Lab 3 - How to Integrate the RNBD Module to MPLAB® X IDE to Establish Bluetooth® Communication

Follow the steps in Lab 1 and ensure you have cloned all the necessary libraries to create this thermostat MPLAB Harmony application.

In this training module, you will learn how to transmit the temperature value read from the Temp&Hum13 Click board^TM by following Lab 2.

The next step is to add RNBD to the project graph. To do this, from the Device Resources pane, expand Wireless > BLE and add RNBD to the Project Graph.

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The RNBD Add-on Board is connected to the mikroBUS connector and communicates via Universal Asynchronous Receiver Transmitter (UART). For this thermostat application, the RNBD board is connected along with the Temp&Hum13 click on the mikroBUS using Mikroe Shuttle click. Refer to the hardware setup for more details.

From the "SAM9X75-Curiosity User Guide", note that the mikroBUS UART is interfaced to the SAM9X75 Curiosity board via FLEXCOM1_RXD and FLEXCOM7_TXD as shown in the accompanying image:

Now add the dependency to RNBD UART as FLEXCOM1. Right-click on RNBD UART, and select Available Satisfiers > FLEXCOM1 to add FLEXCOM1 to the Project Graph.

Verify the Configuration Options. For FLEXCOM1, the Baud Rate should be 115,200.

From the configuration option for RNBD, ensure Select Module Type is set to RNBD as shown in the accompanying image.

Add the pin configurations. To do this, go to Project Graph > Plugins > Pin Configuration.

For SAM9X75 Curiosity Wireless Kit, the RNBD board is connected to FLEXCOM1 via UART pins PA28 and PA29. Configure PA28 as BLE_TX and PA29 as BLE_RX as shown in the accompanying image:

Save and then click the Generate button. This will generate code for all the device resources for RNBD that have been added in the project graph.

Up to this point you used MPLAB Code Configurator (MCC) to configure and generate code to initialize the device (SAMA9X75). All that is left is for you to do is to write the application code in the main.c and app.c file.

Documentation for each of the peripheral libraries or driver libraries can be accessed as follows:

• FLEXCOM peripheral library APIs description and usage, see "2.47 Flexible Serial Communication Controller (FLEXCOM)"
• BSP library APIs can be found in bsp.h
• Debug peripheral library APIs description and usage, see "2.27 Debug Unit (DBGU)"
• RNBD library APIs can be found in rnbd.h

In this example, the temperature and humidity value read from the Temp&Hum 13 Click will be updated on the MBD mobile application when the user requests.

The example application source file for the RNBD Add-on Board used in the thermostat application.

APIs used for this application are as follows:

• RNBD_EnterCmdMode();
• RNBD_SetName(DevName,strlen(DevName)); // Device Name set to SAM9X75 Thermostat
• RNBD_RebootCmd();
• RNBD_EnterDataMode();
• RNBD_SetAsyncMessageHandler(..);
• RNBD_Read()
• RNBD_DataReady()

The source file can be downloaded and added to the project as shown in the accompanying image:

Similarly, the header file can be added as shown in the accompanying image:

The app_rnbd_task should be called periodically to receive/transmit messages from the MBD mobile application. (Refer to the sample app.c file.)

Now build the code.

While building, if you are getting error messages as shown in the accompanying image...

Add rnbd.h to the MPLAB X IDE project as shown in the accompanying image:

Refer to the sample application files.​​​​

The SAM9X75 Curiosity RNBD device name is set as SAM9X75THERMOSTAT.

 Refer to the sample application project.​​​​

To debug this application, follow the steps 1-13 in Lab 7.

The debug log will be as shown in the accompanying image:

Now to connect to SAM9X75 Curiosity via Bluetooth use the Microchip Bluetooth Data (MBD) mobile application.

On your Apple^® device, locate the App Store^® icon and download Microchip Bluetooth Data (MBD).

Install the MBD application on your mobile phone and launch the MBD mobile application.

The SAM9X75 Curiosity board device name is set to SAM9X75THERMOSTAT.

Now scan, connect, and establish communication with the SAM9X75THERMOSTAT from the mobile application.

When you are sending the message as status from your mobile application, the temperature and humidity value read from the Temp&Hum13 Click will be received in your mobile application as shown:

To boot the application from microSD™ card follow the these steps:

Observe the output as mentioned in the previous step.