Nuvoton NuTool - BLE ATCMD is a development module that supports UART-to-BLE transmissions. Suppose the host side initially does not support the BLE function. In that case, it can become a BLE Peripheral by connecting to BLE ATCMD through the UART interface and then communicating with a remote cell phone or host side BLE Central.

NuTool - BLE ATCMD has two functional modes, command mode and data mode, and the host side can control which mode the BLE ATCMD is in through specific GPIOs. 

At Command Mode:

The host side can control various parameters settings of BLE ATCMD, such as UART baud rate, BLE advertising device name, BLE advertising or connection interval, BLE PHY bitrate, BLE transmit power, and whether to advertise or not, etc. 

At Data Transmission Mode:

Both sides can perform data transmission in both directions when the remote BLE Central connects to the host side. First, the host side transmits data to the BLE ATCMD through the UART interface, and then the BLE ATCMD transmits data to the remote BLE Central through the BLE. And vice versa. 

NuTool - BLE ATCMD also provides Android, iOS Apps and source codes, allowing users to quickly test and verify the functionality and develop their Apps.

The following is the architecture of NuTool - BLE ATCMD.