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Electronics => Electronics => Topic started by: MarkBrown on August 17, 2008, 07:28:36 PM

Title: Extending the memory of a chip
Post by: MarkBrown on August 17, 2008, 07:28:36 PM

Does anyone know if it is possible to extend the amount of memory on a chip like the ATMega8 by using a thumb drive or some other means?

Mark

Title: Re: Extending the memory of a chip
Post by: Ro-Bot-X on August 17, 2008, 08:14:08 PM

I know it is possible with a I2C or SPI interface EEPROM. You can use that memory for map storage, datalog, something like that.

I also know that the OOPIC controller has an interpreter onboard the PIC and when you download your program, it stores it in an external EEPROM and at running it reads the code line by line and executes the instructions. Unfortunately, this method adds a lot of overhead to the execution of all instructions, so this is why some things that require a very short amount of time can't be used with OOPIC (for example, the Ping))) sensor requires a trigger signal of 5 microseconds, impossible to generate with the OOPIC).

I think I have seen something on the Arduino website about interfacing with a SD memory card or Compact flash card...

Title: Re: Extending the memory of a chip
Post by: MarkBrown on August 17, 2008, 08:38:44 PM

Thanks.  I hadn't thought of trying to use an SD card.  I will do some more research.

Title: Re: Extending the memory of a chip
Post by: TrickyNekro on August 18, 2008, 09:33:10 AM

I don't think there is any mean in doing this...

If you want extra memory move up to the other ATmegas...
For example ATmega128 has 128kB of memory...

Endless... You would never ever need so much memory unless you try building a gaming machine...

Title: Re: Extending the memory of a chip
Post by: MarkBrown on August 18, 2008, 09:57:35 AM

There are two purposes behind this. 

One, I wanted to know if there was a way of extending a chips existing memory using outside chips or flash drive or other means 
Two, I would rather not get an upgrade until I am ready for it.  I am still learning how to use the ATmega8 to its full potential.

Mark

Title: Re: Extending the memory of a chip
Post by: pomprocker on August 18, 2008, 10:57:36 AM

I tried doing that too, but an atmega8 barely has enough room to put functions in to control 3 or 4 sensors, plus a few servos, uart, etc...i ran out of room on it right when i added my sonar code....so luckily I had ordered my ATmega168 before I needed it, so the two are pretty much interchangeable

Title: Re: Extending the memory of a chip
Post by: MarkBrown on August 18, 2008, 01:46:22 PM

It is good to hear that I am not the only one with that mentality.   :)   If the 168 and the 8 are fairly interchangeable then I will look into this one.

Title: Re: Extending the memory of a chip
Post by: pomprocker on August 18, 2008, 03:11:33 PM

they have the same pins and the same size, the mega8 as 8k, the mega168 has 16k for a couple more bucks

ATMEL actually puts their  chips into "Families" where they have the same pinout, then just have more and more features.

Like atmega8, 48, 88, 168..etc

http://www.atmel.com/dyn/products/devices.asp?family_id=607#760