Silicon labs stater kits feature a Virtual COM port interface (VCOM) that allows you to easily set up a serial connection between your PC and the kit. You can use VCOM for example to print out debug messages from your application. Typically VCOM is used over USB so it can be considered as an on-board USB-to-serial converter built-in to the starter kit. VCOM can also be used over Ethernet.
This article shows how to access the VCOM from Simplicity Studio and how to check and configure the COM port settings such as baud rate or flow control signaling.
Note: From Bluetooth SDK 2.11 onward the soc-empty example supports printf over VCOM out of the box. For further information please refer to the following KBA:
Following picture shows how to launch a console connection to your kit in Studio:
To see the debug prints from your application (running on the radio board), select the Serial 1 tab in the console:
In the example shown above, the target device is a BGM111 module running the SPP example application.
Instead of using VCOM via Studio, you can also use any other terminal program such as TeraTerm or PuTTY.
For generic information on how to add UART functionality to your Bluetooth app, see following knowledgebase article: How can I extend the Bluetooth examples with UART functionality?
When the console is lauched, you can select the Admin tab to check and modify (if needed) the virtual COM port settings:
The settings are stored permanently on the kit and they are preserved even if you power-cycle the kit.
By hitting ENTER on the Admin console you should see the WSTK> prompt. This is printed by Board Controller which is part of the firmware that runs on the starter kit main board. (Not to be confused with the application that runs on the radio board you have plugged into the starter kit).
Current settings can be checked by entering command:
The default settings are: baud rate 115200, flow control = "auto".
To see instructions how to configure the settings, enter command:
serial vcom config
For example, you can set the handshake to rtscts with command:
serial vcom config handshake rtscts
Another example: setting VCOM baud rate to 9600:
serial vcom config speed 9600
It depends on which SDK you are using. If your soc-empty project has app.c and app.h files then you need to set
#define DEBUG_LEVEL 1 in app.h for serial print to be enabled.
On an SLSTK3701A EFM32GG11 Starter Kit I get:
STK> ERROR: Command not found: "serial"