[SOLVED] AT24C256 not working write mode

[mi14chal]

I'm having a problem with AT24C256, because I cannot save my data there. I wrote simple code to read and to write some data to AT24C256:

void eepromWriteByte(unsigned char addr, unsigned int eepromAddr, unsigned char byte)
{
	i2c0Start();
	i2c0SetAddress(addr);
	i2c0Send(eepromAddr >> 8);   // MSB
	i2c0Send(eepromAddr & 0xFF); // LSB
	i2c0Send(byte);
	i2c0Stop();
	delay_ms(20);
}
 
unsigned char eepromReadByte(unsigned char addr, unsigned int eepromAddr)
{
	i2c0Start();
	i2c0SetAddress(addr);
	i2c0Send(eepromAddr >> 8);   // MSB
	i2c0Send(eepromAddr & 0xFF); // LSB
	i2c0Start();
	i2c0SetAddress(addr | 0x01);
	unsigned char data = i2c0ReceiveNOACK();
	i2c0Stop();
	return data;
}


eepromWriteByte(ADDREEPROM, 0, 0xDE);
eepromWriteByte(ADDREEPROM, 1, 0xAD);
 
uint8_t i1 = eepromReadByte(ADDREEPROM, 0); 
uint8_t i2 = eepromReadByte(ADDREEPROM, 1);

But when I'm using this code for writing not work correctly, b/c when I try to save some data, and then try to read it I always get a value 0xFF. And my question is where is a problem? I only want to add I connected pin WP to gnd, and I don't know what could be a problem. And I2C frequency is 100kHz.

 

[alexan_e]

What is the value of ADDREEPROM ?

 

[mi14chal]

#define ADDREEPROM 0x50

 

[alexan_e]

That doesn't seem right, according to the manual (assuming A1=A0=0) the address should be

10100000 for write (0xA0)
10100001 for read (0xA1)

 

[mi14chal]

Oh thanks now it works. I used an example code from another website and I thought there was a good address so I didn't check it. Thanks again for helping.