Atmega8A uart spi eeprom - c++

Question

everyone, I want to write and store my string at spi eeprom, then read back from spi eeprom and display in terminal through uart. I already follow the step in [1]: http://ww1.microchip.com/downloads/en/DeviceDoc/21822E.pdf . But it seem that it can only display one letter. I don't know if the other letter is save in spi eeprom or not. I hope someone can help me.
I am using:
chip:Atmega8a
software:avr studio 5
terminal: Bray terminal.
#include <avr/io.h>
#include <util/delay.h>
void serial_init(void)
{
UBRRH = 0x00;
UBRRL = 95;
UCSRB = (1 << RXEN) | (1 << TXEN) | (1<<RXCIE);
UCSRC = (1<<URSEL)|(1<<USBS)|(3<<UCSZ0)|(1 << UCSZ1);
}
void SPI_MasterInit(void)
{
DDRB = 0b00101100;
DDR_SPI = (1<<DD_MOSI)|(1<<DD_SCK)|(1<<DD_SS);
SPCR = 0b01010000;
SPSR = 0b00000001;
}
char spi_transfer(volatile char data)
{
SPDR = data;
while(!(SPSR & (1<<SPIF)));
{
}
return SPDR;
}
void SPI_MasterTransmit(unsigned long data)
{
unsigned long address;
DDR_SPI &= ~(1<<DD_SS); //ss goes low
spi_transfer(WREN); //enable write operation
DDR_SPI |= (1<<DD_SS); //ss goes high
_delay_ms(10);
DDR_SPI &= ~(1<<DD_SS); //ss goes low
spi_transfer(WRITE); // write data to memory
spi_transfer(address>>8); // address MSB first
spi_transfer(address);
spi_transfer(data); // send lsb
DDR_SPI |= (1<<DD_SS); //ss goes high
}int resetEEPROM()
{
DDR_SPI &= ~(1<<DD_SS); // Select EEPROM
spi_transfer(WREN); // Send WRITE_ENABLE command
DDR_SPI |= (1<<DD_SS); // Release EEPROM
DDR_SPI &= ~(1<<DD_SS); // Select EEPROM again after WREN cmd
spi_transfer(WRDI); // send CHIP_ERASE command
DDR_SPI |= (1<<DD_SS); // Release EEPROM
return 0;
} // END eraseEEPROM()
unsigned long SPI_MasterReceive(unsigned long address) //terima data //read address
{
unsigned long data;
DDR_SPI &= ~(1<<DD_SS); //ss goes low
spi_transfer(READ); //enable write operation
spi_transfer(address>>8); // address MSB first
spi_transfer(address);
data = spi_transfer(0xff);
DDR_SPI |= (1<<DD_SS); //goes high
return data;
}
int main(void)
{
long int data;
unsigned long address;
serial_init();
SPI_MasterInit();
resetEEPROM();
data = Usart_Receive();
while (1)
{
if (Usart_Receive() == '.')
{
USART_Print("\r\nStore\r\n");
SPI_MasterTransmit(data); //store in spi eeprom
}
if (Usart_Receive() == '>')
{
USART_Print("\nout \r\n");
data = SPI_MasterReceive(address); //read data from the memory
Usart_Transmit(data);
}
}
return 0;
}

Answer 1

There is a way to write more than one byte to the EEPROM at once, but your code does not do that. Instead, you are writing one byte per write operation, and always at the same address. You are overwriting any previous bytes with each new one.
If you want to store more than one byte, you need to change the address as you write, or change the way you are writing to more than one byte at a time. (Note that you can only write multiple bytes if they are the same page of EEPROM memory.)

Answer 2

Perhaps a circular buffer?
Here are my Circular Buffer code. Based on this http://www.rn-wissen.de/index.php/UART_mit_avr-gcc
#include <avr/io.h>
#include <fifo.h>
#define FIFOBUF_SIZE 128
uint8_t fifobuf[FIFOBUF_SIZE];
fifo_t fifo;
ISR (USART_RXC_vect)
{
_inline_fifo_put(&fifo, UDR);
}
void serial_init(void)
{
cli();
UBRRH = 0x00;
UBRRL = 95;
UCSRB = (1 << RXCIE) | (1 << RXEN) | (1 << TXEN);
UCSRC = (1<<URSEL)|(1<<USBS)|(3<<UCSZ0);
sei();
}
void fifo_init (fifo_t *f, uint8_t * buffer, const uint8_t size)
{
f-> count = 0;
f-> pread = f-> pwrite = buffer;
f-> read2end = f-> write2end = f-> size = size;
}
static inline int Usart_Transmit (const uint8_t c)
{
PORTD= 0b00000100; //RTS Enable
while ((UCSRA & (1 << UDRE)) ==0) {};
UDR = c;
PORTD= 0b00000000; //RTS Enable
return 1;
}
int main(void)
{
unsigned long data;
unsigned long address;
fifo_init(&fifo, fifobuf, FIFOBUF_SIZE);
serial_init();
while (1)
{
SPI_MasterInit();
resetEEPROM();
SPI_MasterTransmit(Usart_Receive());
_delay_ms(100);
if (fifo.count > 0) //; fifo.count >8 ; fifo.count
{
Usart_Transmit(_inline_fifo_get(&fifo));
}
data = SPI_MasterReceive(address); //read data from the memory
_delay_ms(100);
Usart_Transmit(data);
}
return 0;
}
it Came out all of the letter, but not follow the sequence. Example like this " bfabeaabbfcabf ", I am only type " abcdef "
And can you show me how to set the EEPROM address in spi EEPROM. Like e.g. show me some link or example about this spi EEPROM address. I ask for your Kindness to help me about this because I have been about 2 months searching on the internet, there only few examples on how to handle spi EEPROM address. Mostly I just found about ATmega EEPROM, LTD. And all of Them are not give me a good result. Thank in advance for your time. :)