Using J-Link with external UART

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Using J-Link with external UART

I am attempting to use UART2 to send serial information to an external device and have connected up the J4 header on the DA14580 Basic Development Board to do that. This is based on the use of UART2 as outlined in section 13 of UM-B-3. When I connect the UART2 pins to the TX and RX pins to drive the serial interface through the USB port I can get console output on the PC hosting the Keil uVision software. When I move these pins to drive the serial port of the external device I can no longer communicate with the DA14580 (get pop up error message on attempting to run the debugger that no cortex M0 device has been found).

I assume this means that the serial interface is being used by the J-Link to load the code into the DA14580 (or some other management function). Is this correct?

If that is the case, how can you use UART1 to support the J-Link interface and UART2 to drive the external serial device?

I attempted defining the different port maps, and added uart.c to the drivers group (that already had uart2.c). This ended up generating multiply defined symbols.

Given that you need to use both uarts to support use of the J-Link debugger and external serial device,

Is there an outline of how to go about configuring the DA14580 to allow both UARTs be running together? Also would like to know why uart.c is different from uart2.c.

gl_dialog (not verified)
Dear Barry,

Dear Barry,


JLINK is using the pins P14 (SW_CLK) & P15 (SWDIO) to load the code into the DA14580.

==> Are you using these pins for UART? If so, it can work indeed.