Getting Started with Bluetooth Xpress
BGX modules provide a wireless link between other BGX modules and smartphones. BGX modules create a serial interface replacement using the custom Xpress streaming service. An embedded host transmits and receives data through UART RX and TX pins. Mobile apps can connect and communicate with BGX modules using the Xpress framework, which provides a simple API for BGX interaction.
The following video gives a quick overview of how this works:
Demo with a PC
The following hardware and software are needed to reproduce the steps in the video.
Note that the instructions below use a BGX13P evaluation board. All the same instructions can be followed using the BGX220P evaluation board and will deliver the same results.
- Evaluation board
- Virtual COM port driver for your PC
- BGX Commander Mobile App
See the following for additional example demos for using the BGX13:
BGX Commander Mobile Apps
BGX Commander is an app available for both iOS and Android devices. This app allows users to connect and communicate with BGX devices, exercising both the streaming interface and the Xpress command API through remote command execution. To install the app on your mobile device, go to the app store and search for 'BGX Commander'.
The app also provides an OTA service for users. Silicon Labs strongly encourages users to perform an OTA update on BGX evaluation boards at the start of evaluation, to ensure that the module supports all the latest features and functionality.
Also note that the mobile apps were built using the Xpress framework, which simplifies communication between BGX devices and mobile apps. The source code for BGX Commander, which includes the Xpress framework, is available on Github.
The BGX13P Evaluation Board
The BGX13P evaluation board provides a USB-to-serial interface that enables users to communicate with the on-board BGX13P through terminal programs. The board can also be connected to Silicon Labs EFM8 and EFM32 starter kits through the expansion header. This connectivity gives users the chance to prototype applications with embedded hosts.
Click here for more information about the Bluetooth Xpress Starter Kit.
Evaluating BGX13 with a Terminal Program
The BGX13P's CP2102N serial-to-USB interface device requires installation of a Virtual COM Port (VCP) driver.
Click here for CP2102N VCP drivers.
Once drivers are installed, a BGX13P evaluation board connected to a PC through the USB connection will appear as a comm port. This comm port can be opened in a terminal application and users can communicate with the on-board BGX13P through the terminal's interface.
Note that the default baud rate for the module is 115200, so the terminal program in use should be configured to use that baud rate.
Xpress Configurator is a graphical configuration tool for Bluetooth Xpress modules. With this tool, users can connect to a BGX device through a serial-to-USB bridge to adjust parameters and test performance. Input validation in the tool ensures that all variables remain within limits. All configurable variables include informative links that open relevant docs.silabs.com content within the tool. Xpress Configurator also includes a terminal window with a live display of all interactions between the connected PC and the Bluetooth Xpress module. This window shows how all configuration settings translate to simple get commands. This terminal can also be used to test communication if the Bluetooth Xpress module has established a BLE connection.
Note that some early BGX13P evaluation boards are not recognized by Simplicity Studio. To correct this problem, the CP2102N on the evaluation board needs to be reconfigured. Instructions on how to do this are here.