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STM32F0 I2C Example code

kasun_duminda92
Associate III
Posted on July 26, 2013 at 04:06

I have been trying to make a slave I2C device communicate with my STM32F0 board, with no success. Can anyone give me an example code to config, init and send and receive data through the I2C bus.

15 REPLIES 15
sanjib
Associate III
Posted on May 28, 2014 at 14:40

Hi did you solve your problem if yes please send me the sample code for i2c stm32f030

chen
Associate II
Posted on May 28, 2014 at 15:07

Hi

The standard peripheral library has I2C examples :

http://www.st.com/web/catalog/tools/FM147/CL1794/SC961/SS1743/PF257884

sanjib
Associate III
Posted on May 28, 2014 at 15:16

now im trying in this way.. but something its wrong.. on a terminal im getting only ''error2''.. any ideas? ;)


 #include ''stm32f0xx.h''
#include ''stm32f0xx_rcc.h''
#include ''stm32f0xx_gpio.h''
#include ''stm32f0xx_usart.h''
#include ''stm32f0xx_i2c.h''
#include <
stdio.h
>
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
I2C_InitTypeDef I2C_InitStructure;
#define MPU6050_RA_WHO_AM_I 0x75
#define Slave_address 0x68
#define mpu6050_FLAG_TIMEOUT ((uint32_t)0x1000)
#define mpu6050_LONG_TIMEOUT ((uint32_t)(500 * mpu6050_FLAG_TIMEOUT))
void USART_send( unsigned char data){
while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
USART_SendData(USART1, data);
}
void USART_print(char* StringPtr){
while(*StringPtr != 0x00){
USART_send(*StringPtr);
StringPtr++;}
}
void frej(uint8_t value)
{
int maska=0x01;
int i;
for(i=7;i>=0;i--){
int l = (((int)value)>>i)&maska;
char t = (char)(l+48);
USART_send(t);
}
USART_send(' ');
}
uint8_t ReadReg(uint8_t RegName)
{
uint8_t mpu6050_BufferRX[2] ={0,0};
uint8_t tmp = 0;
uint32_t DataNum = 0;
int mpu6050_Timeout = 0;
/* Test on BUSY Flag */
mpu6050_Timeout = mpu6050_LONG_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_ISR_BUSY) != RESET)
{
if((mpu6050_Timeout--) == 0) USART_print('' error1 '');
}
/* Configure slave address, nbytes, reload, end mode and start or stop generation */
I2C_TransferHandling(I2C1, Slave_address, 1, I2C_SoftEnd_Mode, I2C_Generate_Start_Write);
/* Wait until TXIS flag is set */
mpu6050_Timeout = mpu6050_LONG_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_ISR_TXIS) == RESET)
{
if((mpu6050_Timeout--) == 0) USART_print('' error2 '');
}
/* Send Register address */
I2C_SendData(I2C1, (uint8_t)RegName);
/* Wait until TC flag is set */
mpu6050_Timeout = mpu6050_LONG_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_ISR_TC) == RESET)
{
if((mpu6050_Timeout--) == 0) USART_print('' error3 '');
}
/* Configure slave address, nbytes, reload, end mode and start or stop generation */
I2C_TransferHandling(I2C1, Slave_address, 1, I2C_AutoEnd_Mode, I2C_Generate_Start_Read);
/* Reset local variable */
DataNum = 0;
/* Wait until all data are received */
while (DataNum != 1)
{
/* Wait until RXNE flag is set */
mpu6050_Timeout = mpu6050_LONG_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_ISR_RXNE) == RESET)
{
if((mpu6050_Timeout--) == 0) USART_print('' error4 '');
}
/* Read data from RXDR */
mpu6050_BufferRX[DataNum]= I2C_ReceiveData(I2C1);
/* Update number of received data */
DataNum++;
}
/* Wait until STOPF flag is set */
mpu6050_Timeout = mpu6050_LONG_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_ISR_STOPF) == RESET)
{
if((mpu6050_Timeout--) == 0) USART_print('' error5 '');
}
/* Clear STOPF flag */
I2C_ClearFlag(I2C1, I2C_ICR_STOPCF);
// !< Store LM75_I2C received data
//tmp = (uint16_t)(LM75_BufferRX[0] << 8);
//tmp |= LM75_BufferRX[0];
tmp = mpu6050_BufferRX[0];
// return a Reg value
return (uint8_t)tmp;
}
void LED_init(void){
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOC, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9|GPIO_Pin_8;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOC, &GPIO_InitStructure);
}
void USART_init(void){
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1,ENABLE);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource10, GPIO_AF_1);
//Configure pins: Rx and Tx --------------------------
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOA, &GPIO_InitStructure);
USART_InitStructure.USART_BaudRate = 9600;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
USART_InitStructure.USART_StopBits = USART_StopBits_1;
USART_InitStructure.USART_Parity = USART_Parity_No;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
USART_Init(USART1, &USART_InitStructure);
USART_Cmd(USART1,ENABLE);
}
void I2C_init(void){
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
/* Configure the I2C clock source. The clock is derived from the HSI */
RCC_I2CCLKConfig(RCC_I2C1CLK_HSI);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_1);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_1);
//Configure pins: SCL and SDA ------------------
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
GPIO_Init(GPIOB, &GPIO_InitStructure);
I2C_InitStructure.I2C_AnalogFilter = I2C_AnalogFilter_Enable;
I2C_InitStructure.I2C_DigitalFilter = 0x00;
I2C_InitStructure.I2C_OwnAddress1 = 0x00; // MPU6050 7-bit adress = 0x68, 8-bit adress = 0xD0;
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
//I2C_InitStructure.I2C_Timing = 0xA0120227;
I2C_InitStructure.I2C_Timing = 0x20310A0D;
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
I2C_Init(I2C1, &I2C_InitStructure);
I2C_Cmd(I2C1, ENABLE);
}
int main(void)
{
LED_init();
USART_init();
I2C_init();
int i=0;
while(1)
{
while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET); // Wait for Empty
ReadReg(MPU6050_RA_WHO_AM_I);
for(i=0;i<10000000;i++);
/*
int i=0;
if(USART_ReceiveData(USART1)=='x'){
GPIO_SetBits(GPIOC, GPIO_Pin_8);
}
for(i=0;i<1000000;i++);
GPIO_ResetBits(GPIOC, GPIO_Pin_8);
for(i=0;i<1000000;i++);
*/
}
}

sanjib
Associate III
Posted on May 29, 2014 at 12:11 OK,I found the problem. Flag I2C_ISR_TXIS did not get because the device on the i2c did not respond to the sent address. Need to convert the Slave address to 7 bits.

(SlaveAddr & 0x7f) << 1

prashanth
Associate II
Posted on August 01, 2014 at 12:27

Hi das,

Can you please share your working I2C code. It would be helpful for me to change that code to work on RTC. Currently, I am not able to read data from the RTC :(

Thnaks in advance

Prashanth 

sanjib
Associate III
Posted on November 29, 2014 at 06:45

The original post was too long to process during our migration. Please click on the provided URL to read the original post. https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I6m9&d=%2Fa%2F0X0000000bv7%2F.YRaJIZguQG9QudgUkVmwIegaJ9JCDIMlsZ2qAAGegg&asPdf=false
mukulmohalthere
Associate II
Posted on April 12, 2015 at 10:05

hii,

if you were able to run your i2c of stm32f030 can you please do send me the code as i am trying to run the i2c and it is showing same and wrong data on each changed data also

vikramtathe007
Associate
Posted on March 09, 2016 at 09:49

Hi,

can you share STM32F0 I2C Example code project?

or can you share following header files with me?

 #include ''stm32f0xx.h''

#include ''stm32f0xx_rcc.h''

#include ''stm32f0xx_gpio.h''

#include ''stm32f0xx_usart.h''

#include ''stm32f0xx_i2c.h''

Thanks,

Vikram

Posted on March 09, 2016 at 13:39

Those would be part of the STM32F0 Standard Peripheral Library, why wouldn't you just download that?

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