bluetooth_explorer_kit_i2c_barometer

Bluetooth - Barometer I2C

Overview

This project shows an example of Bluetooth - Barometer I2C using the Silicon Labs BGM220-EK4314A BGM220 Bluetooth Module Explorer Kit.

This example is intended to make a pressure and temperature measurement every second when the Bluetooth connection is open. The measurement can be seen via Bluetooth Pressure and Temperature characteristics under the Environmental Sensing service by reading it manually, or it can also be automatically updated using notifications.

The application uses a Mikore Pressure 3 Click using mikroE mikroBUS-socket I2C connection. Moreover, SparkFun Micro OLED Breakout is used to display the measurement value on the screen.

This example can be used as a barometer pressure sensor in the weather station or an altitude sensor and so on.

Gecko SDK version

• GSDK v4.4.0
• Third Party Hardware Drivers v2.0.0.0

Hardware Required

• BGM220-EK4314A BGM220 Bluetooth Module Explorer Kit (BRD4314A BGM220 Explorer Kit Board)

• MikroE Pressure 3 Click based on DPS310 sensor.

NOTE: Tested boards for working with this example:

Board ID	Description
BRD4314A	BGM220 Bluetooth Module Explorer Kit - BGM220-EK4314A
BRD2703A	EFR32xG24 Explorer Kit - XG24-EK2703A
BRD4108A	BG22 Bluetooth SoC Explorer Kit - BG22-EK4108A

Connections Required

The Pressure 3 Click board can just be "clicked" into its place. Be sure that the board's 45-degree corner matches the Explorer Kit's 45-degree white line.

The following picture shows the system view of how it works.

Setup

To test this application, you can either create a project based on an example project or start with a "Bluetooth - SoC Empty" project based on your hardware.

Create a project based on an example project

1. From the Launcher Home, add your hardware to My Products, click on it, and click on the EXAMPLE PROJECTS & DEMOS tab. Find the example project with the filter "barometer".

2. Click Create button on the Bluetooth - Barometer I2C example. Example project creation dialog pops up -> click Create and Finish and Project should be generated.

3. Build and flash this example to the board.

Start with a "Bluetooth - SoC Empty" project

1. Create a Bluetooth - SoC Empty project for your hardware using Simplicity Studio 5.

2. Copy all attached files in the inc and src folders into the project root folder (overwriting existing).

3. Import the GATT configuration:

   • Open the .slcp file in the project.

   • Select the CONFIGURATION TOOLS tab and open the Bluetooth GATT Configurator.

   • Find the Import button and import the configuration bluetooth_rfid_notify/config/btconfig/gatt_configuration.btconf file.

   • Save the GATT configuration (ctrl-s).

4. Open the .slcp file. Select the SOFTWARE COMPONENTS tab and install the software components:

   • [Services] → [IO Stream] → [IO Stream: USART] → default instance name: vcom

   • [Application] → [Utility] → [Log]

   • [Third Party Hardware Drivers] → [Sensors] → [DPS310- Pressure 3 Click (Mikroe) - I2C]

5. Install printf float

   • Open Properties of the Project.

   • Select C/C++ Build → Settings → Tool Settings → GNU ARM C Linker → General. Check Printf float.

6. Build and flash the project to your device.

Note:

• Make sure that the Third Party Hardware Drivers Extension already be installed and this repository is added to Preferences > Simplicity Studio > External Repos.

• Do not forget to flash a bootloader to your board, see Bootloader for more information.

How It Works

GATT Database

The application is based on the Bluetooth - SoC Empty example. Since the example already has the Bluetooth GATT server, advertising, and connection mechanisms, only minor changes are required.

Advertisement Packet Device name: Silabs Barometer I2C

GATT Database

• Device name: Silabs Barometer I2C
• [Service] Environmental Sensing
  • [Char] Pressure
    • [R] Read pressure value.
    • [N] Notify to update pressure value automatically.
  • [Char] Temperature
    • [R] Read temperature value.
    • [N] Notify to update temperature value automatically.

Testing

After the barometer sensor initialization is successful. Bluetooth advertising will be started. When the connection is opened, the application gets the temperature and pressure from the sensor every second. If the connection is closed, also the barometer measurement timer is stopped.

You can use a smartphone app, such as the EFR Connect application on your phone, to connect to the board. Please, follow some steps below:

• Open the EFR Connect app.

• Open the Bluetooth Browser.

• Find the device advertising as Silabs Barometer I2C.

• Click on Connect button.

When the device is connected, you can read the temperature and pressure values manually. If you want these values updated automatically, you have to enable the Notify property for them, so the client device is notified about the value updated.

You can launch Console that's integrated into Simplicity Studio or use a third-party terminal tool like TeraTerm to receive the data from the USB. A screenshot of the console output is shown in the figure below.