Asus wifi router with DDwrt and serail connector

28 may 2025

Flashing the Asus RT-AC68U router with DDwrt and had a usb-serial connector to the router.

I would like to install DD-wrt (not openwrt, check at the end of this article to see why ) on an Asus wifi router to avoid using firmware from asus. This wifi router is a dual band wifi and some other features like QoS, File Sharing ???, Printer Sharing ??? some android and ios App ??? and of course "cloud" and "AI". What can possibly go wrong ?
My previous router was a very old linksys wrt54G with ddwrt as "firmware", and finally he died. It's time to use a "new" wifi router.

I have an "old" Asus RT-AC68U on my desk for a long time, this router is still supported by asus, on the support web page a recent firmware update is available Version 3.0.0.4.386_51733 2025/03/10. So it's time to open it and check what's inside. That was not really easy some hidden screws (2) behind the sticker, but with the help of this video

https://www.youtube.com/watch?v=yjQf4N6VlUY that's was really helping.

Installing ddwrt on the router was really easy, check on the database router from ddwrt :

https://dd-wrt.com/support/router-database/

They also provide the factory flash for the router if you prefer to get back to the original firmware from asus. They also provide a step by step document for flashing the ddwrt on the router,

https://wiki.dd-wrt.com/wiki/index.php/Asus_RT-AC68U#Firmware_Install_Procedure.

The last step was to install the usb to serial connector to get a "physical" acces to the router even in case of network problem. To install the usb-to-serail converter you must remove the pcb from the case. The serial connector is on the other side near the top between the wireless antenna connectors. It operates at 115200 baud 8N1. Just remember to connect the tx to rx and rx to tx on the connector, check on the photo at the end of this article.

You can also use Openwrt, but if you are using openwrt it is possible the wifi 2.4Ghz do not work properly. Check at the top of this page before flashing your router :
https://openwrt.org/toh/asus/rt-ac68u

2.4Ghz WiFi is not partly supported as was previously thought!

https://openwrt.org/

To find your router check is this page :

https://toh.openwrt.org/?view=normal

May be you don't need 2.4Ghz ? The big advantage for 2.4Ghz is its greater range and fewer problems with obstacles like walls. 5G wifi has more bandwith but its range is about half that of 2.4 Ghz wifi. In addition, obstacles can cause siginificant problems and even disconnections.

If you really want an opensource router and a openwrt firmware check on this page of openwrt project :

https://openwrt.org/

November 29, 2024 marks the release of the OpenWrt One, the first router built with your right to repair and software freedom in mind. Powered by MediaTek MT7981B SoC, it boasts features like dual-band WiFi-6, POE, dual Ethernet ports, and a mikroBUS expansion header. Priced at US$89, this hacker-friendly router is unbrickable and FCC-compliant.

Regardless of where you buy from, for every purchase of a new OpenWrt One, a US$10 donation will go to the OpenWrt earmarked fund at SFC. Your purchase not only improves your software right to repair, but also helps OpenWrt and SFC continue to improve the important software and software freedom on which we all rely!