Serial peripheral uart example not working

[amarin]

Hi,

I am currently running the example found in \examples\peripheral\serial_uartes directory using the SDK 15.3.0. I am currently trying to connect 2 nrf52840 DK UART connections together to communicate with each other. I initially ran them independently using the example found in \examples\peripheral\serial. Both devices were able to run the code, however, when I connected one device to the other via their respective UART connections, nothing happens. I have not changed anything in the code. I have tried connecting them in different ways and but it does not seem to change the same outcome.

Any advice as to what else I should be checking would be greatly appreciated!

[Jørgen Holmefjord]

Hi,

The serial_uartes example is intended for showing how to use both UARTE instances in the nRF52840 chip, this is not required to communicate between two chips. The connections required for the example to work as expected is described in the example documentation.

Was it not working with the single instance serial examples?

Can you show/describe exactly how you connected the devices?

Best regards,
Jørgen

[amarin]

It was working with the single instance when I was connecting the device's respective UART ports as so: RX > TX, RTS > CTS. However, when I was trying to connected the two devices together via their UART ports as so: RX1 > TX2, RX2 > TX1, RTS1 > CTS2 and RTS2 > CTS1 , it would not display the keys I pressed on my PC to the terminal. 

Color	Connection
Red	RTS1 > CTS2
Green	TX1 > RX2
Red	CTS1 > RTS2
Yellow	RX1 > TX2

[Jørgen Holmefjord]

If you are using the example with two UARTEs (serial_uartes), then you also need to connect P0.26 to P0.27 on each DK. As described in the documentation, the UARTE0 RX input (P0.08) is output on TX (P0.27), and input is expected on UARTE1 RX (P0.26), which again will output the data to UATE1 TX output (P0.06).

The point of this example is just to show how you can use the library with two separate UARTE instances, it does not make sense to use it like this in any practical application.