Arduino Pgm_Read_Word. In order to use these functions, the target device must support either the lpm or elpm instructions. The usage of these functions will be clear in the example below.
PP_Q2.ino Wokwi Arduino and ESP32 Simulator
I have a requirement to store two dimensional arrays of numbers in progmem. Const progmem float f = 3.12; Pgm_read_word_near(address) − this function returns the value of one word (2 bytes on most microcontrollers) with location starting from address. I want to change »string_table_xx« in »pgm_read_word (string_table_xx)« dynamically. The address is in the program space. Since you know that those 16 bits are a signed integer, you should cast them to a signed integer. The compiler translates them to addresses that are actually passed to the pgm_read_word function. It says menu_str should be declared as. You couldn't meaningfully cast a 32 pointer to a 16 bit pointer, but casting to a larger size is always valid. There is no pgm_read_int_near ().
Web pointers on teensy are 32bits, so you can't cast a pgm_read_word () (which returns 16bits) to a pointer sure you can. The usage of these functions will be clear in the example below. Web detailed description #include < avr/io.h > #include < avr/pgmspace.h > the functions in this module provide interfaces for a program to access data stored in program space (flash memory) of the device. Web i am having trouble getting a correct value of double using pgm_read_dword, does anyone have any idea why this happens? The address is in the program space. However, if the format string contains %s, then the corresponding argument must be in ram, not flash memory. System january 23, 2012, 8:27pm 2. Program space utilities // const unsigned long long_table [] progmem = {1ul, 20ul, 300ul, 5000ul, 60000ul, 700000ul}; Serial.println ( (int16_t) pgm_read_word_near (&array [ i ] ), dec); Web void mainmenu() { unsigned int i = 0; There will be lots of room for the 16 bit address in the 32 bit pointer.
