Noob Question

[Cotowar]

Okay, so I am planning on building a device that interacts with my computer. Its similar to a solid state drive, except its Micro SD cards in an array.

I can physically build it, no problem. I have more tools at my disposal than most people could imagine, seeing as my father works in a prototype machining shop.

I can also program quite well, and am versed in several common languages like VB, Java, C++, Ruby, and FORTRAN (don't ask about that one...lol).

My question is this though. I have been looking around on sites like Jameco and Digikey, and I have found EEPROM, and micro controllers. From what I understand, EEPROM is similar to a hard drive, in that it stores my program when the power is off. The micro controller accesses the program once the power is on, and executes the code. How does the data get from the EEPROM to the controller? That is where I seem to be having trouble. If I'm wrong about any of that, please straighten me out. Also, if the inner workings could be explained to me as to how I can manipulate the data from the EEPROM in the controller.

Oh, and I was wondering how I would take the data form the computer and distribute it to the SD cards. I know it goes in on an input line and out on an output line, but from the diagrams I've seen, the I/O is not combined together, meaning I1 can only go to O1, and so forth. Any help on this would be greatly appreciated.

 

[bacterozoid]

I think you'll find that most controllers you find are going to have some sort of program memory that you dump your code into. Whatever tool you use to program your controller should place the program here.

As far as data manipulation, they usually have a RAM section too where you can keep any data while powered on. A lot of controllers have options for extended memory if you need it, but I don't know that much about it.

In fact, I feel like I'm shooting in the dark here since I'm fairly new to controllers myself. I hope someone can confirm what I've said and help you with your other questions. Good luck!

 

[Cotowar]

That makes my life easier. My first project is an invention that does not yet exist. I'm planning on building a solid state drive from Micro SD cards in RAID 0, and running the ext3 filesystem on them so I can install Linux and have a W00t awesome computer. I think I can interface it with a SATA II connection, but I have no idea how to go about taking the data from the cable and transferring it to the SD cards. Also, I have no idea how to retrieve my data from the SD cards and sending it to the cable.

 

[Torben]

That makes my life easier. My first project is an invention that does not yet exist. I'm planning on building a solid state drive from Micro SD cards in RAID 0, and running the ext3 filesystem on them so I can install Linux and have a W00t awesome computer. I think I can interface it with a SATA II connection, but I have no idea how to go about taking the data from the cable and transferring it to the SD cards. Also, I have no idea how to retrieve my data from the SD cards and sending it to the cable.

That would be a really neat project and I totally think you should build it, but if by w00t you mean "fast" I think you'll be disappointed. Flash discs are getting faster all the time but for the price you can get a pretty sweet SATA or even SCSI (if that floats your boat ) drive which will probably beat the flash array in speed (except maybe read latency). And ext3 is for journalling and can do the job but won't get you any better speed than ext2 (if speed is what you're after, that is)--except you won't have to wait through as many fscks after power outages.

Make sure you use fairly recent flash drives with large sizes (+1GB). . .they should prove far more reliable than older ones which didn't include wear levelling and weren't that reliable with journalling filesystems. If I understand correctly, newer cards are designed with embedded controllers to deal with the problem.


Torben