It's About Time

555

A long time ago, I told a friend that I was starting to move more deeply into the field of modeling and simulation. The friend said to me "It's about time." How true. For no particular reason other than it being January 1st, I thought it appropriate to celebrate the 555 timer integrated circuit (IC), which was designed in 1971 by Hans Camenzind. This is one heavily-used IC, and it can be purchased well under one US dollar depending on the source. The above picture is called a block diagram -- which is a high level design description of how the IC functions. If you looked inside, you'd find mostly transistors with resistors and a couple of diodes. Think of the 555 as something that can create a well-timed oscillating square wave, or just a "one shot" pulse of a given width. An egg timer, but more precise. Having just sung the praises of this IC, we also need to put this technology into context with regard to time management. The most accurate time is kept by atomic clocks, such as those employing cesium. In the semiconductor world, there is also a tug of war, sort of, between MEMS-based oscillators (oscillators built into the silicon) and quartz (which you may have seen on an Arduino or other similar micro controller). All of these technologies are "about time." With the Internet of Things (IoT), computers built around micro controller chips are getting much smaller, more powerful, and are cheaper (although not yet at the < $1 level). For example, you can make your own bare bones Arduino for about $4. You can program a 555's behavior in software rather than through voltage dividers and a capacitor. What will 2015 bring us? There is no time like the present.