Nuts and Volts - August 2008

programmable, and development software can be had for FREE (really free, not crippled or limited in any way). I’ve paid thousands of dollars for development boards, programming devices, and C compilers for the other micros, but never again — I like free. The hardware used in these workshops — the Atmel AVR Butterfly — can be modified with a few components to turn it into a decent learning system and the needed components can be had for less than $40. You can’t get a better learning system for 10 times this price and you can pay 100 times this and not get as good.

You will often stumble across arguments on the Internet as to which microcontroller or programming language is the ‘best.’ People take sides and soon a religious war breaks out. I don’t want to enter that fray, so I’ll just say that the AVR is the best microcontroller and C is the best programming language and if you don’t believe me, you are bound for perdition —

hallelujah and amen. (Agreed! -Ed.)

kind of a jet plane ride over the territory.

Workshop Goals

What I hope to accomplish with this series is to help you learn SOME C programming on A SPECIFIC microcontroller and provide you with enough foundation knowledge that you can go off on your own somewhat prepared to tackle the many kinds of microcontrollers and C programming systems that infest the planet.

Both C programming and microcontrollers are best learned while doing projects. I’ve tried to provide projects that enhance the learning process, but I’ve got to admit that some of the projects are pretty lame and are put in mainly to help you learn C syntax and methods.

I know how easy it is to get bogged down in all the detail and lose momentum on this journey, so we’ll begin with a quick start guide and learn just enough to get our learning platform tools working —

Quick Start Guide for the AVR Learning Platform

■ FIGURE 2. Developer Terminal.

Software

AVR Studio — FREE and darn well worth it.

AVR Studio is provided free by the good folks at Atmel Corporation, who seem to understand that the more helpful free stuff they give developers, the more they will sell their microcontrollers. Actually, this software could cost hundreds and still be darn well worth it, but unless you just really like Norway, don’t send them any money; they’ll get theirs on the backend when you start buying thousands of AVRs for your next great invention. The workshop is based on version 4. 14 and if you use a newer version you may find differences in it and our discussions. You can find AVRStudio at www.atmel.com under the AVR Tools & Software section: http:// atmel.com/dyn/products/tools_card. asp?tool_id=2725).

WinAVR — Oh, Whenever ...

WinAVR is a GCC compiler toolset for Windows that we will use in AVR Studio. We will use this package under the AVR Studio IDE that has a GCC plug-in that finds the WinAVR installation and adapts it to the IDE. You can find WinAVR at:

http://sourceforge.net/projects/ winavr/.

Developer Terminal

Figure 2 shows the PC terminal we will use to communicate with the AVR in our workshop. You can get the terminal installer and related documents from www.smiley micros.com. The source code in C# and Visual Basic .NET for this terminal is discussed in detail in the book Virtual Serial Port Cookbook (by me) and is available from www.smileymicros.com and