I haven't tried it out yet but I've stumbled across an AVR microcontroller IDE for Linux. It's called KontrollerLab and looks promising. When I searched around about a year ago I couldn't find anything and have often considered starting a project myself. But I like what I'm seeing here. It's called KontrollerLab.
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If you a home hobbiest such as myself, having an oscilloscope is ideal, but may not be economically feasible. However, there is a free option available. xoscope For Linux is a GTK application which allows you to view signals through your PC's sound card (thus limiting the range to audio frequencies dependent upon the sound card being used). This can come in handy for robotics type hobby projects. Additionally, the author (Tim Witham) has provided a buffer hardware circuit to buffer the proble similar to a true oscillosope and protect your PC's Line In from excessive voltages.
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| FailureBot 5 - Complete Robot | FailureBot 5 Following A Line |
Though an input can be from any number of sources, one of the mose common and the easiest to implement, would be a swith. Due to mechanical properties of a switch, when a switch is closed, there is a period of time in which the electrical connection "bounces" between open and closed. To a microcontroller, this "bouncing" can be interpreted as multiple button pushes. Therefore, we must either build a circuit to supress the "bouncing" or we must do so in our software. This is known as "debouncing a switch".
The ATMega8 AVR is shipped with it's clock source configured to the internal 1MHz RC oscillator (see: "Calibrated Internal RC Oscillator" in the datasheet p.30). This configuration works fine for many small projects where timing isn't crucial and is also convenient as it reduces parts count (1 crystal and 2 capacitors). However, you may run in to situations where you need a more accurate clock source.
The AVR family of 8-bit microcontrollers from Atmel are quickly growing in popularity for electronics and robotics hobbiests. Their major selling point for me, as opposed to the PIC microcontrollers from Microchip, are their being designed to be developed using higher languages such as C. This allows them to be developed using the open-source GNU tools (gcc). This works out especially well for me working in Linux.
Sharp's GP2D120 (and the GP2D12) is an infared distance sensor which is pretty common in the hobby robotics community. I purshaces a couple of these from DigiKey to use in a small wall-huggin robot. I spent quite a bit of time experimenting with it. This page will provide you with my schematic and AVR gcc source code for my demo file. It simply uses the ADC on an ATMega8 mpu to read the analog output of the GP2D120 and send the distance in centimeters to my laptop through the serial port (actually, through a USB to serial converter).
I purchased a Powertip PC-1202A 12x2 LCD with backlight from Wright Hobbies a while back since it was only $7.95. I will be using it often for various projects with robotics and microcontrollers. The problem was, I didn't want to take up all my IO pins on my processor just with the LCD interfacing. I found some circuits for 3-wire and 2-wire interfaces. I went with the 3-wire interface (4 if you want the AVR to control the backlight) and wrote my own little set of routines for controlling the LCD.
I just purchased my AvrUsb500 from tuxgraphics.org. The AvrUsb500 is an open-source (hardware and software) USB programmer for the Atmel AVR microcontrollers. This is just a quick run-down on how to get setup using the AvrUsb500 on a Linux system. In this case, I'm using Fedora Core 4. It is assumed that you have setup your Linux distribution with the GNU tools for AVRs (avr-gcc). If you haven't, you should first read Installing the GNU tools for AVRs.
This is just a quick, simple little program for an ATMega8 (can easily be adapted to any AVR) that I've setup to test the installation of avr-gcc and the GNU toolchain, avrdude, and my AvrUsb500 USB programmer from tuxgraphics.org.
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