EEPROM Upgrade OK?
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EEPROM Upgrade OK?

by wifigod on Thu Jan 26, 2012 6:22 pm

Hey Guys,

I read around the forums and the build instructions and it would seem like this chip will work just fine, but I wanted to make sure as previous posts were using 16K or 512K (not working) chips. I plan on using a 24LC256, specifically the one found on this page: http://www.sparkfun.com/products/525 Any issues I should expect? I believe it's the maximum that the SpokePOV kit will support without further modification of hardware/code.

Thanks!
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Re: EEPROM Upgrade OK?

by adafruit on Fri Jan 27, 2012 12:28 pm

24LC EEPROMs are NOT compatible at all
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Re: EEPROM Upgrade OK?

by wifigod on Fri Jan 27, 2012 3:04 pm

Awww, Sad Panda. :cry:

Would the AT25256B work? Essentially, what is the largest EEPROM I can throw into the board and still have it load images? :mrgreen:
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Re: EEPROM Upgrade OK?

by adafruit on Fri Jan 27, 2012 6:46 pm

we havent tested the extra large eeproms lately but at one point we did have 25 x 256 working - its kind of an extra thing and not guaranteed to work. the 4 image EEPROMs are guaranteed to work as they come with the kit
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Re: EEPROM Upgrade OK?

by wifigod on Fri Feb 03, 2012 8:31 pm

25 x 256 is worthless to me without any context. I don't know what that means. 25 images with 256 bits used for addressing? I'm really trying my best at solving this myself, but the descriptions on all the EEPROM datasheets are beyond confusing. So far, I've wasted over $40 on incompatible chips and would just like some sort of push in the direction I need.

I understand that I need an SPI EEPROM, supposedly from the 24LC* family of EEPROMs from Microchip. What I don't understand is "8K" "16K", etc. K-what? Bits? Bytes? I'm guessing bits, but have no idea. Does organization matter, aka the Page sizing? Each set of chips has about 5 sets of numbers than are all different across the board and I can't quite understand how one is supposed to figure it out on their own.

My apologies for the lack of experience in this field, but I do feel I'm an ok problem solver in general, but I'm coming to my final thread.

Does 25 x 256 mean 25LC256?? Looking at the datasheet, it would seem that the 256 refers to Kbit, which means this would be a 32KB chip? That would give 32 images, right? From what I read in other posts (it's hard to follow, because you post incorrect information and when somebody points it out you just erase that info with no further explanation as to what it should have said in the first place) there is a limit of 16 images in the software/hardware, is this correct? How would 16 images fit on 32KB of data if each image takes 1KB of data? I hope you can empathize with my situation, as I'm not trying to complain and am very happy with my $300 purchase from you. It's just really discouraging to waste all this money on guessing for chips, and is really making me second guess my follow-up order I wanted to place next week ($200+ worth of items). Again, your quick replies and friendly service is most definitely appreciated, but your replies are still getting me nowhere.

Thanks,

-Ian-
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Re: EEPROM Upgrade OK?

by adafruit on Mon Feb 06, 2012 1:29 pm

I understand that I need an SPI EEPROM, supposedly from the 24LC* family of EEPROMs from Microchip. What I don't understand is "8K" "16K", etc. K-what? Bits? Bytes? I'm guessing bits, but have no idea. Does organization matter, aka the Page sizing? Each set of chips has about 5 sets of numbers than are all different across the board and I can't quite understand how one is supposed to figure it out on their own.


no, as we made clear earlier, the 24LC series will NOT work.

My apologies for the lack of experience in this field, but I do feel I'm an ok problem solver in general, but I'm coming to my final thread.

Does 25 x 256 mean 25LC256?? Looking at the datasheet, it would seem that the 256 refers to Kbit, which means this would be a 32KB chip? That would give 32 images, right? From what I read in other posts (it's hard to follow, because you post incorrect information and when somebody points it out you just erase that info with no further explanation as to what it should have said in the first place) there is a limit of 16 images in the software/hardware, is this correct? How would 16 images fit on 32KB of data if each image takes 1KB of data? I hope you can empathize with my situation, as I'm not trying to complain and am very happy with my $300 purchase from you. It's just really discouraging to waste all this money on guessing for chips, and is really making me second guess my follow-up order I wanted to place next week ($200+ worth of items). Again, your quick replies and friendly service is most definitely appreciated, but your replies are still getting me nowhere.

Thanks,

-Ian-


the 25LC256 at one point did work and could store 32 images. HOWEVER it is a hacky EXTRA and not guaranteed whatsoever to function - its been many years since we last tried it. we suggest buying 1 25LC256 DIP chip and trying it out. the only thing we can guarantee is that the original kit that we sell with 4 banks works.
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