Hi all,i tested two method of I2C transmit and resulted as follow.Method 1 : HAL_I2C_Master_Transmit_DMA(&hi2c1, 0x4E, &Data_M[0], 4); Nothing come out at the logic analyserMethod 2 : HAL_I2C_Master_Transmit(&hi2c1, 0x4E, &Data_M[0], 4,1000); Data co...