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Writing to EEPROM — Parallax Forums

Writing to EEPROM

okurka11okurka11 Posts: 3
edited 2009-04-17 22:38 in Propeller 1
Hi All,
is there any code, which allows me to write data directly from Propeller to EEPROM? I need to develop some emergency procedure, which saves collected data (4kB stored in RAM) in case of power outage. This must be done very quickly and saving to external SD card is slow. I was also thinking about replacing of 24LC256 with FM24V05 (512kbits) (RAMTRON). Is it possible?

Many Thanks

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2009-04-14 14:13
    You should post messages about the Propeller in the Propeller forum rather than the Stamp forum.

    There are several objects in the Object Exchange that will do this. The simplest to use is "Basic I2C Driver".

    It will take some time to write 4kB of data. EEPROMs have "pages" where an entire page is written at one time.
    These are anywhere from 64 to 256 bytes depending on the EEPROM size and the manufacturer and writing a
    page or a single location takes about 10ms. With 128 byte pages, it would take around 300ms to write 4kB.

    RAMTRON FRAM is much faster. The FM24V05 should work.
  • okurka11okurka11 Posts: 3
    edited 2009-04-14 14:40
    Hi, thank you for your reply. I'm newbie on this forum, so I didn't noticed, that I'm on bad forum.
    So, do you think that I can replace 24LC256 with FM24V05 part for part without any changes and propeller will be able to boot from it and I will be able to use space above 32KB as fast data storage?
  • Mike GreenMike Green Posts: 23,101
    edited 2009-04-14 15:14
    I haven't tried it, but, according to the datasheet, it should work to use the FM24V05 instead of a 24LC512 (which the Protoboard uses).
  • okurka11okurka11 Posts: 3
    edited 2009-04-14 20:34
    I thought that demoboard uses 24LC256, regarding to Demo Board scheme in Propeller tool. If it uses 24LC512, there is no necessity (only because of speed) to replace it, I would have enough space for storage, because first half of EEPROM is used for program and second half is free. My demo board is more than two years old the EEPROM chip has these letters on it: 4LD I614 10F. I don't know what it means. Is it 24LC512? Am I right that 256 means 256kbits = 32kB and 512 means 512kbits = 64kB? Propellers RAM has only 32kB.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2009-04-17 21:19
    This post is being moved from the BASIC Stamp Forum to the Propeller Forum.

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    Chris Savage
    Parallax Engineering
  • Mike GreenMike Green Posts: 23,101
    edited 2009-04-17 22:38
    The Demo Board uses a 24LC256 which has 32K bytes. The Protoboard uses a 24LC512 which has 64K bytes. The Hydra uses a 24C1024 which has 128K bytes. All provide 32K for the Propeller boot process. Anything beyond 32K bytes is extra and can be accessed using any of the I2C drivers.
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