Posted on May 17, 2011 at 13:23Thanks guyvo67!
I checked my scope with a sec/div setting of like 25 microseconds. I can clearly see all the data bytes/ address bytes etc. on the SDA and SCL clocking. There is an ACK after every byte as per the scope results. I guess my 24AA16 EEPROM doesnot recognize the ''internal'' address which i send?
My read returns FF. Code snippet is as follows:-
/* Enable peripheral clocks --------------------------------------------------*/
/* GPIOB Periph clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
/* I2C1 Periph clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
/* Configure I2C1 pins: SCL and SDA ----------------------------------------*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
GPIO_Init(GPIOB, &GPIO_InitStructure);
I2C_InitTypeDef I2C_InitStructure;
/* I2C configuration */
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
I2C_InitStructure.I2C_OwnAddress1 = I2C1_SLAVE_ADDRESS7;
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
I2C_InitStructure.I2C_ClockSpeed = 50000;
/* I2C Peripheral Enable */
I2C_Cmd(I2C1, ENABLE);
/* Apply I2C configuration after enabling it */
I2C_Init(I2C1, &I2C_InitStructure);
//result = ex_i2c_open(0,0);
User_Print(''\r\nEKA Systems'');
//readEEPROM()
writeEEPROM();
readEEPROM();
/**********************************************************/
//Write and Read functions :
void writeEEPROM()
{
/****************** Write a byte to the EEPROM ****************/
/* Send START condition */
I2C_GenerateSTART(I2C1, ENABLE);
/* Test on EV5 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));
/* Send EEPROM address for write */
I2C_Send7bitAddress(I2C1, 0xA0, I2C_Direction_Transmitter);
/* Test on EV6 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
/* Clear EV6 by setting again the PE bit */
I2C_Cmd(I2C1, ENABLE);
/* Send the EEPROM's internal address to write to */
I2C_SendData(I2C1, EEPROM_INTERNAL_ADDRESS);
/* Test on EV8 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
/* Send the byte to be written */
I2C_SendData(I2C1, 0xBE);
/* Test on EV8 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
/* Send STOP condition */
I2C_GenerateSTOP(I2C1, ENABLE);
}
void readEEPROM()
{
/**************** Read a byte from the EEPROM ****************/
/* While the bus is busy */
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));
/* Send START condition */
I2C_GenerateSTART(I2C1, ENABLE);
/* Test on EV5 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));
/* Send EEPROM address for write */
I2C_Send7bitAddress(I2C1, 0xA0, I2C_Direction_Transmitter);
/* Test on EV6 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
/* Clear EV6 by setting again the PE bit */
I2C_Cmd(I2C1, ENABLE);
/* Send the EEPROM's internal address to write to */
I2C_SendData(I2C1, EEPROM_INTERNAL_ADDRESS);
/* Test on EV8 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
/* Send START condition a second time */
I2C_GenerateSTART(I2C1, ENABLE);
/* Test on EV5 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));
/* Send EEPROM address for read */
I2C_Send7bitAddress(I2C1, 0xA0, I2C_Direction_Receiver);
/* Test on EV6 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));
while(!I2C_GetFlagStatus(I2C1,I2C_FLAG_RXNE));
/* Byte to be read */
/* Test on EV7 and clear it */
if(I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED))
{
/* Read a byte from the EEPROM */
sprintf(tempStr,''\r\nEEPROM contains 0X%04X'',I2C_ReceiveData(I2C1));
User_Print(tempStr);
}
/* Disable Acknowledgement */
I2C_AcknowledgeConfig(I2C1, DISABLE);
/* Send STOP Condition */
I2C_GenerateSTOP(I2C1, ENABLE);
}
