Nuts and Volts - September 2008

by Joe Pardue

PART 2: Your First AVR Program

C’ing With Cylon Eyes

Get started now with this series! Joe’s book & kit are available in our webstore at

www.nutsvolts.com

This workshop is the second of a series that will introduce C programming for the AVR microcontroller based on the book C Programming for Microcontrollers Lby Joe Pardue available from www.smileymicros.com ast month, we learned where to get the software and hardware we’ll need, built the ^or^Nuts ^& ^Volts ⁽^{www.nutsvolts.com}⁾^.

AVR Butterfly-based AVR Learning Platform, and tested it with Developer Terminal. This month, we will write and compile our first C program using our AVR

Learning Platform. This is not

^■^FIGURE ^1. ^Cylon.going to be the standard wimpy ‘Hello World!” of yore, but a zippy software/hardware combination where we create some Cylon eyes. These _aren’t _eyes _of _the _cute, _sexy■ FIGURE 3. Welcome to AVR Studio 4.

Cylons of the recent Battlestar

Galactica, but the old fashioned ‘70s walking chrome toaster Cylons of the original series.

Setting Up the Project Configuration Options

From the ‘Project’ menu item, select ‘Configuration Options’ (Figure 5).

In the ‘Project Options’ window, select the ATmega169 from the ‘Device:’ dropdown box (Figure 6).

Getting Started With Free Stuff: AVR Studio and WinAVR

AVR Studio provides an IDE for writing, debugging, and simulating programs. We will use the WinAVR GCC C compiler toolset with AVR Studio via a plug-in module.

You can find these at AVRStudio ( http://atmel.com/ dyn/products/ tools_card.asp?tool_id=2725) or WinAVR ( http://sourceforge.net/projects/winavr/).

Install WinAVR first and AVR Studio second (use the default locations so AVRStudio can find WinAVR).

Click on the AVR Studio desktop icon (Figure 2). It opens with ‘Welcome to AVR Studio 4’ (Figure 3). Click on the ‘New Project’ button.

In the ‘Create new project’ window

(Figure 4), click on AVR GCC, add the

‘Project name’: ‘CylonEyes,’ and set the

‘Location’ to a convenient spot. Then click finish.

The IDE is somewhat complex, with lots of tools that we won’t be using just yet, so try not to have heart palpitations. It will mostly make sense eventually.