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[on:]

Hi!
I've been looking at the atmega1284 chip the past few weeks, and I think it's a great chip if you need a LOT of flash memory, and more IO ports. The only problem is that the AVR it selves costs about 17$ with shipping from ebay. that's about the price of a Mega2560 (clone).
Since I don't need that much flash memory, I started looking for other, cheaper alternatives. the difference between 1284 and 644 when it comes to price isn't big. just a few dollars (at ebay). still, the smaller Atmega32A costs about 4$, and also have a lot of IO pins.

does it exist an Arduino bootloader for the Atmega32A? is there a cheaper place to buy AVRs than ebay?

Thanks!

[Reply #1 on:]

I've bought an Atmega32A from Farnell in the UK.  It cost me about £4.  I have it on a breadboard and bootloaded it with an Arduino Uno.  It works fine apart from digitalRead not working for some reason.

These links should help you get going with the bootloader.

http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=101227
 
http://retrointerfacing.com/?p=30

[Reply #2 on:]

http://www.newark.com/atmel/atmega1284p-pu/ic-8bit-mcu-avr-mega-20mhz-44-pdip/dp/68T2560?Ntt=68T2560

$7 doesn't seem that bad for an Atmega1284P. Its £3.80 here in the UK.

[Reply #3 on:]

does it exist an Arduino bootloader for the Atmega32A?

Why on earth would you want a bootloader if you're building a standalone device?

Get a $10 ISP programmer.

[Reply #4 on:]

Ebay is not always the best place to buy from.
I don't know why ATMega1284 is so expensive on ebay.

I recommend Futurlec, I have bought microcontrollers from them a couple of times.
ATMega1284  6.9$
ATMega328   2.20$
ATTiny85      1.15$

I think 6.9$ is a bit expensive compared to ATMega328.
I also recommend buying a separat programmer and skip the bootloader.

/Olof

[Reply #5 on:]

But if i'm going standalone, without a bootloader, can I still use the arduino IDE, but just program with an ISP instead, like USBasp?

[Reply #6 on:]

Yes, in the IDE you choose "Upload using programmer" from the file meny.

[Reply #7 on:]

But I still need some lines in the boards.txt file? how would the ISP be able to recognize the AVR without knowing clock freq. and fuses+

[Reply #8 on:]

Yes you still need to configure the IDE for your MCU.

I have tested Atmega1284P, Atmega8 and Attiny85 with my usbtiny programmer.

Manicabugs core worked fine for the 1284P: http://maniacbug.wordpress.com/2011/11/27/arduino-on-atmega1284p-4/

Some info about Atmega32.
http://blog.achuwilson.in/2011/12/arduino-ide-for-programming-atmega.html

[Reply #9 on:]

http://no.farnell.com/atmel/atmega1284-pu/mcu-8bit-avr-128k-flash-40pdip/dp/1972067

About $6.50, plus shipping...

eBay is weird for electronics parts.  There are some bargains.  And there are some sellers that look like they're buying at full list price and selling at double that, just to rip off the people who think that they can't buy from regular distributors...