SD Memory Card Library for AVR Microcontrollers

Note: I originally wrote this small library back in 2012 while working on my university project, Wave Audio Player with AVR Microcontrollers and an SD Card. I'm sharing it here as a way to preserve the memory and reflect on that time.

It is tested in CodeVisionAVR IDE with ATMEGA32A

How to Use

Include mega32.h and spi.h headers and then this header sd_lib.h

For example our microcontroller is ATmega32

#include <mega32.h>

#include <spi.h>

#include "sd_lib.h"

Init SPI Registers

SPCR=0x50;

SPSR=0x01;

Init SD Card

It returns 0 If it is initiated correctly

unsigned char  sd_init(void);

Finally use read_sd and read_sd functions to read data.

unsigned char  read_sd(unsigned long int  sector,unsigned char* buffer);

unsigned char  write_sd(unsigned long int sector,unsigned char* buffer);

Input is SD Card sector number and output is sector size buffer array.