This might sound silly but when u start a microcontroller project how do u decide which micro controller to use
pic/atmel,
8bit/16 bit,
code in avr or c????
I/O pins etc
For a project how do u decide if the microcontroller is needed or microprocessor??
for eg an attendance system for a college ??
Please help

 

Search this forum for threads on avr versus pic. There is a lot of good information on the various pros and cons of each as well as links to helpful websites dedicated to the two micros.

hgmjr

 

It depends upon the application (if you need analog I/O and how many, how many digital I/O, the speed you need the various signals to be processed etc).

About the programming language choose the one you are familiar too.Nowadays, most uCs can be programmed in many languages. One reason to move to assembly language is if you run out of memory and you want to optimize the code to be as less as possible. But, as a newbie, as i understand you dont really need to care about this now.

The choose between AVR or PIC is not such a big deal because both families offer many functions on their chips. One thing that may be of interest to you is the fact that Atmel (AVR) offers all the necessary software for free online whereas Microchip (PIC) does not.

Another, thing to consider is which uCs your programmer is capable of programming.

 

Thanks mike u were very helpful
how do u calculate the speed of operation as such
eg :canon says it can print 200ppm
for my system how do i calculate how many cards can be read at a time ?
do i have to do it by hit and trial method??

 

It depends upon the code in the program, if its clever built and so on. In datasheets they say the approximate processing time for some functions.

 

A microprocessor includes just the program counter, instruction fetch and decode, and the arithmetic/logic unit. You have to add memory and I/O ports before you can run even the simplest program. A microcontroller incorporates some memory and I/O ports on the IC along with the microprocessor. Nowadays, you can get almost any microprocessor architecture of less than Pentium class in a microcontroller.

For a newby project, you definitely want a microcontroller. I'd recommend an 8-bit IC with both RAM (data memory) and Flash (eraseable program memory) on the IC, programmed by a cheap serial interface. Unless you need something unusual in peripherals, you won't need to bring the address and data bus out, which avoids a whole lot of trouble in getting a board to boot up in the first place. Do make sure you get debugging capability through that serial programming port, because otherwise you're sticking your code into a black box and wondering why it didn't work.

Figure out what you need in I/O functions and memory. Then double the memory and add a few more I/O pins, because unexpected requirements will arise.