Tuesday, February 28, 2012

Shifing a bit. Lots of bits.

Well since I am out of instrument type op amps, I went ahead and dug out my shift registers.  I got it working.. after finding out you need to power all the power lines. 

Here's the instructable I refrenced when I ordered the shift registers: http://www.instructables.com/id/The-74HC164-Shift-Register-and-your-Arduino/

I'm going to need to give this another swing soon.  

Testing sensors.

Well I bought some pressure sensors.  In hopes of building my own altimeter.  When motorola says 5-25mv output, they aren't kidding.  The mpx2010 has an output that seems perfectly tuned to feed an opamp.  Time to learn opamps.

Here's a link to the datasheet: MPX2010

Wednesday, February 22, 2012

Fixing a samsung tv. Blown something or other.

At my work we have som tvs for status of the network.  Friday, when my coworker was turning one on, there was a loud pop.  And then the tv didn't work. 
Well, these tvs tend to blow caps, and that's what I assumed the problem was.   well, it was something polyester filled....  time to order a replacement.

Replacing that cap did bring the TV back to life.

Tuesday, February 14, 2012

Small time failures: the nano upgrade that didn't.

Well, the tires are tiny, and really tight.  So, I decided they aren't staying.  They are also heavier than I hoped.  The saddle is much nicer than the vader saddle. 

The new seatpost and spacer look good.  I think I like the yellow saddle. 

More mercier nano bits.

You'd think a nano would take smaller parts... but these tires are a full 406mm bcd.

They say folding, but they aren't.  They're for folding bikes, but have wire beads.  Bummer...

Playing with digital glue: using an arduino as a really expensive voltmeter.

Last Thursday I met up with Loclhst to show him how to use analog sensors with his arduino. 

The process started with testing the photoresistor and thermistor on the bench with a voltmeter.  We then set them up in a voltage divider, and fed 5v across them.  That got us a voltage output we could send to the arduino. 

Then we hooked up the voltage dividers to the arduino, and we got real values. 

Then dan wanted to get his display working.   After we discovered I had a wire crossed, the display worked fine.

Wednesday, February 1, 2012