Save strings in EEPROM

Forum 2005-2010 (read only) Software Troubleshooting
1

Hi,
I want to save some strings in EEPROM, which have an uncertain length and am not sure how to do this. Does anyone know a way of doing this?

Thankyou in advance...
Conor :slight_smile:

2

Decide how many strings you think you want to save, and store a simple index array at the start of EEPROM to point to the strings.

3

Strings are terminated with 0. You can have the strings one after the other, no matter their length.

4

You can have the strings one after the other, no matter their length

But you still need to know where they start..

5

if I try to save strings in EEPROM I get an error message... :frowning:
How would I go about saving them as an array?

:slight_smile:

6

What is the C code you use to try to save the strings?

What is the error message?

7

You need a function like this, whereby:-

newWriteLocation is the start position in eeprom
byteCount is the length of yourString

EEPROM.write(newWriteLocation+byteCount, int(yourString[byteCount]));

Once you start storing data in eeprom, you might need additional routines to:-

search records
delete records
add new records
determine number of free blocks available

And each of those routines need supporting routines, like you might want to use 2 large arrays, both the same size as eeprom, that you manipulate before writing the entire array back to eeprom, especially if your trying to delete a string and reorder the eeprom to make more efficient use of the available space after the strings been deleted.

It's a real can of worms unless you can find code in the playground that already does what your wanting.

8

conanim, you may want to take a look at my recent post here:

A bit of explanation, a bit of code...