69 lines
2.2 KiB
C
69 lines
2.2 KiB
C
/* Fourth step into using program memory */
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/* Passing data array pointers to functions */
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#include <avr/io.h>
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#include <util/delay.h>
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#include <avr/pgmspace.h>
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#include "USART.h"
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const uint16_t myData[] PROGMEM =
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{ 1111, 2222, 3333, 4444, 5555, 6666, 7777, 8888, 9999, 10000 };
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const char string1[] PROGMEM = "Hey, string one!\r\n";
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const char string2[] PROGMEM = "Oh my, string two!\r\n";
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const char *const stringIndex[] PROGMEM = { string1, string2 };
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void printData_Progmem(const uint16_t * dataPointer, uint8_t length) {
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while (length) {
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printWord((uint16_t) dataPointer); /* print out address */
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printString(": ");
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printWord(pgm_read_word(dataPointer)); /* print out data */
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printString("\r\n");
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dataPointer++; /* move to next byte */
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length--; /* one less byte to go */
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_delay_ms(100);
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}
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}
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void printString_Progmem(const char *stringP) {
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char oneLetter;
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while ((oneLetter = pgm_read_byte(stringP))) {
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transmitByte(oneLetter);
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stringP++;
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}
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}
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int main(void) {
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initUSART();
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uint8_t myArray[] = { 10, 11, 12 };
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uint8_t *p;
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uint8_t i;
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p = &myArray[0];
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for (i = 0; i < sizeof(myArray); i++) {
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printByte(*(p + i));
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printString("\r\n");
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_delay_ms(1000);
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}
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/* To use them: */
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char *stringPointer;
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/* Get the pointer to the string you want from PROGMEM */
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stringPointer = (char *) pgm_read_word(&stringIndex[0]);
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printString_Progmem(stringPointer);
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/* or */
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stringPointer = (char *) pgm_read_word(&stringIndex[1]);
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printString_Progmem(&stringPointer[0]);
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/* or */
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printString_Progmem(PSTR("And this string got inlined.\r\n"));
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while (1) {
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printData_Progmem(myData, sizeof(myData) / sizeof(myData[0]));
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printString("\r\n");
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_delay_ms(1000);
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} /* End event loop */
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return 0; /* This line is never reached */
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}
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