I've managed to get the TL-MR3420 V3 running on CC and trunk by patching and compiling it using

define Device/tl-mr3420-v3
    $(Device/tplink-4mlzma)
    BOARDNAME := TL-WR841N-v9
    DEVICE_PROFILE := TL-MR3420
    TPLINK_HWID := 0x34200003
endef

The boards are similar with
Edited to correct SOC model
SOC QCA9531-BL3A
RAM Zentel A3S56D40GTP-50L

But the gpio's are screwed up and only the WPS led coming on at boot at staying solid. If I plug a cable in port 4 most of the led's start flashing but other than that I can't get any activity on the led's.

Output on the V3 then the V2
3420 V3
cat /sys/kernel/debug/gpio
GPIOs 0-17, ath79:
gpio-0   (sysfs               ) in  hi
gpio-3   (tp-link:green:qss   ) out lo
gpio-4   (tp-link:green:wan   ) out hi
gpio-11  (tp-link:green:lan4  ) out hi
gpio-12  (Reset button        ) in  hi
gpio-13  (tp-link:green:wlan  ) out hi
gpio-14  (tp-link:green:lan3  ) out hi
gpio-15  (tp-link:green:lan2  ) out hi
gpio-16  (tp-link:green:lan1  ) out hi
gpio-17  (WIFI button         ) in  hi

3420 V2
cat /sys/kernel/debug/gpio
GPIOs 0-22, ath79:
gpio-4   (USB power           ) out hi
gpio-11  (tp-link:green:3g    ) out hi
gpio-12  (tp-link:green:lan4  ) out hi
gpio-13  (tp-link:green:wlan  ) out lo
gpio-14  (tp-link:green:system) out lo
gpio-15  (tp-link:green:qss   ) out hi
gpio-16  (WPS                 ) in  hi
gpio-17  (Reset button        ) in  hi
gpio-18  (tp-link:green:wan   ) out lo
gpio-19  (tp-link:green:lan1  ) out hi
gpio-20  (tp-link:green:lan2  ) out hi
gpio-21  (tp-link:green:lan3  ) out hi

It looks like I'll need a patch for the boardname to fix this but I'm lost where to start so any help appreciated.

(Last edited by webtron on 2 Jul 2016, 08:48)

If there is USB on the board then that's not true. There must be QCA9531.

Yes sorry you're correct it is a QCA9531-BL3A

Did you get it figured and would you be able to share your V3 compiled version?

No I pretty well hit a wall with it and got sidetracked with other work.

did you have try to build a openwrt firmware for TL-MR3420 v3 from TL-WR841N openwrt v10, is the same SoC??

They have similar hardware but I never went any further than what is posted here.

I just bough a TL-MR3420 V3 and was disappointed to notice that OpenWRT doesn't support it yet. I also do not have the skills required to patch and compile OpenWRT so I'm pretty much stuck with the original firmware. Any help with the matter would be appreciated and it doesn't matter to me if the leds work or not as long as it otherwise fully functional OpenWRT. If it helps here is a picture of the board: h tt p://imgur.com/a/5HTXh (sorry about the non-functional url. It seems that I can't post links since this is my first forum post).

dev ..please help

try wr810 image (same SOC) https://wiki.openwrt.org/toh/tp-link/tl-wr810n

(Last edited by phantnang on 5 Nov 2016, 14:51)

TL-WR810N image size is 8MB and TL-MR3420 v3 stock firmwares are only 4MB big so I'm not sure if the WR810N image will fit to flash. V1 and v2 have 4MB of flash so v3 might it have too. Can anyone confirm the v3 flash size? Webtron?

Could you please share your compiled image.

I don't have it anymore. You might be better contacting the poster over at LEDE http://lists.infradead.org/pipermail/le … 03782.html