UART testing
If you wish to test the different UARTs you can do this by using NXPs commandline UART-read-write tool. Every UART has it's own FriendlyName which has been specified in the ACPI, more about this here. This tool allows you to list these FriendlyNames and configure the ports for the session after pasting the necessary prompt with the specified FriendlyName.
How to use the tool
1) Download the UART-read-write tool
Open the UART-read-write.vcxproj solution after downloading the tool. Head to Build > Configuration Manager and change the Active solution platform to ARM64. Build the solution.
2) Copy the binary file
The binary file can be found by opening the Solution Explorer > right-click the solution > Open Folder in File Explorer > ARM64 > Debug.
Establish a remote connection to the board, copy and paste the UART-read-write.exe into a folder of your choice.
3) Use the tool
Open cmd and navigate to the directory containing the tool. Paste in the following command to list your serial ports. The PortName is the FriendlyName which can be used to communicate with the serial port.
Copy and paste the following command and replace UART_A with the PortName of the serial port in your list.
After this you will be prompted to select a baudrate which can be seen in the following figure. Press enter, this will select a baudrate of 115200.
You should see the configuration and a prompt asking you to send a message. Entering a 1 means sending 1 byte. Reference your boards documentation to figure out where the UART pins are located. For this test to succeed you have to connect your board to a machine you wish to communicate with. Another choice would be to short the Rx and Tx pins of the boards UART.
Hit CTRL+C to exit the session.
Accessing the serial ports in your own UWP application
If your application needs to interact with the serial port you can use the symbolic link listed above the PortName,
e.g. \\?\ACPI#NXP0113#1#{86e0d1e0-8089-11d0-9ce4-08003e301f73}\SERCX. A guide to access the serial port in your own UWP application can be found here
