SX used as an Eeprom?

Basic Jim

Hello All,

I suspect that the answer is no but, here goes anyway. I want to store just a few variables during run time and have them come up when I turn on the circuit again. I have several spare SX28's that I don't think I will ever need because to me it is faster and cheaper to buy an SX48 proto board and put my little circuits on it rather than build and wire an SX28 circuit from scratch.

Question: Would it be at all possible to wire an SX28 so that it is always in a programming mode and use it in my circuit to store the variables that my SX48 would feed it and read from it basically using it as an EPROM?

I realize it's an off the wall idea but, why spend $10.00 plus shipping charges for a serial EPROM when a $3.85 chip could work. Too bad Parralax doesn't offer a microcontroller that would have a small amount of static memory built in. It would save a lot of time and expense.

Jim W.

Bean

Jim,
No you can't. If the turn-off time is short, you could put the SX48 into SLEEP mode. The current falls to several microAmps and all RAM is preserved.
Bean.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Cheap 4-digit LED display with driver IC·www.hc4led.com

Low power SD Data Logger www.sddatalogger.com

"I reject your reality, and substitute my own." Mythbusters
·

Basic Jim

Thanks Bean,

Maybe I can reprogram an old Bios chip from a pentium 75Mhz mother board I have in the attic from 10 years ago.

Jim

Basic Jim

How about hooking up a USB flash drive to use as external ram? Looking at the USB cable that runs from the backplane to the mother board there are only 5 wires to deal with. Seems to me that the SX should be able to do that maybe directly. Has anyone tried this? I searched the sx forums but didn't find anything.

Thanks,
Jim W.

Dave Hein

I think a USB solution would require a lot of software.· I would suggest using an external EEPROM chip.· Parallax sells the 24LC32A 4K EEPROM for $2.40.· Just go to parallax.com, click on the "accesories" link, and then click on the "integrated circuits" link.· It's the first item on the list.

Basic Jim

Thanks Dave,

I'll probably try playing with the BIOS chip which can be reprogramed. But, I will stock up on the eprom chip you sugested next time I go to the web site. Problem is, everytime I order something from Parallax I end up buying other neat gizmos and by the time I'm ready to check out I spend a couple hundred bucks. I can't help it! Right now that Professional Development board sure is tempting. I hope they go on sale.