Reduction of memory usage? about arduinomenu HOT 14 CLOSED

Each time I had used F() macro on String I never noticed big savings on memory usage.
Maybe it worth it on large menu, otherwise I'm not really sure.
You (I mean not you directly, but much more people) can also think to save memory by using the smallest data type capable of holding the information. i.e. uint8_t instead of int (1 byte saved each time), etc.

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Just sent update with text strings and menu data stored in PROGMEM
next i might target preferences...

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probably yes #6

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yeah I have read that and I have read a couple tutorials to use PROGMEN but I am not able to get this infos into my sketch. Could you give an example?

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not yet, it was just an idea

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I've send updates for some navigation bugs, support for looping menus, and U8glib support, guess i will read something about progmem

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I guess a good start would be to use the F ( ) Macro like in lcd.print(F("Hallo")); or here https://www.arduino.cc/en/Reference/PROGMEM :) just as an idea.

I am pretty much a hobby programmer so I am dependent on your grace ^^

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ok I guess it will be nessasary to work with string as all the other Menu's out the, as I startet my project I had no idea why they using them, but now it's clear, it saves memory. Insteard of putting the "Text" in a Field there should be a

const char mainMenuSTRING_ID_0 [] PROGMEM = "Aquarium"
const char mainMenuSTRING_ID_4[] PROGMEM = "Exit Menu"

MENU(mainMenu, mainMenuSTRING_ID_0,
SUBMENU(subMenuTemperature),
SUBMENU(subMenuTimer),
SUBMENU(subDateTime),
OP(mainMenuSTRING_ID_4, pauseMenu)
);

And then the libary need the read the PROGMEN with pgm_read_word_near(mainMenuSTRING_ID_0);

And there my knowlege stop's, cause I don't fully understand the MACROS of the lib...

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I pointed out this example and discussion on Arduino forum, http://forum.arduino.cc/index.php?topic=110307.0, maybe this can help you to implement PROGMEM text var.
I tried on my side but I'm stuck and got a lot of errors, mostly in the MACRO part definition, because I do not understand all the syntax you are using to generate the menu.

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I've done some checkings, by moving strings and menus data (list of options) to PROGMEM and it is not a big saving.. still checking

pratical compile measures ---------------------------
nomenu 622
normal menu 1119 - 497
progmem menu 1067 - 445 (text and data lists to progmem)
saved 52

structures sizeof ----------------------------------
promptAction: 2
prompt: 7
menu: 22
menuValue: 9
menuField: 33
menuSelect: 24
menuChoice: 24
menuToggle: 24

rough estimates =====================================

menu struct:
lists 4
prompts 2+2+7+6+4=21

strings ------------------------------------------
texts: 2+2+7+3+4=18
chars: 10+9+24+24=67
total chars: 67+18=85 (zero terminated)

test menu struct size ----------------------------
values: 9x9=81
ops: 4x7=28
fields: 1x33
menu: 4x22=88
total: 81+28+33+88=230

even moving text and data to flash, the remainder of menu structure is bigger than the moved part
as we normally use short texts due to small screen usage, I think we can save only less than 20% of menu ram space.. not very good

to make bigger savings all menu structure would have to be revised by separating things that can be constant and status variables, in some cases with worst results. A simple prompt can be all in progmem except for the enabled status var, spliting the class between memory types will result in more memory usage.
some status variables can be moved out of the structure by making a navigation stack...

things for version 3 i guess

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I my project I have a lot blank space character to format the print. I guess other users do that too, so I thought, and I am actullay not sure if blank space character getting saved in strings, it could be good to implement a Format class so that just the nessasary characters will be saved.
Meanwhile I orderd a Mega ;)

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yes, datatypes are important and in some cases we can exchange data by code...
example, the prompt class can be all const (progmem) except for the "enabled" bool...
I can sacrifice an extra byte on flash mem (progmem) and use a pointer to a function that returns the enabled state. that way the function pointer is const (can go to flash mem) , we loose a bit of performance because we have to execute the code for every check, but all the prompt data will exist as one object in flash.
have to check other classes about separation between const (compile time->progmem) and dynamic data. And avoid splitting the object as much as possible.

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and yes, blank space is stored, you can use tabs, but your driver must understand tabs
and all strings terminate with a zero byte (c convention).
but string are probably less than 30% of the data

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here's a small code that uses no macros if you want to play with PROGMEM

bool ledOn() {return false;}//returning true here makes the menu exit after
bool ledOff() {return false;}

prompt sub1("LED ON",ledOn);
prompt sub2("LED OFF",ledOff);
prompt* const subMenuData[]={&sub1,&sub2};
menu subMenu("Sub-menu",2,subMenuData);

prompt empty("Empty");

prompt* mainMenuData[]={&subMenu,&empty};
menu mainMenu("Main menu",2,mainMenuData);

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