TD-W8970 serial connection


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.

Now I'm getting this:

Can someone point out what I'm doing wrong?

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

Thanks for the reply.

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.

Vcc must not be connected on a USB to serial adapter, only GND, RX and TX.

1 Like

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

1 Like

A->B is conversion direction.
USB is on side A so TTL/232 need to be on side B

That said, I'm using the 232 pins not the TTL pins, should I be using the TTL pins?

I'l give that a try.

I disconnected the vcc pin and it did the same, disconnected the GND and I got nothing.

Using the TTL pins worked!

Thanks for all the help guys!


Next question (sorry if its a stupid one).

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 think It;s time for you to read up on TFTP servers


this is the one i like to use at lest for windows 7


Thanks! Ive set up the tftp server and Im busy uploading the bin file. I assume that it should work the same as the image file.

Ok hang on, Am I supposed to let the router boot and then log onto it and upload or am I suposed to interupt the boot and then upload and write?

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

Thanks again.

with this command : sf write 0x81000000 0x20000 0x$(filesize)

Do I specify the file size in bytes or hex?
sf write 0x81000000 0x20000 0x$(5046461)
sf write 0x81000000 0x20000 0x$(4d00bd)

Thanks for the help!

Edit: Nevermind, I'm overthinking it :stuck_out_tongue:

Ok awesome, I'll try again without vcc when I get back. Thanks for the help.

This topic was automatically closed 10 days after the last reply. New replies are no longer allowed.