Posted on April 14, 2012 at 11:33
Hi,
I am having problem with I2C on STM32F100C8 .
I'm not sure if its my code or the I2C peripheral giving the problem.After initialization the code is getting stuck in test on EV6
where I am getting i2c last event as 0x30400(I2C->SR1=0x400 and I2C->SR2=3 and the event I'm expecting is 0x70082(I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED).
On the oscilloscope I see that SCL and SDA are high initially and go low after start condition and then SDA goes high and remains high while SCL continues to remain low when I send the device address.
Could someone help me to debug this better,Thanks
Here is my code snippet,
void
MMA8453Q_I2C_InitBusPins(
void
)
{
I2C_InitTypeDef I2C_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
/* Enable I2C and GPIO clocks */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO | RCC_APB2Periph_GPIOB,ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
GPIO_PinRemapConfig(GPIO_Remap_I2C1, ENABLE);
/* Configure I2C pins: SCL and SDA */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_8;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
GPIO_Init(ACC_I2C_Port, &GPIO_InitStructure);
/* I2C configuration */
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
I2C_InitStructure.I2C_OwnAddress1 = 0x00;
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
I2C_InitStructure.I2C_ClockSpeed = 100000;
/* I2C Peripheral Enable */
I2C_Cmd(I2C1, ENABLE);
/* Apply I2C configuration after enabling it */
I2C_Init(I2C1, &I2C_InitStructure);
}
void
MMA8453Q_I2C_BufferRead(u8 slAddr, u8* pBuffer, u8 ReadAddr, u16 NumByteToRead)
{
/* 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 MMA8453Q_Magn address for write */
I2C_Send7bitAddress(I2C1, ACC_I2C_ADDRESS_WRITE, I2C_Direction_Transmitter);
/* Test on EV6 and clear it */
while
(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
//code stuck here
}
unsigned
char
MMA8453Q_I2C_Init(
void
){
unsigned
char
i;
MMA8453Q_I2C_InitBusPins();
MMA8453Q_I2C_BufferRead(ACC_I2C_ADDRESS,&i,ACC_WHO_AM_I,1);
if
(i != 0x1a)
return
(0);
return
(1);
}
