Archive for December, 2010

Engineers Need to Save the World, But It’s Hard to Sell

Monday, December 27th, 2010

G. Pascal Zachary says, in his article for IEEE Spectrum Magazine, Why Engineers Must Try to Save the World, that engineers need to work to save the world.

It may be selling engineering short to call the desire to save the world  “messianic”.  The end of the article focuses on geoengineering approaches to climate change.  The article discusses debate within the UN about whether we should not study geoengineering approaches to climate change or we should proceed in case the planet is “broken beyond conventional means of repair”.  It’s questionable to call a complex system like our planet “broken” or fixed”.  There certainly are no conventional means of repairing a planet.

The climate of the earth is changing because of natural processes (i.e. moving deeper into a glacial minimum period) and because of human activities.  Critics of geo-engineering want an approach based on carbon emission reduction and increasing natural CO2 absorption.  I support those measures, but I suspect they will be insufficient.  Even if we stopped all carbon emissions, we would still face rising sea levels due to the natural receding of the glaciers.  The goal should not be a planet just as it would be if humans were not present but a planet that serves human needs.  Engineers need to be a part of that.  The fact that climate change is happening faster because of human activities only increases the urgency to develop geo-engineering techniques.

This research will be hard to promote because the loudest voices in the environmental debate either want a) to preserve a climate free from anthropogenic effects for the sake of nature itself or b) to deny blissfully that the climate is changing and human activities can shape how it changes.

The problem of sound engineering approaches being tough to sell crops up in other issues.  Engineers should work on promoting engineering-style solutions to the world’s big problems.

Good Results Using MSO-19 USB Scope for SPI

Tuesday, December 14th, 2010

A client was having trouble initializing an SD Card in SPI mode.  They had a nice Agilent scope to look at the signals.  I could put it in single-trigger mode with a slow sweep rate and then turn up the sweep rate (reduce μs per division), effectively zooming out.  Then I could look at the data lines at every clock edge, write down the bits, translate to HEX, and work out what commands and arguments were being sent.

I purchased a $250 MSO-19 USB scope and had good results with it.  As long as a I set a reasonable sweep rate, the SPI decode feature would automatically turn the signals into HEX for me.

Pros:

  • Automatically transcribes input and output data to HEX
  • You can trigger on certain bit sequences or on any input’s rising/falling edge.  This makes it easier to isolate the area where you want to read the data.
  • Easy to send screenshots to colleagues
  • $250

Cons:

  • There was some flakiness that temporarily prevented it from decoding the SPI data.  I had to restart the software and change the sweep rate to get it going again.
  • If you set the sweep rate too low, it won’t be able to read the data.  If you set the sweep rate too fast you won’t get much data, and you cannot scroll.

This was my first time using a USB scope.  The software interface is a little too difficult and sometimes flaky for it to replace a traditional scope.  I am definitely keeping it, though, for its portability data decoding ability.