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Eeprom memory


#1

Hi, How can i Store a Variable for my proyect and keep the value even after disconected?

Do i need an eeprom?

24LC256, will be good?

how do i wire it to my panda?


#2

You can use ExtendedWeakReferences on boards that support it - FEZ Spider and FEZ Cobra. For other boards, use InternalFlashStorage. Google should have info for both APIs.

I think these can only be written some number of times before they stop working. Not sure what the limit is but suspect it’s around 10k. Might be 1k or 100k but I’d be surprised if it was under 1k.

edit: http://www.sparkfun.com/products/525 is a 24LC256 and you talk to it through I2C. Never played with that stuff myself but it should work - should be able to find some FEZ I2C examples with just a little searching.


#3

Ok…

when you mean that it can only be written some number of times before they stop working, do you mean the InternalFlashStorage?

If so i will go for the I2C eeprom chip option, yes there are even drivers on the code page, i just wanted to know how to wire it to the panda…


#4

Check out the InternalFlashStorage Class in the GHIElectronics.NETMF.Hardware namespace.


#5

InternalFlashStorage does have a limit of writes?


#6

I think all these sorts of devices will have a limit - the spec for the 24LC256 says it’s a million read/write cycles.

The ones built into the FEZ boads may also have a similar high limit - I truely have no idea what the number is.


#7

@ Omartinez, you wire the 24LC256 up by connecting it to the I2C pins - of which there are only two. Simplistically it takes a power source, GND and the two I2C pins Di2/Di3. if you’re using a “raw” chip you also need to set the address bits by tying the address pins to GND or VCC.


#8

From the documentation for the InternalFlashStorage class.