Expanding memory for sx-28

Jim Barnes

Hi gang,

I want to temporarily store 256 values gathered during a sampling algorithm and then post process them to find the best fit for my task, then get rid of all but the chosen value.· I think that the SX-28 is limited to 19 variables or an array of 16 elements.· Is that correct?· Any way around this?· Can I use...choke.... an external memory chip?

Thanks a lot,

Jim

Bean

Jim,
SX/B 2.0 does allow large arrays on the SX28, but there is still nowhere near 256 bytes available.
An external memory chip would be the best way. There are serial SRAM chips that would work with a minimum of pins required.
Sorry I cannot remember what they are at the moment.

Bean.

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There is a fine line between arrogance and confidence. Make sure you don't cross it...

·

Jim Barnes

Thanks Bean,

How 'bout using the SX-48?· Does that give me enough variable room?

Thanks again

John Couture

Another solution might be to use a memory chip and talk to it via I2C. (ground, SDA, SCL).

The only part number I have is 24C164 which is 16K bit (2048 x 8) but I'm sure there are newer parts available. My notes say I got these for about $0.25 a couple of years ago.

Another thought is the use of an SD card. This is a pricy option but virtually unlimited storage (and slower). For example, and SD card reader is about $50 and you can plug in megabytes of storage. More than likely the battery on your MCU will give out before you run out of storage!

Finally, remember that your PROGRAM has to fit on the SX chip, but DATA can be on an external device and you can have an unlimited amount of data (subject to limitations of whatever external device you use).

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John J. Couture

San Diego Miramar College