This Arduino library simplifies the definition and use of Arduino flash-based
(PROGMEM) global string constants. It supports both C and C++ style coding.
API docs are in FlashStringTable.h.
Via PlatformIO see: https://platformio.org/lib/show/12513/FlashStringTable/installation
Via Arduino IDE use the Library Manager:
#include <Arduino.h>
#include <FlashStringTable.h>
BEGIN_FLASH_STRING_TABLE(myFlashStringTable)
ADD_FLASH_STRING("1")
ADD_FLASH_STRING("second")
ADD_FLASH_STRING("third")
END_FLASH_STRING_TABLE()
void setup() {
// NOTE: Call this only once. It scans the string table in flash and
// assigns pointers to myFlashStringTable's elements. It uses malloc()
// to allocated myFlashStringTable[].
INIT_FLASH_STRING_TABLE(myFlashStringTable);
// prints 3
Serial.print(myFlashStringTable_size, DEC);
// prints "second"
Serial.println(myFlashStringTable[1]);
}
void loop() {
}#include <Arduino.h>
#include <FlashStringTable.h>
BEGIN_FLASH_STRING_TABLE_CLASS(Piggy)
ADD_FLASH_STRING("Mrs")
ADD_FLASH_STRING("Piggy")
ADD_FLASH_STRING("Loves")
ADD_FLASH_STRING("Kermit")
ADD_FLASH_STRING("The")
ADD_FLASH_STRING("Frog")
ADD_FLASH_STRING("!")
END_FLASH_STRING_TABLE()
class Piggy : public Printable {
public:
Piggy() : strings(_progmem_Piggy) {} ;
size_t printTo(Print& p) const { return p.print(strings); };;
StringTable strings;
};
void setup() {
while (!Serial && !Serial.available()) {}
Piggy piggy;
char sz[256];
sprintf_P(sz, PSTR("Piggy has %d strings"), piggy.strings.getNumStrings());
Serial.println(sz);
Serial.print(PSTR("Piggy's printTo() says: "));
Serial.println(piggy);
Serial.print(PSTR("Piggy's strings: "));
for (uint16_t i = 0; i < piggy.strings.getNumStrings(); i ++){
sprintf_P(sz, PSTR("%d = %s, "), i, piggy.strings.getString(i));
Serial.print(sz);
}
Serial.println(PSTR("Done!"));
}
void loop() {
}There is a small startup cost to using this library as each table of strings is parsed by the INIT_FLASH_STRING_TABLE
macro to fill in the table of __FlashStringHelper* pointers. However,