Table of contents

RoadTest: Silicon Labs Bluetooth Design Kit

Author: gustavovelascoh

Creation date: 7 Feb 2020

Evaluation Type: Development Boards & Tools

Did you receive all parts the manufacturer stated would be included in the package?: True

What other parts do you consider comparable to this product?: Nordic platforms with their software examples (like the serial bridge), but the BGX13P is a plug-and-play solution if you don't require excessive flexibility and are more focused on the application.

What were the biggest problems encountered?: Not big functional issues, but some minor bugs on the XpressConfigurator. But the mobile app has some issues that could be annoying when trying to connect, and interact with the device.

Detailed Review:

• Introduction:
• BGX13P
  • Order a Bluetooth Xpress Starter Kit
  • Download de BGX Commander Mobile App
  • Download and Install Simplicity Studio
  • Plug-in Kit and Run Simplicity Studio
  • Run BGX Commander and Connect to the BGX13P
  • Explore Development Resources
• EFM8 Universal Bee Starter Kit
  • Using Advanced Energy Monitor
• Conclusions

Introduction:

For this Roadtest, I evaluated Silicon Labs’ Bluetooth module WirelessXpress BGX13P and the Get Started procedure on Ubuntu 18.04 and Android. Additionally, as the EFM8 Universal Bee Starter Kit was included in the Roadtest, I also did some testing on it.

These are two wonderful pieces of hardware: the BGX13P is "serial cable replacement", it is almost plug-and-play and it has certain flexibility features on GPIO that make of it the to-go option for certain applications. And although it is more expensive than other Bluetooth modules, it is small, already certified and ready to go. Once you have the hardware, your serial link is ready within minutes. The EFM8 Universal Bee is a nice kit, including an 8-bit platform (EFM8UB10F16G) and supporting a display, joystick, expansion header and more. A nice feature that I tested was the Advanced Energy Monitor through Simplicity Studio, comparing the current consumption vs the configured transmission power.

I focused on following the "Get Started" guides for the product and did additional tests.

BGX13P

Following the guide found at Silabs website (Guide here) there are 6 steps I will follow, highlighting any issue that is not considered in the documentation. The 6 steps are:

1. Order a Bluetooth Xpress Starter Kit
2. Download de BGX Commander Mobile App
3. Download and Install Simplicity Studio
4. Plug-in Kit and Run Simplicity Studio
5. Run BGX Commander and Connect to the BGX13P
6. Explore Development Resources

Now, I will describe my experience through the steps:

1. Order a Bluetooth Xpress Starter Kit

I would like to thank Element14 community and Silicon Labs for sending me the BGX13P and EFM8 Development Kit for reviewing it. And a special thank to E14’s RoadTest Program and itsManager, Randy Scazny for running this program. (So they completed this step for me)

2. Download de BGX Commander Mobile App

For this step, the Android version of BGX Commander App will be downloaded and Installed using Google Play store. The first screen asks for turning on the Bluetooth and once it is enabled, the BGX13P is detected. Tapping on the discovered device, opens a simple terminal interface with mode selector (Stream and Command modes).
A warning symbol is displayed, indicating that a newer firmware version is available. Tapping in “update” button, lists the current version, the list of versions for installing, and a link to the version release notes. The following screenshots show the steps described before.

3. Download and Install Simplicity Studio

First, you need to register to download Simplicity Studio Version 4. As stated before I’m on Ubuntu so I installed the Linux version which is around 210 MB. Here is a direct link to the compressed file https://www.silabs.com/documents/login/software/SimplicityStudio-v4.tgz
Then, I uncompress the downloaded file using the command “tar -zxvf SimplicityStudio-v4.tgz” and open the README.txt file, which contains instructions for Ubuntu 16.04. However, they should work on 18.04 (And they did!)

4. Plug-in Kit and Run Simplicity Studio

Once Simplicity Studio was installed, I proceeded to plug the BGX13P and start it. I selected the option “Install by Device” and chose the “Blue Gecko Xpress - BGX13P Evaluation Kit”. Then installed packages for supporting 8051, 32-bit platforms and also Xpress configurator. (As can be seen for the pictures, there are some issues handling the dark theme for the interface)

After that, I was able to create a project and start communicating with the kit through the Xpress Configurator interface (Additional downloads were required).

When the RoadTest started I was using Simplicity 4.0 and always appeared a message stating that the Firmware should be updated in the board, even when I had already done it. Updating to Simplicity 4.2 solved that issue.

Another issue I noticed is that if I am connected to the BGX13P through the BGX Commander App, Simplicity and the Xpress Configurator is unable to connect to the board. And sometimes is it not possible to re-connect to the board after clicking on Disconnect, I needed to re-plug the kit to reconnect.

5. Run BGX Commander and Connect to the BGX13P

Finally, some messages were exchanged between BGX Commander and the BGX13P, using XpressConfigurator.

5. Explore Development Resources

Additional resources that are useful to know more about the platforms:

• Product website: https://www.silabs.com/products/development-tools/wireless/bluetooth/bgx13p-bluetooth-xpress-starter-kit
• Commands and variables documentation: https://docs.silabs.com/gecko-os/1/bgx/latest/
• Github repo for Wireless Xpress codebase and tools: https://github.com/SiliconLabs/wireless-xpress

EFM8 Universal Bee Starter Kit

Using Advanced Energy Monitor

In this test, Advanced Energy Monitor is used to measure the changes in current consumption depending on the configuration of the transmission power. The kit was connected to Simplicity Studio, the EFM8UB1 BGX demo was loaded and once it was running as peripheral, BGX Commander application was connected to the BGX13P, and using the command mode, the transmission power was configured using the command ```set bl c t XX``` where XX is the desired power, a number between 8 and -25.

AEM allows to record the session and export it as a csv file. For the test, I set up the board and the phone around 50cm apart and changed the transmission power to 8, 5, 3, -1, -4, -7, -10, -13, -16, -19, -22, -25. I also recorded the RSSI value shown in BGX Commander App. The first plot shows the current consumption and Tx Power vs time. This current includes both the EFM8 and BGX13P consumption. When it is connected transmitting at 8dB, the current is on average 7.8mA, however, the lowest current on average is ~6.7mA when the transmission power is below than -1dB. There is no big change in lower transmission power values. The second one shows the relation between the Tx Power and the RSSI reported by the mobile App.

Conclusions

• The BGX13P is the to-go platform if what you want is to replace a serial cable with a Bluetooth bridge without spending a lot of time in development.
• BGX Commander App still needs to provide more stability to make the exploration and evaluation stage more enjoyable and less annoying. Some additional features and in-app documentation would be nice
• Simplicity Studio provides a nice development environment and especially AEM tool is very handy when you have to focus on energy consumption.