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What's everyone's go to 64k eeprom ? — Parallax Forums

What's everyone's go to 64k eeprom ?

Don MDon M Posts: 1,647
in Propeller 1
Which manufacturer and specs do you look for? Part numbers? Thanks.

Comments

  • Peter JakackiPeter Jakacki Posts: 10,193
    Depends upon package, availability, pricing, speed etc. I'm using an ST part at present that supports 1MHz I2C, 128 byte pages and is available in TSSOP, oh, and cheap.

    Have to get back when I find the part number.
  • Tracy AllenTracy Allen Posts: 6,656
    Atmel AT24C512C-XHM in tssop8/msop8.


  • Bill HenningBill Henning Posts: 6,445
    I use Microchip's 24LC512's
  • Peter JakackiPeter Jakacki Posts: 10,193
    Found the part number M24512-RDW6TP which is half of the price of the equivalent Microchip part, only about 60 cents in 500s
  • ErNaErNa Posts: 1,742
    I'm using on my boards STM M24M01-RDW6TP 1 MBit eeproms, as I expect to have never enough of memory.
  • Dave HeinDave Hein Posts: 6,347
    Parallax sells the M24512-RDW6TP. However, the price is substantially higher than the one Peter posted.
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2016-05-07 12:58
    @ErNa Although it is easy enough to have more EEPROM there is a limit that is practical, usually based upon the application. For under $2 you can have a super fast 8MB SPI flash instead, or for a few dollars more a 8GB microSD, depends upon the application.

    @Dave Hein - yeah, a bit more but you hand over your money and you get an "education" :) I see they sell a single (1 off) 2-pin jumper for 99 cents!!!!! What's the idea there, that's plain crazy, at least sell them as a pack of 10 or even 5 for that price. But then again the Propeller chip is a real steal even at $8 for this type of chip produced in such small quantities, it has proven itself both as a very versatile and reliable chip, as well as dependable supply unlike many big semis who chop and change and eol.

    So comparing what you can get from Parallax for $8, you can get an MCU with eight 32-bit cores or you can get 8 jumpers instead, go figure..
  • Tracy AllenTracy Allen Posts: 6,656
    @Peter, What jumper is that? All I see is a 10-pack for $1.99. Not unreasonable!?
    I'm not sure how many here are doing OEM builds of 500, but it does pay to shop around. At present Arrow/Verical excess inventory AT24C512C-XHM for US$0.3832 @ qty200, shipping from Netherlands.

    @Erna, I've used the AT24CM01-XHM (128kx8) for a data logger that needed minimum chip count. The big challenge with that one was that the data had to be stored in a compressed format and then read out very quickly and decompressed to send via USB. I used a modified version of Chris Gadd's pasm i2c driver. An SPI flash or SD card would have been much quicker and easier to implement.
  • PublisonPublison Posts: 12,366
    Tracy Allen wrote: »
    @Peter, What jumper is that? All I see is a 10-pack for $1.99. Not unreasonable!?
    I

    Peter is referring to this jumper:

    https://www.parallax.com/product/452-00009

  • Tracy AllenTracy Allen Posts: 6,656
    Oh my, that is extreme. 1876 in stock, hurry before they sell out!
  • kwinnkwinn Posts: 8,697
    Hey, at least you have a choice. One for $0.99, or 10 for $1.99.
  • Peter JakackiPeter Jakacki Posts: 10,193
    kwinn wrote: »
    Hey, at least you have a choice. One for $0.99, or 10 for $1.99.

    Or 100 pcs for $1.96 AU with free shipping from unoware. It's only a copper shunt after all.


  • Don MDon M Posts: 1,647
    So getting back to the original question--- @Peter... comparing the ST 24512 from Mouser at $0.84 / 10 to Microchip 24LC512 from Mouser @ $1.28 / 10 have you found any issues using the 24512 vs the 24LC512? I have used the 24LC512 in a few projects without issue but the 24512 from ST seems a much better value. I would hate to introduce any problems in saving $0.36. But in large quantities this is quite a savings.
  • Peter JakackiPeter Jakacki Posts: 10,193
    Don M wrote: »
    So getting back to the original question--- @Peter... comparing the ST 24512 from Mouser at $0.84 / 10 to Microchip 24LC512 from Mouser @ $1.28 / 10 have you found any issues using the 24512 vs the 24LC512? I have used the 24LC512 in a few projects without issue but the 24512 from ST seems a much better value. I would hate to introduce any problems in saving $0.36. But in large quantities this is quite a savings.

    The ST part I use in production and so it works and although I may use Microchip parts at times I am also not tied to them and a superior part at a better prices from a reputable manufacturer is always considered. So ST quote 4 million write cycles, 1.7 to 5.5V operating range at 1MHz I2C speed and a >200 year retention. That's very nice.


  • Don MDon M Posts: 1,647
    So they both operate the same without any differences?
  • Don MDon M Posts: 1,647
    In terms of spin code... the I2C object..
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2016-05-08 23:55
    Don M wrote: »
    So they both operate the same without any differences?

    I don't understand what you mean "without any differences" as they are both I2C EEPROMs with the same base address for this type of EEPROM etc, so they are all compatible as I use them without anything special being done to them.

    Using a standard 64 byte page I write 4096 bytes in 389ms
    0 $8000 $1000 LAP ESAVE LAP .LAP 389.055ms ok

    If I change the page size I get a much better 269ms - that's about 64us/byte and probably could be improved.
    0 $9000 $1000 LAP ESAVE LAP .LAP 269.332ms ok
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