Computers, including the Arduino, tend to be highly data agnostic. At their core, the heart of the device is an arithmetic-logic unit, which performs (fairly) simple operations on locations in memory: R1+R2, R3*R7, R4&R5, etc. The ALU doesn’t care what that data represents to a user, be it text, integer values, floating point values, or even part of the program code. All of the context for these operations comes from the compiler, and the directions for the context get to the compiler from the user. You, the programmer, tell the compiler that THIS value is an integer and that value is a floating point number. The compiler, then, is left trying to figure out what I mean when I say “add this integer to that floating point." Sometimes that’s easy, but sometimes it’s not. And sometimes it SEEMS like it SHOULD be easy, but it turns out to yield results you might not anticipate.
Tuesday, August 28, 2012
Saturday, August 25, 2012
The 555 timer IC is often considered one of the most successful integrated circuits of all time. That success stems not only from its sheer production volume — with approximately a billion made annually — but also for its ease of understanding and the diversity of its applications. Over at Weekend Projects, we’ve used the 555 in everything ranging from beginner-friendly breadboard experiments to advanced weekend-long builds. Continue reading after the jump for some fine examples of the 555 in action.