TP-Link Archer C20 v4 Build

I'm also wondering whether the 2.4GHz wifi works reliably, because it has same radio as wr841n v13 (MT7628N). Also TL-MR3420 V5 has the same radio.

1 Like

Hey could you explain how you got 5Ghz working?

As I said, a fair bit of hacking.

  1. I manually copied the mediatek project [1] into the “packages” directory
  2. and built the binary (after enabling it with “make menuconfig”).Manually added the initial network configuration, as per the rai0.sh script in the mediatek package
  3. Manually ran the mediatek configuration conversion, as per the rai0.sh script.

I can't provide any more details than that.

2 Likes

Friend, can you replicate the solution here? The openwrt forum is dead.

1 Like

Just wanted to feedback two things about this router:

1 - Have flashed 18.06.1 and also Snapshot versions and the 2.4 Ghz wifi does not work reliably. It comes up in the first couple of minutes after de router came up. Then after some devices connect the wifi it starts to disappear and doesn't come back until the next reboot.

What driver MT7628AN is using ? Did it come from the vendor or is some open sourced one ?

2 - After flashing it with OpenWrt 18.06.1 I tried to do the sysupgrade image from @Linaro but somehow it doesn't work, even using either the "sysupgrade -v" command instead of the tftp method.
What is more strange is that after trying to sysupgrade this version the router reboots into the original TP-Link firmware and web interfaceand with the previous saved configuration. I didn't understand this router had any kind dual-boot system or even enough flash memory for it.

Has anyone got any better or different results ?

Hello folks

I wanted to mentioned that I just saw a pull request (https://github.com/openwrt/openwrt/pull/1496) sent a few days ago to add 5 Ghz support to another router (D-Link D-810L) which uses the same Wireless 5Ghz chip as this C20 v4 (MT7610E).

The author says the support for C20v4 is already in place at (https://github.com/openwrt/openwrt/blob/900005ee75754ba62972ed8da6eba2d6b47e1b7f/target/linux/ramips/dts/ArcherC20v4.dts#L97-L105).
And that it requires the "kmod-mt76x0e" be added to the image build (https://github.com/openwrt/openwrt/blob/master/target/linux/ramips/image/mt76x8.mk) and the line "DEVICE_PACKAGES := kmod-mt76x0e" to the C20v4's target.

Is anyone able to confirm it ?

1 Like

please tell me what is the IP address for web interface after flashed?

@ffredy Have you tried a recent snapshot image? https://openwrt.org/toh/hwdata/tp-link/tp-link_tl-mr3020_v3

I just tried this after reading your post, since I too would be happy with just 5 Ghz client mode to use my phone's 4G if my WAN goes down. Short story, the driver is available via opkg, installing it now shows the new radio but it doesn't work, in any mode.

root@Archer-C20v4:~# dmesg | grep mt76x0e
[   11.653963] mt76x0e 0000:01:00.0: card - bus=0x1, slot = 0x0 irq=4
[   11.660505] mt76x0e 0000:01:00.0: ASIC revision: 76100002
[   12.007076] mt76x0e 0000:01:00.0: Firmware Version: 0.1.00
[   12.410036] mt76x0e 0000:01:00.0: EEPROM ver:02 fae:00

root@Archer-C20v4:~# iw list
Wiphy phy1
	max # scan SSIDs: 4
	max scan IEs length: 2247 bytes
	max # sched scan SSIDs: 0
	max # match sets: 0
	max # scan plans: 1
	max scan plan interval: -1
	max scan plan iterations: 0
	Retry short limit: 7
	Retry long limit: 4
	Coverage class: 1 (up to 450m)
	Available Antennas: TX 0x1 RX 0x1
	Supported interface modes:
		 * IBSS
		 * managed
		 * AP
		 * AP/VLAN
		 * monitor
		 * mesh point
	Band 2:
		Capabilities: 0x17e
			HT20/HT40
			SM Power Save disabled
			RX Greenfield
			RX HT20 SGI
			RX HT40 SGI
			RX STBC 1-stream
			Max AMSDU length: 3839 bytes
			No DSSS/CCK HT40
		Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
		Minimum RX AMPDU time spacing: 4 usec (0x05)
		HT TX/RX MCS rate indexes supported: 0-7
		VHT Capabilities (0x01800120):
			Max MPDU length: 3895
			Supported Channel Width: neither 160 nor 80+80
			short GI (80 MHz)
		VHT RX MCS set:
			1 streams: MCS 0-7
			2 streams: not supported
			3 streams: not supported
			4 streams: not supported
			5 streams: not supported
			6 streams: not supported
			7 streams: not supported
			8 streams: not supported
		VHT RX highest supported: 0 Mbps
		VHT TX MCS set:
			1 streams: MCS 0-7
			2 streams: not supported
			3 streams: not supported
			4 streams: not supported
			5 streams: not supported
			6 streams: not supported
			7 streams: not supported
			8 streams: not supported
		VHT TX highest supported: 0 Mbps
		Frequencies:
			* 5180 MHz [36] (20.0 dBm)
			* 5200 MHz [40] (20.0 dBm)
			* 5220 MHz [44] (20.0 dBm)
			* 5240 MHz [48] (20.0 dBm)
			* 5260 MHz [52] (20.0 dBm) (radar detection)
			* 5280 MHz [56] (20.0 dBm) (radar detection)
			* 5300 MHz [60] (20.0 dBm) (radar detection)
			* 5320 MHz [64] (20.0 dBm) (radar detection)
			* 5500 MHz [100] (23.0 dBm) (radar detection)
			* 5520 MHz [104] (23.0 dBm) (radar detection)
			* 5540 MHz [108] (23.0 dBm) (radar detection)
			* 5560 MHz [112] (23.0 dBm) (radar detection)
			* 5580 MHz [116] (23.0 dBm) (radar detection)
			* 5600 MHz [120] (23.0 dBm) (radar detection)
			* 5620 MHz [124] (23.0 dBm) (radar detection)
			* 5640 MHz [128] (23.0 dBm) (radar detection)
			* 5660 MHz [132] (23.0 dBm) (radar detection)
			* 5680 MHz [136] (23.0 dBm) (radar detection)
			* 5700 MHz [140] (23.0 dBm) (radar detection)
			* 5745 MHz [149] (disabled)
			* 5765 MHz [153] (disabled)
			* 5785 MHz [157] (disabled)
			* 5805 MHz [161] (disabled)
			* 5825 MHz [165] (disabled)
	valid interface combinations:
		 * #{ IBSS } <= 1, #{ managed, AP, mesh point } <= 8,
		   total <= 8, #channels <= 1, STA/AP BI must match, radar detect widths: { 20 MHz (no HT), 20 MHz, 40 MHz, 80 MHz }

	HT Capability overrides:
		 * MCS: ff ff ff ff ff ff ff ff ff ff
		 * maximum A-MSDU length
		 * supported channel width
		 * short GI for 40 MHz
		 * max A-MPDU length exponent
		 * min MPDU start spacing
	Device supports VHT-IBSS.
Wiphy phy0
	max # scan SSIDs: 4
	max scan IEs length: 2257 bytes
	max # sched scan SSIDs: 0
	max # match sets: 0
	max # scan plans: 1
	max scan plan interval: -1
	max scan plan iterations: 0
	Retry short limit: 7
	Retry long limit: 4
	Coverage class: 1 (up to 450m)
	Available Antennas: TX 0x3 RX 0x3
	Supported interface modes:
		 * IBSS
		 * managed
		 * AP
		 * AP/VLAN
		 * monitor
		 * mesh point
	Band 1:
		Capabilities: 0x1fe
			HT20/HT40
			SM Power Save disabled
			RX Greenfield
			RX HT20 SGI
			RX HT40 SGI
			TX STBC
			RX STBC 1-stream
			Max AMSDU length: 3839 bytes
			No DSSS/CCK HT40
		Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
		Minimum RX AMPDU time spacing: 4 usec (0x05)
		HT TX/RX MCS rate indexes supported: 0-15
		Frequencies:
			* 2412 MHz [1] (20.0 dBm)
			* 2417 MHz [2] (20.0 dBm)
			* 2422 MHz [3] (20.0 dBm)
			* 2427 MHz [4] (20.0 dBm)
			* 2432 MHz [5] (20.0 dBm)
			* 2437 MHz [6] (20.0 dBm)
			* 2442 MHz [7] (20.0 dBm)
			* 2447 MHz [8] (20.0 dBm)
			* 2452 MHz [9] (20.0 dBm)
			* 2457 MHz [10] (20.0 dBm)
			* 2462 MHz [11] (20.0 dBm)
			* 2467 MHz [12] (20.0 dBm)
			* 2472 MHz [13] (20.0 dBm)
			* 2484 MHz [14] (20.0 dBm)
	valid interface combinations:
		 * #{ IBSS } <= 1, #{ managed, AP, mesh point } <= 4,
		   total <= 4, #channels <= 1, STA/AP BI must match
	HT Capability overrides:
		 * MCS: ff ff ff ff ff ff ff ff ff ff
		 * maximum A-MSDU length
		 * supported channel width
		 * short GI for 40 MHz
		 * max A-MPDU length exponent
		 * min MPDU start spacing
root@Archer-C20v4:~#

The only log entry about the 5 Ghz radio is in dmesg IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready. If anyone has ideas on getting this to work, I'm all ears.

@ffredy thank you! I've included the line "DEVICE_PACKAGES := kmod-mt76x0e" in the ./target/linux/ramips/image/mt76x8.mk C20v4's section and recompiled the last snapshot tree, with the C20v4 ramips target, default options, plus Luci. After the upload to the router (using tftp method), I configured the 5GHz WiFi interface using Luci and worked! The only thing I noticed is the low RF power. I can only use the 5 GHz Wifi in the same room. 2.4 GHz is ok.

Hello @marciolm
Thanks for the feedback.

With regards the 5Ghz power that actually doesn't look strange as 5Ghz in some buildings can be easily blocked by walls. 2.4Ghz always goes much father.
There are some routers that have a bit more power for 5 Ghz radios but that's normally a hardware feature not a driver (which can control it).

It would be good to test with the original firmware and find out if it makes any difference on the distance over 5Ghz in the same position, then if it's the case report to the developer at https://github.com/openwrt/mt76

Thank you! I will send a message to the developer. The measured power (about -60 dBm in 1m from the antenna) is much lower than obtained with the original firmware and the WiFi led does not light. But, anyway, the 5GHz support to this device is a good news, after so long time!

This is what I got:

 -----------------------------------------------------
 OpenWrt SNAPSHOT, r8629-f98fde2db4
 -----------------------------------------------------
root@OpenWrt:~# cd /etc/config/
root@OpenWrt:/etc/config# cat wireless

config wifi-device 'radio0'
        option type 'mac80211'
        option hwmode '11g'
        option path 'platform/10300000.wmac'
        option legacy_rates '1'
        option channel '1'
        option htmode 'HT40'
        option country 'US'
        option txpower '30'

config wifi-iface 'default_radio0'
        option device 'radio0'
        option network 'lan'
        option mode 'ap'
        option ssid 'OpenWrt'
        option encryption 'psk2'
        option key 'xxxxxxxx'

config wifi-device 'radio1'
        option type 'mac80211'
        option hwmode '11a'
        option path 'pci0000:00/0000:00:00.0/0000:01:00.0'
        option htmode 'VHT80'
        option country 'US'
        option legacy_rates '1'
        option channel '112'

config wifi-iface 'default_radio1'
        option device 'radio1'
        option network 'lan'
        option mode 'ap'
        option ssid 'OpenWrt5G'
        option encryption 'psk2'
        option key 'xxxxxxxxxx'

root@OpenWrt:/etc/config# iwinfo wlan1 info
wlan1     ESSID: "OpenWrt5G"
          Access Point: 00:0C:43:26:60:xx
          Mode: Master  Channel: 112 (5.560 GHz)
          Tx-Power: 23 dBm  Link Quality: unknown/70
          Signal: unknown  Noise: unknown
          Bit Rate: unknown
          Encryption: WPA2 PSK (CCMP)
          Type: nl80211  HW Mode(s): 802.11nac
          Hardware: 14C3:7650 14C3:76xx [Generic MAC80211]
          TX power offset: unknown
          Frequency offset: unknown
          Supports VAPs: yes  PHY name: phy1

1 Like

Hello Gents,
I am a newbie, probably this will be obvious... I am experinecing the same unreliabilty on 2.4GHz wifi as mentioned earlier (after installing package 18.06.01). Is there any simple way to get rid of this? Should I install some extra packages or replace existing ones?
Your support is appreciated,

So 5.8Ghz work for now? if so, please share how to install them..

Hello @marciolm
I am new to this forum and not a developer
I have a requirement of 5ghz in my archer c20v4
with the official openwrt build i am able to use only 2.4 ghz
so can u please post any bin to directly flash in my router to access 5ghz in AP mode or else give the clear procedure to make use of 5ghz radio.

thank you

you need to be a developer :stuck_out_tongue:

Thanks for ur reply:grimacing:

using WinSCP right? *for windows

Hello,
Tried to make tp_recovery for tftp from the last firmware with bs=512 skip=1. "Archer_C20v4_BR_0.9.1_4.16_up_boot[190103-rel70848].bin", but after tftp download on router, bootloop.
Any ideia?

dunno, i got everything work perfectly

@any1 tell me how i get 5ghz wifi in AP Mode ? I see only 1 wifi

Support for Archer C20 v4 has been added quite a while ago, and since official release builds are available, this topic will be closed now.

Please open new topics for any remaining questions.