character string array in AVR Studio (AVR GCC)

[ark5230]

I am new to C and C++ but trying to use with AVR.
I am trying to use character string array like
a[1]="Name - 1"
a[2]="Name - 2"
a[3]="Name - 3"
a[4]="Name - 4"

Any resource or suggestion to declare and use such subscripted character string variable.
Storing in program memory or RAM will do.
If all goes will I wish to use it with EEPROM, I checked and test use of EEPROM with simple data.

 

[alexan_e]

To declare an array of null terminated strings in C you can use

char my_ram_array_of_strings[][9] = { 	"Name - 1",
					"Name - 2",
					"Name - 3",
					"Name - 4"};

The characters can then be acceded using my_ram_array_of_strings[y][x] where y is the vertical position (starting from 0 which is the top string) and x which is the horizontal position (starting from 0 which is the leftmost character)



Check
https://pages.cpsc.ucalgary.ca/~jacob/Courses/Fall00/CPSC231/Slides/10-ArraysAndStrings.pdf

 

[ark5230]

Thanks a lot for complete and useful answer, It solved my current problem.
As mentioned in first mail, if I go for EEPROM with little larger number of elements, is it possible to define number of element in declaration and that too without initialising. I will carefully go through the PDF, this may also give some hint of direction.
It compiles however it seems it is accessing the character at [y] [x] and not the array at a time.

 

[alexan_e]

The xy coordinated access one char at a time, there is no string type in C.
There is a string manipulation library in libc that may come handy https://www.nongnu.org/avr-libc/user-manual/group__avr__string.html

The eeprom access is done using https://www.nongnu.org/avr-libc/user-manual/group__avr__eeprom.html
You can read this tutorial

Also for variables stored in flash https://www.nongnu.org/avr-libc/user-manual/group__avr__pgmspace.html
And this is a tutorial

 

[ark5230]

Thanks a lot, this is great stuff, I will print and study. This will help resolve many future issues. However if I dont understand a specific issue, I will post the same. I will try to avoid use of string type and try to modify code to implement the desired functionality using character arrays.

 

[alexan_e]

I think Atmel studio 6 supports C++ which will give you additional features but I have no knowledge of C++ so I can't help you and usually it is not a good idea to use it for small microcontrollers because of the limited resources

 

[ark5230]

I am using Atmega32.

Atmel studio 6

This refers to AVR Studio 6 or it is different, I am using AVR Studio 4, it supports C++ and is freely available, but dont know if AVR Studio 6 is freely available, will find out from Atmel Site.

I have no knowledge of C++ so I can't help you

You have already helped me out (also earlier in different areas on this forum)
Thanks again

 

[alexan_e]

avr studio 4 is the older version, actually the one that I still use with winavr.
The latest version of the suite is version 6 and its also free, it also includes the Atmel framework which is Atmels version of winavr so there is no need to install winavr.
There is also version 5 but avoid it.

For older devices like the one you use both version 4 or 6 will work fine, for some new devices you will have to use v6.