WHY AVR...???

Why AVR...???

AVR microcontrollers are popular because of their Linux support and their softwares like AVRGCC and AVRDUDE. If you start learning with any microcontroller the cost you have to pay is the microcontroller cost+software+programmer. If you compute this then AVR is the best. Atmega8 is available with Rs.75 and programmer cost is just a printer cable costs Rs.40 with some wires and AVRGCC for Linux and WinaVR2006 for Windows.It has facilities like inbuilt ADC which is not there in 8051, which will be advantageous for robotics. Software are easily available for other microcontrollers but they have a limit of maximum 2K program memory. The project 'embedded ethernet' have around 10K program memory usage while WinAVR have no such limitations. The programmer cost of 8051 and pic are above Rs.400(as far as I know). See performance comparsion of AVR with different microcontrollers
http://www.electricstuff.co.uk/picvsavr.html
http://www.freertos.org/PC/

Here I am going to talk about microcontroller just like a computer running on parallel port and a C program. I am using the same examples. Basic thing you have to know how to program the chip and writing programms for the chip. If you know 8085 then it will be easy to understand. Anyway I am writing codes in C so that it will be easy to understand.

Softwares Required:
WinAVR2006,AVRDUDE(if you are using AVRStudio)www.winavr.sourceforge.net
atmega32,atmega8 datasheet(see in atmel.com)http://www.atmel.com/dyn/resources/prod_documents/doc2503.pdf You better make logins in www.avrfreaks.net so that when you have doubt, you can
put it there.

Hardwares Required:
atmega32 or atmega 8 (atmega32 costs from Rs.200 to Rs.350 and atmega8 from Rs.75
to Rs.120)
Breadboard
Printer Port cable
Serial port cable
Crystal(3.6864Mhz)

Difference between atmega32 and atmega32L:
Both are same only difference in frequency and voltage limitations. I prefer atmega32L
because of its low cost and easy availability. Atmega16 also serve same purpose except
its Flash is 16KB(sufficient) and difference in memory capacities. The remaining
hardware portion are same for both.