I need an example code for I2C programming to interface stm32f4 with at24c512 eeprom

[Nirmalaa devi]

Posted on April 03, 2017 at 08:53

#include 'stm32f4xx.h'

#include 'stdio.h'

#define SLAVE_ADDRESS 0xA0

unsigned char read;char arr[3]= 'NV';char data[3];

void delay_ms(int d)

{ int i,j; for(i=0;i<d;i++) for(j=0;j<32;j++);}

void uart3_init()

{ RCC->AHB1ENR|=1<<1; // GPIOB clock enable for portB RCC->APB1ENR|=1<<18; //USART3 clock enable

GPIOB->MODER|=1<<21|1<<23|1<<25; //Alternate func for Mode 10,11 &12

GPIOB->OTYPER|=0<<10|0<<11|0<<12; // output push_pull mode for 10,11,12 GPIOB->OSPEEDR|= 1<<18|1<<16; //1<<21|1<<23|1<<25; // fast speed mode 50MHz GPIOB->PUPDR|= 1<<20|1<<22|1<<24; // pull_up mode for 10,11,12 GPIOB->AFR[1]|=1<<8|1<<9|1<<10|1<<13|1<<14|1<<12|1<<18|1<<17|1<<16; // alternate pin func for AF7 in usart3

USART3->CR1|=1<<13; // USART3 enable

USART3->BRR=0x16C; //115200 USART3->CR1|=1<<3|1<<2; // TX& RX enable for USART3 RCC->AHB1ENR |=1<<3; // GPIOD clk enable GPIOD->MODER |= 1<<30|1<<28|1<<26|1<<24; GPIOD->OSPEEDR |= 1<<31|1<<29|1<<27|1<<25;

}

/*========================================================================================*/void I2C1_init(){ RCC->APB1ENR |= ((uint32_t)0x00200000); //I2C1 RCC->AHB1ENR |= ((uint32_t)0x00000002); //GPIOB GPIOB->MODER |=0x000A0280; //PB8& PB9 GPIOB->OTYPER|=0x00000300; // open drain GPIOB->OSPEEDR|= 0x000A00C0; //0x00009000; //0x0000A0C0; // 50MHz speed GPIOB->PUPDR |= 0x00050100; // pull_up GPIOB->AFR[8 >> 0x03] |=0x004; GPIOB->AFR[9 >> 0x03] |=0x040;

I2C1->CR1|= 0X405; // ACK& PE enable

I2C1->CR2 = 0X2A; // 42Mhz speed I2C1->CCR = 0X8023; // Fast mode &dutycycle_2 I2C1->TRISE = 0x0D; // rise time I2C1->OAR1 = 0X40A0 ; //ACK write mode} /*========================================================================================*/

void EEPROM_write(uint8_t addr)//,unsigned char data)

{ int i;

I2C1->CR1 |=((uint16_t)0x401); // send START condition

while((I2C1->SR2 &0x02)); /* While the bus is busy */

I2C1->CR1 |=((uint16_t)0x0100); // send START condition delay_ms(5);

while(!((I2C1->SR1 & 0X01)&&(I2C1->SR2 & 0x03))); /* Test and clear in start condition,Busy flag and master mode */

I2C1->DR = SLAVE_ADDRESS; /* Send EEPROM address for write */ delay_ms(5); while(!((I2C1->SR1 & 0x82)&&(I2C1->SR2 & 0x07))); /* Check Tx is empty or not 7 clear,Busy flag set and adrr byte for R/W */ I2C1->OAR1 |=0x00A0; I2C1->DR = 0x00; delay_ms(5);

for(i=0;i<3;i++)

{ while(!((I2C1->SR1 & 0x84)&&(I2C1->SR2 & 0x07))); /* master mode and Tx and Busy flag set and clear */ I2C1->DR = arr[i]; //data delay_ms(5); } GPIOD->BSRRL|= 1<<12; // led 12 // I2C1->SR1 |= (uint16_t)~0x4000; //Clear AF flag I2C1->CR1 =((uint16_t)0x0200); /*stop*/

//I2C1->CR1 = 0x601; /* I2C STOP condition*/

} /*========================================================================================*/void EEPROM_read(uint8_t addr){ int i=0; I2C1->OAR1 |=0x00A1;

I2C1->CR1 |=((uint16_t)0x401); // send START condition

// uint8_t addrh=(addr&0xff00)>>8; // uint8_t addrl= addr & 0x00ff;

while((I2C1->SR2 & 0x2)); /* While the bus is busy */

I2C1->CR1 |=((uint16_t)0x0100); // send START condition

delay_ms(5); while(!((I2C1->SR1 & 0X01)&&(I2C1->SR2 & 0x03))); /* Test and clear in start condition,Busy flag and master mode */ I2C1->DR = SLAVE_ADDRESS; /* Send EEPROM address for write */ // delay_ms(5);

while(!((I2C1->SR1 & 0x82)&&(I2C1->SR2 & 0x07))); /* Check Tx is empty or not 7 clear,Busy flag set and adrr byte for R/W */

I2C1->DR = 0x00;

delay_ms(5);

while(!((I2C1->SR1 & 0x84)&&(I2C1->SR2 & 0x07))); /* master mode Tx and Busy flag set and clear */

I2C1->CR1 |=((uint16_t)0x0100); // send START condition

while(!((I2C1->SR1 & 0X01)&&(I2C1->SR2 & 0x03))); /* Test and clear in start condition,Busy flag and master mode */

// delay_ms(5); I2C1->DR =0xA1; while(!((I2C1->SR1 & 0X02)&&(I2C1->SR2 & 0x03))); /* Test and clear in start condition,Busy flag and master mode */ while(((I2C1->SR1 & 0x40)&&(I2C1->SR2 & 0x03)));/* Test and clear in start condition,Busy flag and master mode */ data[2]=I2C1->DR; USART3->DR=I2C1->DR; while(((I2C1->SR1 & 0x40)&&(I2C1->SR2 & 0x03))); /* Test and clear in start condition,Busy flag and master mode */

USART3->DR=I2C1->DR;

GPIOD->BSRRL |= 1<<14; //led 14

I2C1->CR1 &= (uint16_t)~((uint16_t)0x0400); /* Disable the acknowledgement */

I2C1->CR1 =((uint16_t)0x0200); /* Send STOP Condition */

}

/*========================================================================================*/int main(void){ int i=0; uart3_init(); printf('Init_Uart\r\n'); I2C1_init(); printf('I2C_Init..!\r\n'); EEPROM_write(0x00); printf('I2C_write..!\r\n'); delay_ms(5); EEPROM_read(0x00); printf('I2C_read..!\r\n'); GPIOD->BSRRL |= 1<<15;//led 15 for(i=0;i<3;i++) { printf('%c',data[i]); // while(!(USART3->SR & 0x80)); } while(1) { // printf('Hello..!\r\n'); }}int fputc(int ch, FILE *f){ USART3->DR = ch; while(!(USART3->SR & 0x80)); return ch;}

#ifdef USE_FULL_ASSERT

void assert_failed(uint8_t* file, uint32_t line){while (1);}#endif

============================================

this is my code but its not working i wont get any data 

[Imen.D]

Posted on April 03, 2017 at 13:06

Hi,

You can find

I2C_EEPROM

example intheSTM32F4 standard peripheral package, that can help you:

STM32F4xx_DSP_StdPeriph_Lib_V1.8.0\Project\STM32F4xx_StdPeriph_Examples\I2C\I2C_EEPROM

Also, if you need HAL example within STM32CubeF4 firmware package, you have this running example showing how to use the I2C: STM32Cube_FW_F4_V1.0\Projects\STM32469I_EVAL\Examples\I2C\I2C_EEPROM

https://community.st.com/0D50X00009XkW1qSAF

Hope this helps you.

Imen