I'm playing with the sensor/sink example on the EFR32 Flex Gecko 2400/915 MHz Starter Kit (SLWSTK6060A).
I would like to modify the sensor example to read/write data from an asynchronous serial device on the expansion header (pins 12,14, and GND) and send it to the sink.
I've noticed that the command interpreter sends its output to this UART. Oddly, it doesn't read input from this UART. Is there any easy to prevent this from happening? I still need to communicate with the command interpreter from the Simplicity IDE.
Firstly, virtual com of main board controller is connected to the mcu's usart0 of the radio board, so you can't use usart0 to be connected to other device at the same time.
If you want to let the target mcu communicate with other device through serial port, please use usart1. You need add some code for usart1, such as initialization, transmit/receive interface, etc. For this, you should check the mcu's datasheet and wstk's document/circuit to select which pins could be used for usart1.
Okay, I think I see how this works. According to the schematic, USART1 is connected to serial flash. But as long as the CS (chip select) pin of the serial flash is not asserted, I can re-program the lines as a UART.