This KBA describes how to debug your board and project in case you are experiencing "the device is not responding" issue when connecting the BGTool to your NCP target device.
The "not responding" error is received when BGTool is not able to communicate with the module using BGAPI messages over the UART interface. Normally when you click "connect" on BGTool: BGTool will try to read the BT device address of the target device. if there's no response, then you get the "not responding" popup.
The issue might be caused by:
The easiest method to be used in radio boards: flash a pre-built NCP-empty demo to the board. Since the demos are already tested and come with all the required configurations to be used as it is.
If you are using a custom board please Verify that the UART settings in your firmware align correctly with your custom board. In case you are not using the VCOM, make sure it is disabled in the hal-config.h file. If possible check with a logic analyzer or probe that the UART lines are correctly connected in your custom board.
Verify that the configuration of your device matches the one you are using in the BGTool, by default the BGTool uses a 115200 baud rate and no flow control.
You can check the device VCOM settings using the console in Studio, following this article KBA_BT_1208: Using virtual COM port (VCOM)
The default settings are: baud rate 115200, flow control = "auto".
If you radio board is unresponsive might be caused by a lack of bootloader. Please add the gecko bootloader to your device and project. Follow this article: KBA_BT_0603: Adding Gecko Bootloader to Bluetooth projects
It might also happen that BGTool simply gets out of sync (e.g. due to UART buffer overflow), and it cannot find the beginning of the BGAPI packets. There is no special character at the beginning of the packets, so it cannot resynchronize. In this case resetting the device and BGTool may help.
Sometimes just resetting the device is not enough, so unplugging and replugging the USB cable and power cycling your device is recommended.