I'm trying to connect to my TD-W8970 V1 via serial. I followed this page and soldered the headers onto the board. I did not get any feed back until I swapped the rx/tx cables.
well you have something it's a start
3 thing's id check
baud rate & stop bits ect
polarity make sure gnd is on gnd & tx is connected to rx ect
voltage of serial adapter & router
make sure they match router is most likely router is 3.3V
will serial adapter accept logic levels of 3.3V
I checked the baud and stop bits as per the page I linked, I used GND3 for ground as per the page and I'm using this serial board. Ive connected the VCC to the 3.3v pin, tho I left the ground on the one near the serial connector.
I can't see from the page you sent if the logic for the rx & tx pin are +3.3v
or +5V
as slh has already stated most adapters you don't want to connect anything else but gnd tx & rx
there is an inverter in most adapters I'm not sure what how this one presents it's signals
from what I can see of your adapter you want to use the A=TTL pins GND,TX & RX
Step 6 Download the image into RAM (not flash):
tftpboot 0x81000000 openwrt-lantiq-xrx200-TDW8970-sysupgrade.image
This step had me stumped, how do I tell the device where the file is located, (or where should the file be located) and I downloaded a bin file not an image file.
I have done this on a W8980 but it's been a while
these devices are almost the same having a quick look they have the .bin extension
but have a look for yourself