B4R Question Tables in Flash program memory.

[tigrot]

Hi everybody,
I have written this module to store my table in flash and retrieve it.
Is this the correct mode to handle it without side effects?
Main code

Sub Process_Globals
    Public Serial1 As Serial
End Sub
Private Sub AppStart
    Serial1.Initialize(115200)
    Log("AppStart")
    Dim nr As UInt=3
    statica.GetString(nr)
    
    Log(statica.stringa)
End Sub

This is module(cut off for readability):

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'Public variables can be accessed from all modules.
    Public stringa() As Byte
End Sub

public Sub GetString(index As UInt) As Int 
      RunNative("getdata1", index)
      Log(stringa(1))
End Sub


#if C
#include <avr/pgmspace.h>
char strx[50];
const char string_1[] PROGMEM = "R1=SCHEDA DI TARATURA";
const char string_2[] PROGMEM = "R1A=Generata il:";
const char string_3[] PROGMEM = "R1B=Ore:";
const char string_4[] PROGMEM = "R2=Parametri generali:";
const char string_5[] PROGMEM = "R3=Prodotto in uso           :";
const char string_6[] PROGMEM = "R4=Fotocellula               :";
const char string_7[] PROGMEM = "R5=Reset manuale             :";
const char string_8[] PROGMEM = "R6=Tempo di oscuramento      :";
const char string_9[] PROGMEM = "R7=Stop su errore            :";
const char string_10[] PROGMEM = "R8=Tempo stabilizzazione     :";
const char string_11[] PROGMEM = "R9=Timeout fotocellula       :";
const char string_12[] PROGMEM = "R10=Errore mancata espulsione :";
const char string_13[] PROGMEM = "R11=Tempo sincronismo contatti:";
const char string_14[] PROGMEM = "R12=Inserita";
const char string_15[] PROGMEM = "R13=Disinserita";
const char string_16[] PROGMEM = "R14=Inserito";
const char string_17[] PROGMEM = "R15=Disinserito";
const char string_18[] PROGMEM = "PP1=Parametri prodotto : ";
const char string_19[] PROGMEM = "PP2=Nome:";
const char string_20[] PROGMEM = "PP3=Programma N.        :";
const char* const string_table[] PROGMEM  = {string_1, string_2, string_3, string_4, string_5, string_6, string_7, string_8, string_9, string_10, string_11, string_12, string_13, string_14, string_15, string_16, string_17, string_18, string_19, string_20}; 

B4R::Object* getdata1(B4R::Object* o) {
    //Serial.println(o->toLong());
    strcpy_P(strx, (char*)pgm_read_word(&(string_table[o->toLong()])));
    //Serial.println(strx);
    b4r_statica::_stringa->data = strx;
    int n=0;
    do
        n++;
    while (strx[n]!=0) ; 
    b4r_statica::_stringa->length = n;
    return 0;   
}
#end if

This code seems to work. I had to define stringa lenght to terminating null to correctly print it(like a string).
Regards
Mauro Zanin

 

[Cableguy]

Why not serialise it before saving it to memory? Strings should be avoid in b4R...

 

[tigrot]

In this case I don't directly use C++ strings. And all strings(char's) are constants stored in PROGMEM. Only read, never write.

 

[tigrot]

And the tables are much more large than this example. About 8Kb, but in MEGA we are ok.

 

[Cableguy]

So, if it works and you have no memory leaks, it's a go!

 

[tigrot]

Memory leaks. My favourite nightmare! In this case there is no runtime allocation. Hope so, at least. I'll let you know. These are strings to compile a log of activities stored on Sd.

 

[tigrot]

Tested: after start only 9 bytes of RAM memory where allocated( from 7465 to 7456 freebytes) and after 30 minutes freebytes is still 7456...
RELEASED!