AVR and ATmega both in the Atmel

PA3040 said:

what is the most recommended demo boar for beginners that i need to purchase. I hope to start with Atmega 32 MCU

Click to expand...

ATmega32 is a very popular AVR. Most likely because it is an old AVR in the market for years.
AVRs do not really have much difference with each other. If you learn to use one of them, then you will easilly use another one.
In my opinion, the "most recommended board" has nothing to do with the AVR on it, but with all the others board peripherals. As many peripherals the board has (memories, LCD etc), the better is for you because you will have more things to work with and learn.

Dear alex,
Thank you very much for reply and advice
Actually I could not need to develop application at this stage, mainly I need understand the operation of features like Timers ADC PWM (ccp)
I2c ect, and test them using demo board. for this purpose what is the most good board that I can buy from atmel site
Thanks in advance

PA3040 said:

Actually I could not need to develop application at this stage, mainly I need understand the operation of features like Timers ADC PWM (ccp)
I2c ect, and test them using demo board. for this purpose what is the most good board that I can buy from atmel site

Click to expand...

As with many things in this field, a viable recommendation depend largely on availability and locale.

Where are you located?

BigDog

Dear bigdog,
Thank you very much for reply
I am In Asia pacific Reagan, Colombo SriLanka
Please help

Can you purchase items off of ebay?

If you want a flexible development board which supports a wide range of AVRs and pin counts keep a lookout for a used original STK500.

Atmel STK500 (ATSTK500)

I have two STK500s which I still use for development purposes, which I purchased used for $30 to $35 on ebay. The STK500 has a built-programmer which used a standard PC serial port. It can also support both the AT89S52 and AT89S51 as well.

If you want a lot of bells and whistles, Atmel, believe it or not, sells a very inexpensive development board with one of the larger AVRs and several peripheral devices:

Atmel MEGA-1284P Xplained (ATMEGA1284P-XPLD)

At $29 it is hard to beat. In my opinion, it is a very good board for educational purposes, but limited for commercial development.

If you cannot or do not wish to purchase it directly from Atmel, I believe Element14 (Newark) carries the board and ships to your area.

I'll see what other recommendation I can come up with.

BigDog

Dear Bigdog
Thanks for advice

Can you purchase items off of ebay?

Click to expand...

yes we can with paypal
Thanks

PA3040 said:

yes we can with paypal

Click to expand...

I personally buy quite a few development boards off of ebay. I usually only purchase genuine manufacture boards, for example Atmel's STK500, STK600 and various add-ons Atmel manufactures and sells.

Be careful of the cheap clone manufactures, you often get what you pay for.

An inexpensive Chinese company which I have purchased quite a few ARM development boards, although no Atmel boards:

WayEngineer AVR Development Boards

I've never had any bad experiences with WayEngineer, however as usual their documentation and technical support is limited as with most Chinese companies.

BigDog

Dear All

what is the most recommended demo boar for beginners that i need to purchase. I hope to start with Atmega 32 MCU

Thanks in advance

Click to expand...

If you mean on development board, best is from Mikroelektronika https://www.mikroe.com/eng/categories/view/9/avr-development-tools/

Dear All
I sow in Atmega32 datasheet in the Block Diagram of the AVR MCU Architecture, SRAM used as Stack, but PIC 16f877a has only 8levels stack separate from data memory, but in AVR it's capacity upto SRAM capacity ,Am I correct?

Yes, you are correct.

Reference: ATMEGA32 Datasheet

During interrupts and subroutine calls, the return address Program Counter (PC) is stored on the
Stack. The Stack is effectively allocated in the general data SRAM, and consequently the Stack
size is only limited by the total SRAM size and the usage of the SRAM. All user programs must
initialize the SP in the reset routine (before subroutines or interrupts are executed). The Stack
Pointer SP is read/write accessible in the I/O space. The data SRAM can easily be accessed
through the five different addressing modes supported in the AVR architecture.

Click to expand...

Reference: PIC16F877A Datasheet, Section 2.3.2 STACK

2.3.2 STACK
The PIC16F87XA family has an 8-level deep x 13-bit
wide hardware stack. The stack space is not part of
either program or data space and the stack pointer is not
readable or writable. The PC is PUSHed onto the stack
when a CALL instruction is executed, or an interrupt
causes a branch. The stack is POP’ed in the event of a
RETURN, RETLW or a RETFIE instruction execution.
PCLATH is not affected by a PUSH or POP operation.
The stack operates as a circular buffer. This means that
after the stack has been PUSHed eight times, the ninth
push overwrites the value that was stored from the first
push. The tenth push overwrites the second push (and
so on).

Click to expand...

Although, I will have to say, while I continue to use both 8-bit Atmel and Microchip MCUs in my commercial projects, it has rarely if ever been an issue.

As a matter of fact, I find the a stack of set depth helps enforce good coding techniques for embedded systems, while minimizing the use of recursive functions, etc, which can quick consume both a stack of set depth and and one allowed to grow, as in a sense they are both limited to a degree.

Remember the SRAM of the ATMEL devices is also used to store the codes variables.

BigDog