用STM32F051的I2C从模式做某模块的控制接口,通过主机读状态和写控制命令。
Eclips 环境,gcc编译器,相关源码如下:
#ifdef DEBUG_I2C_EN
#define DEBUG_I2C(...) printf(__VA_ARGS__)
#else
#define DEBUG_I2C(...)
#endif
void I2C_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
I2C_InitTypeDef I2C_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
// I2C port
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_1);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_1);
// I2C config
I2C_InitStructure.I2C_Timing = 0x00731012;
I2C_InitStructure.I2C_AnalogFilter = I2C_AnalogFilter_Enable;
I2C_InitStructure.I2C_DigitalFilter = 0x00;
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
I2C_InitStructure.I2C_OwnAddress1 = DEV_SLAVE_ADDR;
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
I2C_Init(I2C1, &I2C_InitStructure);
I2C_Cmd(I2C1, ENABLE);
I2C_StretchClockCmd(I2C1, DISABLE);
NVIC_InitStructure.NVIC_IRQChannel = I2C1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPriority = 2; // Low Medium Hight VeryHigh: 0 - 3
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
uint32_t temp = I2C_IT_STOPI |
I2C_IT_ADDRI |
I2C_IT_RXI |
I2C_IT_TXI;
I2C_ITConfig(I2C1, temp, ENABLE);
}
static uint8_t Instruct = 0;
static uint8_t Offset = 0;
static uint8_t MaxBytes = 0;
uint8_t *TxBuff;
uint8_t RxBuff[40];
void I2C1_IRQHandler(void)
{
uint8_t temp;
uint32_t status = I2C1->ISR;
DEBUG_I2C("I2C1->ISR: %08Xnr", status);
if(status & I2C_ISR_ADDR)
{ // I2C1 Address match event occurs
I2C_ClearITPendingBit(I2C1, I2C_ISR_ADDR);
if(status & I2C_ISR_DIR)
{ // I2C1: slave enters transmitter mode.
;
}
else
{ // I2C1: slave enters receiver mode.
Instruct = 1;
}
Offset = 0;
}
else if(status & I2C_ISR_RXNE)
{
I2C1->ISR |= I2C_ISR_TXE;
temp = I2C_ReceiveData(I2C1);
if(Instruct)
{ // Host Instruct
switch(temp)
{
case 0x00: // Get DevInfo
TxBuff = (uint8_t *)&DevInfo; // 24 bytes
MaxBytes = sizeof(DevInfo);
break;
case 0x18: // Get DevStatus
TxBuff = (uint8_t *)&DevStatus; // 8 bytes
MaxBytes = sizeof(DevStatus);
break;
default: break;
}
Instruct = 0;
}
RxBuff[Offset++] = temp;
}
else if(status & I2C_ISR_TXIS)
{
I2C1->ISR |= I2C_ISR_TXE;
if(Offset < MaxBytes)
{
I2C_SendData(I2C1, TxBuff[Offset++]);
}
else
{
I2C_SendData(I2C1, 0xFF);
}
}
else if(status & I2C_ISR_STOPF)
{
I2C_ClearITPendingBit(I2C1, I2C_ISR_STOPF);
DEBUG_I2C("I2C1 Host stop, Bytes: %dnr", Offset);
; // 指令解析
;
}
else
{
I2C_ClearITPendingBit(I2C1, 0x00003F38);
printf("I2C1 Unknown event occurs!nr");
}
}
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