Hi, I have the following struct:
struct ScaleStruct
{
String Name;
uint8_t size;
uint8_t width1; //Without Fitting the scale
uint8_t width2; //fitting the scale
uint16_t ScaleMapping;
};
I have 12 instances of this struct declared on my sketch:
ScaleStruct Scale[12];
The thing is that all the data stored inside the structs are Constants, and I want to know if it it posible to move them to the Program Memory, and if so, how do I do it??
This is an example of how I fill the data of the structs:
uint8_t KeyCount = 55; // BUTTONS - 1
Scale[0].Name = F("Chromatic");
Scale[0].size = 12;
Scale[0].width1 = KeyCount;
Scale[0].width2 = KeyCount;
Scale[0].ScaleMapping = 0b0000111111111111;
Scale[1].Name = F("Major");
Scale[1].size = 7;
Scale[1].width1 = KeyCount + 40;
Scale[1].width2 = KeyCount + 29;
Scale[1].ScaleMapping = 0b1000010110101011;
Scale[2].Name = F("Natural Minor");
Scale[2].size = 7;
Scale[2].width1 = KeyCount + 40;
Scale[2].width2 = KeyCount + 29;
Scale[2].ScaleMapping = 0b1000011010110101;
The data never changes in the code
Thanks!
I solved it.
For anyone wanting to know, this is what I did.
I changed:
ScaleStruct Scale[12];
to :
const ScaleStruct Scale[12] PROGMEM =
{
{"Chromatic", 12, 55, 55, 0b0000111111111111},
{},
{},
{},
{},
{},
{},
{},
{},
{},
{},
{},
};
All the data is loaded when declared, and for Example, I can just call Scale[ x ].Name, right?
I'm a bit confused.
J-M-L
September 10, 2017, 3:27pm
#3
it’s a bit convoluted and you need to know what is the format of the data stored
here is an example
#include <avr/pgmspace.h>
enum situation_t : uint8_t {single, couple, RIP};
// this is the standard approach for Arrays of strings as documented in https://www.arduino.cc/en/Reference/PROGMEM
const char s0[] PROGMEM = "single";
const char s1[] PROGMEM = "couple";
const char s2[] PROGMEM = "rest in peace";
const char* const descriptionSituation[] PROGMEM = {s0, s1, s2};
// Now if you want your own structure and have some strings as well in the structure
struct myStructure {
const char * firstName;
const uint8_t d;
const uint8_t m;
const uint16_t y;
situation_t situation;
};
//the strings are char array, you define them first somewhere in flash memory
const char auguste[] PROGMEM = "Auguste";
const char camille[] PROGMEM = "Camille";
const char victor[] PROGMEM = "Victor";
const char juliette[] PROGMEM = "Juliette";
const char cheche_romo[] PROGMEM = "Cheche Romo";
// and then use the reference for your table definition
const myStructure population[] PROGMEM =
{
{auguste, 12, 11, 1840, RIP}, // the structure holds a pointer in memory for the first name
{camille, 8, 12, 1864, RIP},
{victor, 26, 2, 1802, RIP},
{juliette, 10, 4, 1806, RIP},
{cheche_romo, 1, 1, 2000, single}
};
const uint16_t nbElements = sizeof(population) / sizeof(population[0]);
void setup() {
char buffer[30]; // needs to be large enough
Serial.begin(115200);
for (int i = 0; i < nbElements; i++)
{
Serial.print(F("------------ ")); Serial.print(i); Serial.println(F(" ------------"));
strcpy_P(buffer, (char*)pgm_read_word(&(population[i].firstName)));
Serial.println( buffer );
Serial.print( (uint8_t) pgm_read_byte_near(&(population[i].d)) ); Serial.print("/");
Serial.print( (uint8_t) pgm_read_byte_near(&(population[i].m)) ); Serial.print("/");
Serial.println( (uint16_t) pgm_read_word_near(&(population[i].y)) );
strcpy_P(buffer, (char*)pgm_read_word(&(descriptionSituation[(uint8_t) pgm_read_byte_near(&(population[i].situation))])));
Serial.println( buffer );
}
Serial.println(F("------------------------------"));
}
void loop() {}
Great!, got it working now, thanks! =)
J-M-L
September 10, 2017, 5:47pm
#6
have a look at my example in #2
