Posted on November 22, 2011 at 23:46Well I have now created some code that I think looks ok from both the examples and things I have found around the internet. How ever I am always hitting the timeouts, either when checking I2C_EVENT_MASTER_MODE_SELECT or if I comment that part out, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED. I am watching these with breakpoints in Keil and they always hit.
I also can not see any activity on PB6 and PB7 (I realy should get a bus pirate)
I am hoping that it is something realy simple and that I am just not doing something that would be clear to someone with more experience. I am currently developing on the STM32L-Discovery.
Here is my current code...
#define I2C_SPEED 100000
#define I2C1_SLAVE_ADDRESS7 0x040
#define I2C_TIMEOUT 100000
GPIO_InitTypeDef GPIO_InitStructure;
I2C_InitTypeDef I2C_InitStructure;
/* PRIVATE */
int main(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
I2C_InitTypeDef I2C_InitStructure;
int TimeOut;
/*!< I2C Periph clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
/*!< SDA GPIO clock enable */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
/*!< SCL GPIO clock enable */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
/* Connect PXx to I2C_SCL */
GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_I2C1);
/* Connect PXx to I2C_SDA */
GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_I2C1);
/*!< Configure I2C SCL pin */
GPIO_InitStructure.GPIO_Pin = GPIO_PinSource6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_40MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/*!< Configure I2C SDA pin */
GPIO_InitStructure.GPIO_Pin = GPIO_PinSource7;
GPIO_Init(GPIOB, &GPIO_InitStructure);
I2C_DeInit(I2C1);
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
I2C_InitStructure.I2C_OwnAddress1 = 0x020;
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
I2C_InitStructure.I2C_ClockSpeed = I2C_SPEED;
I2C_Init(I2C1, &I2C_InitStructure);
/*ENABLE*/
I2C_Cmd(I2C1, ENABLE);
I2C_GenerateSTART(I2C1, ENABLE);
/* Check we can be master */
TimeOut = I2C_TIMEOUT;
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT))
{
TimeOut--;
if (TimeOut == 0)
{
return 1;
}
}
I2C_SendData(I2C1, 0x03); /*Set pin states*/
I2C_Send7bitAddress(I2C1, I2C1_SLAVE_ADDRESS7, I2C_Direction_Transmitter);
TimeOut = I2C_TIMEOUT;
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED))
{
TimeOut--;
if (TimeOut == 0)
{
I2C_GenerateSTOP(I2C1, ENABLE);
return 2;
}
}
return 1;
}
Any further help would be greatly apreciated.
