arduino Additional memory

hi,I'm looking for additional memory ebaut 1mb minimum Can you help me

What do you want this memory for?

You can add paged memory to any Arduino but that is not memory that can be used for normal program memory.

The only way you can extend the memory of the processor is by using a Mega. RuggedCircuits has a shield to do this but it is not as big as 1M because of the restrictions on the memory map address space. It is only 512K. http://www.rugged-circuits.com/new-products/quadram

rati: hi,I'm looking for additional memory ebaut 1mb minimum Can you help me

Are you after additional program (flash) memory, or data (RAM) memory?

rati: hi,I'm looking for additional memory ebaut 1mb minimum Can you help me

What is it you keep forgetting? :roll_eyes:

Paul__B: What is it you keep forgetting? :roll_eyes:

Ha. That question could also be addressed to me, and the answer would be: "Everything". :D

quadRam, 512Kbyte

CrossRoads: quadRam, 512Kbyte http://www.rugged-circuits.com/new-products/quadram

I was thinking Microchip 23LC1024 1Mb (128Kx8-bit) chip, but the QuadRAM shield looks much bigger and better at 512 kilobytes.

OldSteve: I was thinking Microchip 23LC1024 1Mb (128Kx8-bit) chip, but the QuadRAM shield looks much bigger and better at 512 kilobytes.

This shield is only for the Mega. Is rati going to use a Mega? The ATMega2560 and some other Atmel uCs have a specialized interface called EMI (External Memory Interface) that allow for this. Using EMI , the microcontroller can map the external memory directly (more or less) into the address space so no mucking about with SPI or I2C transactions and it's very fast. It's explained in chapter 9 of the datasheet (also here: http://andybrown.me.uk/2011/08/28/512kb-sram-expansion-for-the-arduino-mega-design/). This feature is not on the ATMega128P. It requires 24 pins near as I can tell and that would take every single non-power pin on the ATMega128P, at least the DIP version, so it is no surprise Atmel didn't include it.

Build from the link above. This guy did it all himself and it doesn't look too hard at all.

http://andybrown.me.uk/2011/08/28/512kb-sram-expansion-for-the-arduino-mega-build/

JoeN: This shield is only for the Mega. Is rati going to use a Mega? The ATMega2560 and some other Atmel uCs have a specialized interface called EMI (External Memory Interface) that allow for this. Using EMI , the microcontroller can map the external memory directly (more or less) into the address space so no mucking about with SPI or I2C transactions and it's very fast. It's explained in chapter 9 of the datasheet (also here: http://andybrown.me.uk/2011/08/28/512kb-sram-expansion-for-the-arduino-mega-design/). This feature is not on the ATMega128P. It requires 24 pins near as I can tell and that would take every single non-power pin on the ATMega128P, at least the DIP version, so it is no surprise Atmel didn't include it.

Build from the link above. This guy did it all himself and it doesn't look too hard at all.

http://andybrown.me.uk/2011/08/28/512kb-sram-expansion-for-the-arduino-mega-build/

JoeN: This shield is only for the Mega. Is rati going to use a Mega? The ATMega2560 and some other Atmel uCs have a specialized interface called EMI (External Memory Interface) that allow for this. Using EMI , the microcontroller can map the external memory directly (more or less) into the address space so no mucking about with SPI or I2C transactions and it's very fast. It's explained in chapter 9 of the datasheet (also here: http://andybrown.me.uk/2011/08/28/512kb-sram-expansion-for-the-arduino-mega-design/). This feature is not on the ATMega128P. It requires 24 pins near as I can tell and that would take every single non-power pin on the ATMega128P, at least the DIP version, so it is no surprise Atmel didn't include it.

Build from the link above. This guy did it all himself and it doesn't look too hard at all.

http://andybrown.me.uk/2011/08/28/512kb-sram-expansion-for-the-arduino-mega-build/

Thanks for the extra info, Joe. Most interesting. Somehow I missed Grumpy Mike's original reference to the QuadRam, too. I just spotted it. He might have added that bit after my first reply.

So far I've only used the ATMega328P and ATtiny85, and haven't even read their datasheets cover-to-cover yet, but I'll be getting some ATMega2560s pretty soon. I've mostly used PIC chips in the past, only recently moving to Atmel, so immediately thought Microchip and serial SRAM when I saw this thread about memory expansion. I had no idea about the EMI and the direct mapping. 24 pins is a very high cost though. :( Unless I needed the faster access, I'd probably still go with serial SPI SRAM since it's not so pin-hungry. The 23LC1024 is only an 8-pin chip, too, so has a small PCB footprint. Still, very good info, and definitely filed away for future reference. Thanks again. And rati didn't return at all after his initial post, like many others, so we don't know which Arduino he's using.

If he has an RTC, that sometimes provides a few dozen bytes right there.

Sometimes you just need just one more byte...

KeithRB: If he has an RTC, that sometimes provides a few dozen bytes right there. Sometimes you just need just one more byte...

Not quite - he said, "1mb minimum"

Which is only .001 Byte!

Sorry, couldn’t resist.

KeithRB: Which is only .001 Byte! Sorry, couldn't resist.

Fair enough. :) (I just copied and pasted from the first post, after double-checking that he did want 1mb.) But maybe he does only want an extra .001 bit. (Capital B for byte.) I couldn't resist either. :D