I am looking to build a custom board using nrf52840 and want both UART and flashing capabilty on the custom board. I have a NRF52840dk that I will use to program the custom board and act as an interface for uart for the custom board. I am planing on using a USB port on the custom board. Now since the usb port has 5 pins at max where as I need 6, power, gnd, swdio, swdclk, rx & tx for uart.
What are my options here. I have the following ideas would be great to know if they are possible:
- I don't power the custom board via usb and power it using a battery and connect all other pins to the DK.
- I use RTT instead of UART for communication and data transfer that would take four pins.
- If there is a way to use the swd pins for uart.
Thanks in advance.
