigh... i have the same problem. I dont know how ppl read those tiny numbers. Though i was able to find which one was the 0.1uF capactior because I knew what i was looking for I have no idea what the other capacitor values are. If anyone knows how to read these things I would love to know.

Ordered the LED array kit a few days ago and cant wait to get started on my next project :)

-N.

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