HAL_I2C_Master_Transmit_IT(&hi2c1,e,&c,1); HAL_I2C_Slave_Receive(&hi2c2,&d, 1, 1000);In the above case, it was confirmed that I2C communication works well. HAL_I2C_Master_Transmit(&hi2c1,e,&c,1,1000); HAL_I2C_Slave_Receive(&hi2c2,&d, 1, 1000);H...