I changed USB ports twice, restarting the operating system each time. The ST-Link is directly connected to the USB hub without a USB hub, which it has been all along. Using the Target > Option Bytes utility in ST-Link v4.5.0, I set Pages 58-63 to have Write Protection as shown in Li YiFan's link above. The screen shot from the ST-LINK > Printf via SWO viewer utility in St-Link is shown below. It does to indicate the baud rate. How else can I check the baud rate and observe the hex displaying mode?








. The log picture you upload is Blurred, please send us a new one. BTW, could you send us a photo how you connected OpenIMU330BI with your computer. And if you could change a PC or USB port and test again?