UART ports detection

Hardware Questions and Recommendations
1

Hello there. I tried to detect UART pinout for
TP-Link TL-WA801ND rev5
accordingly to documentation from openwrt
and one more wonderful article

This is what I measured so far:

  1. grnd for sure is detected via multimeter’s continuity.
  2. TxD seems correct as well since voltage jumps around during boot

TP_Link_TL-WA801NDv5_serial_uart_pinout
TP_Link_TL-WA801NDv5_serial_uart_pinout1920×2557 362 KB

What conclusion should I make? Is some resistor missing?

2

I flashed such a device over the serial port years ago. It was around so I opened it.

Indeed, the voltage between RX and GND is 0 V, but serial works fine.

The weird thing is that I couldn't get it to work with putty and had to use Tera Term.

Just solder a connector and go ahead.