Right i have 2 CP210x USB to UART PCB's which i plan to make a permanent fixture to both my Linksys WRT32x and GLiNet Flint AX1800, it should be safe to just leave it in the router(s) right so its just then a simple case of using a Micro USB cable to get Serial TTL output right?
Not planning on connecting the VCC pins for 5v or 3.3v (don't want to fry router or USB TTL). Only GND and TX,RX pins will be connected permanently.
Only asking so i know how to plan the case mods. I know it might not seem like its to do with OpenWRT however its so i can test OpenWRT build and get console output or be able to TFTP incase of bricks etc.
Normally yes, but test it first - some combinations won't power-up correctly if the usb2serial adapter is already connected before applying power (because power from the USB side is backfeeding into the SOC through the tx line and leaves the SOC in a confused state).