Posted on December 06, 2011 at 18:19Hello. I have a device connected to stm32 through I2C1. Am I right initialize it?
&sharpdefine DEV_ADDR 0x53
uint8_t I2C_ByteRead(uint8_t Addr)
{
uint8_t tmp;
while(I2C_GetFlagStatus(I2CG, I2C_FLAG_BUSY)); // While the bus is busy
I2C_GenerateSTART(I2CG, ENABLE); // Send START condition
while(!I2C_CheckEvent(I2CG, I2C_EVENT_MASTER_MODE_SELECT)); // Test on EV5 and clear it
I2C_Send7bitAddress(I2CG, DEV_ADDR<< 1, I2C_Direction_Transmitter); // Send address for write (SAD+W)
while(!I2C_CheckEvent(I2CG, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED)); // Test on EV6 and clear it
I2C_SendData(I2CG, Addr); // Send the internal address to read from: MSB of the address first
while(!I2C_CheckEvent(I2CG, I2C_EVENT_MASTER_BYTE_TRANSMITTED)); // Test on EV8 and clear it
I2C_GenerateSTART(I2CG, ENABLE); // Send STRAT condition a second time
while(!I2C_CheckEvent(I2CG, I2C_EVENT_MASTER_MODE_SELECT)); // Test on EV5 and clear it
I2C_Send7bitAddress(I2CG, DEV_ADDR<< 1, I2C_Direction_Receiver); // Send address for read
while(!I2C_CheckEvent(I2CG,I2C_EVENT_MASTER_BYTE_RECEIVED)); // Test on EV6 and clear it
tmp=I2C_ReceiveData(I2CG);
I2C_AcknowledgeConfig(I2CG, DISABLE);
I2C_GenerateSTOP(I2CG, ENABLE); // Send STOP Condition
return tmp;
}
void I2CG_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
I2C_InitTypeDef I2C_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO , ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
// I2CG clock enable
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2CG, ENABLE);
// GPIOB clock enable
// I2CG SCL and SDA configuration
GPIO_InitStructure.GPIO_Pin = SCL|SDA;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);
// GPIO_PinAFConfig(GPIOC,SCLSource,GPIO_AF_I2CG);
// GPIO_PinAFConfig(GPIOC,SDASource,GPIO_AF_I2CG);
// Enable I2CG reset state
RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2CG, ENABLE);
// Release I2CG from reset state
RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2CG, DISABLE);
// I2C_DeInit(I2C1);
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 = ClockSpeed;
I2C_AcknowledgeConfig(I2CG, ENABLE);
I2C_Init(I2CG, &I2C_InitStructure);
I2C_Cmd(I2CG, ENABLE);
}
I can't read a device ID(0xE5)
if(I2C_ByteRead(0x00)!=0xE5)
I always stuck at
while(!I2C_CheckEvent(I2CG, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED)); in fuction ''
I2C_ByteRead''
Please help me understand what I'm doing wrong.
#stm32 #i2c
