我是新的I2C通讯。我检查了一些正在运行的代码。而且我用的功能自己用。但是我无法获得任何数据。我想知道I2C是否必须进行初始配置?问题出在哪里。这是我写的函数:
void GetI2CAccelerometer(uint8_t slaveAddress,uint8_t accelData[6])
{
// slaveAddress=0x68 (default address is written in datasheet)
HAL_I2C_Master_Transmit(&hi2c1,slaveAddress<<1,1,0x3B,1,200);
HAL_I2C_Master_Receive(&hi2c1,slaveAddress<<1,accelData,6,200);
HAL_I2C_Mem_Read(&hi2c1,(slaveAddress<<1)+1,0x3B,1,accelData,1,200);
// i tried this function too but not working
}
我用CubeMX创建了这个项目。这是初始的I2C配置,并且GPIO_A时钟线在另一个我未编写的功能中被激活:
static void MX_I2C1_Init(void)
{
hi2c1.Instance = I2C1;
hi2c1.Init.ClockSpeed = 100000;
hi2c1.Init.DutyCycle = I2C_DUTYCYCLE_2;
hi2c1.Init.OwnAddress1 = 208;
hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
hi2c1.Init.OwnAddress2 = 0;
hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
if (HAL_I2C_Init(&hi2c1) != HAL_OK)
{
Error_Handler();
}
}
首先,更好地使用DMA或IT数据交换。轮询不是很好,但是可以进行测试。
您必须将指针指向数据,而不是数据本身。好的做法是这样的:
void GetI2CAccelerometer(I2C_HandleTypeDef * hi2c, uint8_t slaveAddress, uint8_t * accelData, size_t size) {
uint8_t request = 0x3B;
// slaveAddress=0x68 (default address is written in datasheet)
// HAL_I2C_Master_Transmit(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size, uint32_t Timeout)
while (HAL_I2C_Master_Transmit(hi2c, slaveAddress << 1, (uint8_t*)request, 1, 200) != HAL_OK) {
// Use FreeRTOS vTaskDelay(1) and/or check errors here
// And check timeout or you will hang over here
}
//HAL_I2C_Master_Receive(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size, uint32_t Timeout)
while (HAL_I2C_Master_Receive(hi2c, slaveAddress << 1, accelData, size, 200) != HAL_OK) {
// Use FreeRTOS vTaskDelay(1) and/or check errors here
// And check timeout or you will hang over here
}
while (HAL_I2C_GetState(hi2c) != HAL_I2C_STATE_READY) {
// Use FreeRTOS vTaskDelay(1) and/or check errors here
// And check timeout or you will hang over here
}
}
然后按功能请求数据:
uint8_t accelData[6];
GetI2CAccelerometer(&hi2c1, 0x68, accelData, 6);
可以接受测试,但对生产不利。获取数据,然后重写以使用I2C DMA或IT。检查I2C总线上的错误,并进行一些枚举以从函数返回错误/状态。