nRF52840 uart not available

[Oetze]

We are working with Zephyr to program the development kit for now and later the real board,

We need access to both UART0 and UART1 but we can't seem to get UART1 to work

According to the Virtual serial port (nordicsemi.com) the "other" uart isn't available. 

We were wondering why it wasn't available and how we might enable it anyway. Is it not physically connected? 

We tried setting the RX/TX lines to P1.01 and P1.02 (arduino_serial according to the board dts file)

We've tested it with the samples/driver/uart code in the zephyr libraries, it worked for uart0 but not uart1.


How can we enable uart1? 

[Hieu]

Hi Oetze,

We were wondering why it wasn't available and how we might enable it anyway. Is it not physically connected? 

Yes, there is only 4 pins between the DK's Interface MCU and the nRF52840. You can see the details in the DK schematic.
The Interface MCU firmware uses this interface to emulate its VCOM0 port.

We tried setting the RX/TX lines to P1.01 and P1.02 (arduino_serial according to the board dts file)

We've tested it with the samples/driver/uart code in the zephyr libraries, it worked for uart0 but not uart1.


How can we enable uart1? 

Seems like you have figured out how to overlay the Devicetree and change pin assignment. UART1 should be enabled by default on the DK Devicetree.

Could you please share more details of what you have done with the Devicetree, and your compiled <build dir>/zephyr/zephyr.dts file?

Hieu