This just a note that might help someone.
While updating a project written using the old, deprecated syntax of
"prog_char" etc. I noticed a 'gotcha'.
I had a number of text strings:
prog_char txt1[] = "Some txt";
prog_char txt2[] = "Some more txt";
... etc
and an array of pointers to them:
prog_char* ptrs_to_text[] = {txt1, txt2 ...}; // Case 1
The new version is:
char txt1[] PROGMEM = "Some txt";
char txt2[] PROGMEM = "Some more txt";
... etc
and an array of pointers to them:
char* ptrs_to_text[] PROGMEM = {txt1, txt2 ...}; // Case 2
Seeing that nothing worked any more, I investigated.
In case 1, the strings are in flash, but the array is in ram.
Case 2 has both the strings and the array in flash, as needs a
pgm_read_word to access each pointer.
It's sort of obvious after the event but I though I'd point it out.
Perhaps a small mention on the website where the "prog_char" stuff is
mentioned as deprecated?
Regards,
Bob
--
The Sun is out, the sky is blue, it's time to drive the MR2.
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