Microcontroller Storage - HELP !

[jeyes56]

Hi,
i would like to know if it is possible for a micro-controller to save additional data without reprogramming it.

for example, i have an RF Reader, and if i press a button on a micro-controller, the ID of a RF Tag will store on the micro-controller.

//Register your RFID tags here
char tag1[13] = "1E009A4067A3";
char tag2[13] = "010230F28243";
char tag3[13] = "01023C013A04";
char tag4[13] = "01023101093A";
char tag5[13] = "01023C0A4376";
int maxtag=5;

another example is, if i would like to alter the predefined data on the code without reprogramming/rebuilding it so that i can have additional tag6[13] and the maxtag will become 6 and this data's will remain even if the micro-controller is powered off and switched on again.

I am asking if it would be possible.

thank you for any response.

 

[Nigel Goodwin]

Yes, many (if not most) microcontrollers have an area of data EEPROM specifically for such a purpose, and many modern ones allow you to write directly to program memory to store data as well.

 

[jeyes56]

can you tell one of this micro-controllers? does arduino and zilog are one of them?

also, what does this process called?

 

[Nigel Goodwin]

can you tell one of this micro-controllers? does arduino and zilog are one of them?

also, what does this process called?

I can't help you on those, but on a PIC it's called data EEPROM, and is at a high memory address, and accessed in a specific special way explained in the datasheets.

I would suggest you download the datasheet for the processor you're thinking of using (an Arduino isn't a processor, it's a development system based on an AVR).

 

[AtomSoft]

Wow for someone doing RFID stuff you seemed to skip a ton of the basics. I never use eeprom but know about it. What MCU are you using for this project? Did you even read the datasheet to see if it has eeprom? If not you can still use external eeprom. Which come in various sizes.

 

[jeyes56]

im planning to use a ZILOG or a PIC MCU,

my first plan is just to get the data from RDIF to microcontroller, and compare the data (RFID tag #) from the predefined list of allowed RFID tag #'s,

and i think of adding a master RFID Tag so that i can add additional list of allowed tag # that's why im asking about an eeprom. i think its the solution. but im getting problem how to code it..

 

[ghostman11]

how about using a sd card? or something along those lines

 

[Diver300]

how about using a sd card? or something along those lines

I think that an SD card is overkill, and there are much simpler solutions.

I would suggest, easiest first:-
1) Use a microcontroller with internal EEPROM
2) Use a microcontroller that can modify its own program memory and use an area of that.
3) Use an external EEPROM, such as a 24LC01

There would be plenty of room in any of those for a lot of RFID tag numbers.

 

[Nigel Goodwin]

im planning to use a ZILOG or a PIC MCU,

my first plan is just to get the data from RDIF to microcontroller, and compare the data (RFID tag #) from the predefined list of allowed RFID tag #'s,

and i think of adding a master RFID Tag so that i can add additional list of allowed tag # that's why im asking about an eeprom. i think its the solution. but im getting problem how to code it..

For a start you need to consider how much data space you actually need - do you know?.