Question
I2C EEPROM Transmittiong and Receiving
Posted on March 21, 2013 at 11:55
Hi,
I am trying to send Datas to a 24C128 EEPROM via I2C interface of an STM32F4 Discovery. The problem is that I am not receiving the same value I am writing into the EEPROM. I am trying to write 0x05 into 0x00 address but when I run the program I get 0xA1 instead. And if I debug the code step by step I get 0xFF on reception. Couldnt find out what's wrong. Here is my code.#include ''stm32F4xx.h''#include ''stm32f4xx_gpio.h''#include ''stm32f4xx_i2c.h''#define I2C1_SLAVE_ADDRESS7 0xA0 // EEPROM I2C Address#define ClockSpeed 200000 // 200 KHzuint8_t a=0;void I2CInit(void);void I2C1_WriteDeviceRegister(uint8_t , uint8_t , uint8_t );uint8_t I2C_ReadDeviceRegister(uint8_t , uint8_t );int main(void){ I2CInit(); /*----- Transmission Phase -----*/ I2C1_WriteDeviceRegister(0xA0 , 0x00 , 0x05); /*----- Reception Phase -----*/ a=I2C_ReadDeviceRegister(0xA0 , 0x00); while(1); }void I2CInit(void){ GPIO_InitTypeDef GPIO_InitStructure; I2C_InitTypeDef I2C_InitStructure; /* Enable GPIO clock */ RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE); /* Enable UART clock */ RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE); GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_I2C1); GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_I2C1); GPIO_InitStructure.GPIO_OType = GPIO_OType_OD; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_9; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOB, &GPIO_InitStructure); I2C_InitStructure.I2C_ClockSpeed = ClockSpeed; 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; /* Enable I2C */ I2C_Cmd(I2C1, ENABLE); I2C_Init(I2C1, &I2C_InitStructure);}/*************************/void I2C1_WriteDeviceRegister(uint8_t DeviceAddr, uint8_t RegisterAddr, uint8_t RegisterValue){/* Send I2C1 START condition */ I2C_GenerateSTART(I2C1, ENABLE); /* Test on I2C1 EV5 and clear it */ while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT)); /* Send EEPROM slave Address for write */ I2C_Send7bitAddress(I2C1, DeviceAddr, I2C_Direction_Transmitter); /* Test on I2C1 EV6 and clear it */ while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED)); /* Send I2C1 EEPROM internal address */ I2C_SendData(I2C1, RegisterAddr); /* Test on I2C1 EV8 and clear it */ while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED)); /* Send I2C1 EEPROM data */ I2C_SendData(I2C1, RegisterValue); /* Test on I2C1 EV8 and clear it */ while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED)); /* Send I2C1 STOP Condition */ I2C_GenerateSTOP(I2C1, ENABLE);}/****************************/uint8_t I2C_ReadDeviceRegister(uint8_t DeviceAddr, uint8_t RegisterAddr){ uint8_t tmp; /* Send I2C1 START condition */ I2C_GenerateSTART(I2C1, ENABLE); /* Test on I2C1 EV5 and clear it */ while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT)); /* Send EEPROM slave Address for write */ I2C_Send7bitAddress(I2C1, DeviceAddr, I2C_Direction_Transmitter); /* Test on I2C1 EV6 and clear it */ while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED)); /* Send I2C1 EEPROM internal address */ I2C_SendData(I2C1, RegisterAddr); /* Test on I2C1 EV8 and clear it */ while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED)); /* Regenerate a start condition */ I2C_GenerateSTART(I2C1, ENABLE); /* Test on I2C1 EV5 and clear it */ while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT)); /* Transmit the slave address and enable writing operation */ I2C_Send7bitAddress(I2C1, DeviceAddr, I2C_Direction_Receiver); /* Test on I2C1 EV6 and clear it */ while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED)); /* End the configuration sequence */ I2C_GenerateSTOP(I2C1, ENABLE); /* Load the register value */ tmp = I2C_ReceiveData(I2C1); /* Return the read value */ return (tmp);}#ifdef USE_FULL_ASSERT/** * @brief Reports the name of the source file and the source line number * where the assert_param error has occurred. * @param file: pointer to the source file name * @param line: assert_param error line source number * @retval None */void assert_failed(uint8_t* file, uint32_t line){ /* User can add his own implementation to report the file name and line number, ex: printf(''Wrong parameters value: file %s on line %d\r\n'', file, line) */ /* Infinite loop */ while (1) { }}#endif