76

Re: TP-Link TL-MR3420 V2 (2.1)

this is the post you need to look at.

77 (edited by poisonz 2013-04-08 20:00:26)

Re: TP-Link TL-MR3420 V2 (2.1)

Sila wrote:
poisonz wrote:

Fortunately, there is already a working (user-compiled, non-official) OpenWRT image (Attitude Adjustment RC1) for MR3420 v2 over the internet @ openwrt-id.org.

Thank you for the fast response!

Unfortunately I can't find the mentioned OpenWRT image on the page you linked?
There seems to be only a copy from this forum where the steps are mentioned to compile it yourself for hardware revision 2 (not 2.1):
https://forum.openwrt.org/viewtopic.php?pid=188467#p188467

Sorry, I've forgotten that the firmware's maker from openwrt-id has also posted their patch on the first page of this thread. So, scrolling down and can't you see the download links -- Download (IIX) or Download (int)?

Regarding the hardware revision, 2.0 and 2.1 differ only in the flash chip being used - different brand/vendor, but mostly the same spec-wise. The firmware should work on both revision. Just make sure that the checksum of the bin file downloaded is correct before flashing.

So, regarding your problem, upgrading to the latest TP-Link firmware can't help either? On TP-Link's website your 3G modem seems to be in the supported list. If it's not working reliably then shouldn't it be the problem of the vendor and shouldn't you reflect it to them, so that they could fix it ASAP?

Well, flashing to OpenWRT could solve your problem, but at the same time it could also introduce more problem (and headache). If you just want to make your 3G modem work with the router, I believe the OEM firmware is better suited for the task. Just email the vendor until they fix it.

So, if you still want to try your modem on OpenWRT maybe the following link could help?

[SOLVED] Vodafone K3805-Z for TL-MR3420

It's in Polish. Use online translation service if you need to. I use Google Translate.

78 (edited by Sila 2013-04-08 21:33:56)

Re: TP-Link TL-MR3420 V2 (2.1)

First Thanks again to all the people who are trying to help me!

I have spent dozens of hours on the OpenWRT project part alone. Plus countless hours on the problem itself. So be patient with me while I try to sort things out.

poisonz wrote:

Sorry, I've forgotten that the firmware's maker from openwrt-id has also posted their patch on the first page of this thread. So, scrolling down and can't you see the download links -- Download (IIX) or Download (int)?

Thanks but this version is the same as posted here and older than the trunk version I already tested. And I get the system itself working.
I am always struggling when it comes to connect the USB modem.

Keywords:

usb_modeswitch
unable to enumerate USB device on port [counting from 1-63]

USB disconnect, device number 24
usb 1-1: new high-speed USB device number 25 using ehci-platform
hub 1-0:1.0: unable to enumerate USB device on port 1
usb 1-1: new high-speed USB device number 26 using ehci-platform
...
usb-modeswitch: 1-1:1.0: Switching seemingly failed
usb-modeswitch: Switched to : 19d2:1001
usb-modeswitch: ProtoFind returns : 0
usb-modeswitch: Remove 1-1:1.0 19d2 1
usb-modeswitch: Remove 1-1 19d2 1
usb-modeswitch: 1-1:1.0: Manufacturer=Vodafone Product=K3805-z Serial=A2AC508E054BA4FFF0997AF98731FB90B87D0519 19d2 1001 1

The system seems to pull the USB device from usb_modeswitch again and again before it can do it's job.

And when the modeswitch works comes the garbled serial communication over usb_serial which makes the chat script fail.

poisonz wrote:

Regarding the hardware revision, 2.0 and 2.1 differ only in the flash chip being used - different brand/vendor, but mostly the same spec-wise. The firmware should work on both revision.

Good to know. Thanks.

poisonz wrote:

On TP-Link's website your 3G modem seems to be in the supported list.


Unfortunately it is not. I rechecked just now. If I google it I find it to be supported in Indonesia on a cached page. Go figure. I have tried to switch to Indonesia settings which didn't help either.

I have the TL-MR3040 (_3040_!) too which wasn't working reliably.
It could switch the modem and use it most of the time.
But it lost the Internet connection quite often telling me the modem was disconnected while it wasn't.
So I figured the follow-up modell would be able to use the modem too. Wrong thought.

poisonz wrote:

If you just want to make your 3G modem work with the router, I believe the OEM firmware is better suited for the task. Just email the vendor until they fix it.

I already did that before trying OpenWRT as a last resort.

The Chinese people were trying to help.
For instance they quoted a method of generating the binary files for the modem myself. Unfortunately they are using Windows XP only so their method doesn't work under WIndows 7.
I managed to find a way to create the USB sniffing protocols under Windows 7 myself using freely available and legal means. But I have no information about how to transform them into the binaries. Unfortunately the Chinese didn't understand what I was talking about when I detailed the method used under Windows 7.

So I revived a Windows XP Laptop and created the binaries there. The results were mixed and unreliable.
A bit like the modeswitch problems with OpenWRT: keep on rebooting router and modem cold and warm in various combinations and the modeswitch will work once sometime...

Then they gave me Beta Firmware to test which worked  for a week after several reboots.
Then it lost the Internet connection and the modem permanently and I gave up rebooting after a time.

poisonz wrote:

So, if you still want to try your modem on OpenWRT maybe the following link could help?

I will certainly work through that. Thanks!

I've been ready to give up so often now. But after one or two days I get another idea and HAVE to test it.

Yesterday I installed and tested the Blackwidow image from rFactory in Australia. Quite interesting build. Everything I need seems to be installed. And still 440KB free(!).
But the USB part has problems with the TP-Link K3805-Z too. They are a bit different though:

Manual Modeswitch attempt:
Looking for active driver ...
No driver found. Either detached before or never attached
...
Setting up communication with interface 0
Using endpoint 0x01 for message sending ...
Trying to send message 1 to endpoint 0x01 ...
OK, message successfully sent
Reading the response to message 1 (CSW) ...
Response reading got error -6
Device is gone, skipping any further commands

After a lot of back and forth booting of router and modem, un- and replug games:
Sep  8 17:08:10 OpenWrt kern.err kernel: [  200.790000] usbserial_generic 1-1:1.0: Generic device with no bulk out, not allowed.
Sep  8 17:08:10 OpenWrt kern.warn kernel: [  200.800000] usbserial_generic: probe of 1-1:1.0 failed with error -5
Sep  8 17:08:10 OpenWrt kern.info kernel: [  200.800000] cdc_acm 1-1:1.1: ttyACM0: USB ACM device
Sep  8 17:08:10 OpenWrt user.notice usb-modeswitch: 1-1:1.0: Manufacturer=Vodafone Product=K3805-z Serial=A2AC508E054BA4FFF0997AF98731FB90B87D0519 19d2 1003 0
Sep  8 17:08:11 OpenWrt user.notice usb-modeswitch: ProtoFind returns : 0
Sep  8 17:08:11 OpenWrt user.notice usb-modeswitch: 1-1:1.1: Manufacturer=Vodafone Product=K3805-z Serial=A2AC508E054BA4FFF0997AF98731FB90B87D0519 19d2 1003 1
Sep  8 17:08:11 OpenWrt user.notice usb-modeswitch: 1-1:1.2: Manufacturer=Vodafone Product=K3805-z Serial=A2AC508E054BA4FFF0997AF98731FB90B87D0519 19d2 1003 1

And a ttyACM0 device is created :-(.

Unswitched Vendor ID
             19d2
             Unswitched Product ID
             1003
             Switched Vendor ID
             19d2
             Switched Product ID
             1003
             Protocol Used
            
             Attached Drivers
            
No protocol or drivers attached.
I have tried 'serial' and 'option'.

So I will probably return to the trunk version.

Kind Regards.

79

Re: TP-Link TL-MR3420 V2 (2.1)

Hi guys,

Asking for some help. Totally new to openwrt and very little linux experience.
Trying to build own firmware for 3420 v2. Read wiki on topic.
Used "svn co svn://svn.openwrt.org/openwrt/branches/attitude_adjustment" to get sources.
Run make menuconfig. Can't find option for V2 hardware in target profile.
Alaways getting v1.bin files after compilation.

What am I doing wrong?

Thanks a lot in advance.

Re: TP-Link TL-MR3420 V2 (2.1)

must use trunk:

svn co svn://svn.openwrt.org/openwrt/trunk/

because your model it's not yet supported in the stable branch AA... dunno why....

https://forum.openwrt.org/viewtopic.php?pid=198103#p198103

81

Re: TP-Link TL-MR3420 V2 (2.1)

nebbia88 wrote:

must use trunk:

svn co svn://svn.openwrt.org/openwrt/trunk/

because your model it's not yet supported in the stable branch AA... dunno why....

https://forum.openwrt.org/viewtopic.php?pid=198103#p198103

thaks for reply

did like you said to get trunk version - still no sign of V2 in target profile of make menuconfig from trunk directory. What's wrong ?

Thanks.

Re: TP-Link TL-MR3420 V2 (2.1)

you should get both v1 and v2  images in bin dir when you build it..

Re: TP-Link TL-MR3420 V2 (2.1)

Hello guys,

I hope I am posting in the right spot. If not, please excuse me and please redirect me to where I should be asking this.
I also want to say that I'm not an expert in this field, but I like to try out new stuff.

I flashed the OpenWRT on my MR3420 v2 and after I tried a bit to get the 3G running with no success, I decided to go back to the original firmware and try some stuff there.

Needless to say that I am the proud owner of a shiny white brick. big_smile

I found a video that is exactly what my router looks like.
This is how the router is acting now.

I also found many tutorials about debricking MR3420, but they are all for v1.x.
Here is one of them.

So...
1. In the current state will I have a shot at debricking through serial cable (I have ordered this)?
2. Does the tutorial I found apply for v2 also? I'm not sure about the addresses used there. Do you guys know if v2 has the same memory layout as v1.x?
3. Until I get the adapter I was thinking about using this schematic since I have it already build for a project at work. Would this have a chance to work (given that I have serial port on an old PC)? I wouldn't risk bricking the router all the way.

Thank you,
Christian Glück

84

Re: TP-Link TL-MR3420 V2 (2.1)

@cristi.gluck: To answer your questions
1. yes
2. probably yes. yet you should verify the memory layout, once you entered the uboot prompt (ar7240>) by issuing the command "printenv". this should output a line stating where to boot from. if this is 9f020000 then you are good to proceed. or you can even follow the wiki entry: http://wiki.openwrt.org/toh/tp-link/tl-mr3420#using.a.serial.line
3. this looks good, as well. yet every piece in the chain may cause errors, so if it does not work then use the usb-serial adapter. or you can even try without serial using this method: http://wiki.openwrt.org/toh/tp-link/tl-mr3420#using.a.tftpd.server

Re: TP-Link TL-MR3420 V2 (2.1)

MBS wrote:

@cristi.gluck: To answer your questions
1. yes
2. probably yes. yet you should verify the memory layout, once you entered the uboot prompt (ar7240>) by issuing the command "printenv". this should output a line stating where to boot from. if this is 9f020000 then you are good to proceed. or you can even follow the wiki entry: http://wiki.openwrt.org/toh/tp-link/tl-mr3420#using.a.serial.line
3. this looks good, as well. yet every piece in the chain may cause errors, so if it does not work then use the usb-serial adapter. or you can even try without serial using this method: http://wiki.openwrt.org/toh/tp-link/tl-mr3420#using.a.tftpd.server

Many thanks for the fast response.

Failsafe doesn't work for me. Already tried it and no reaction, all the LED's keep blinking.
I will try this as soon as I have the chance and post here if successful.

Thank you!

86

Re: TP-Link TL-MR3420 V2 (2.1)

Actually, what I meant was not openwrt failsafe mode (since it probably won't work anyway). The interpretation of my last comment is that the bootloader is supposed to fetch a certain image via tftp, if the reset button is pressed and released during powerup. But I have no experience if that really works.

Re: TP-Link TL-MR3420 V2 (2.1)

MBS wrote:

@cristi.gluck: To answer your questions
1. yes
2. probably yes. yet you should verify the memory layout, once you entered the uboot prompt (ar7240>) by issuing the command "printenv". this should output a line stating where to boot from. if this is 9f020000 then you are good to proceed. or you can even follow the wiki entry: http://wiki.openwrt.org/toh/tp-link/tl-mr3420#using.a.serial.line
3. this looks good, as well. yet every piece in the chain may cause errors, so if it does not work then use the usb-serial adapter. or you can even try without serial using this method: http://wiki.openwrt.org/toh/tp-link/tl-mr3420#using.a.tftpd.server

Hello again,

I managed to connect the serial converter to the router, but I can't see anything on the serial console.
The converter works, since I can see the characters I send when I connect Tx and Rx together.

Also, using SerialMon, I could send the "tpl" command and the router stopped blinking, which tells me that somehow the command reached the router.

I put a 10k resistor between Tx and Vcc, but still no success.

Any ideas as to why the serial console is not working?

Thank you!

Re: TP-Link TL-MR3420 V2 (2.1)

Do you have a good gnd connection?
Is there really absolutely nothing coming back? If so your Tx on the router is not working.
If you have intermittent connections it could be Ground.

If you were using a 12V rs232 or similar I would expect the Rx on the router to burn out, but this is gut feeling, maybe it is the other way round.
What serial converter are you using?

89 (edited by nebbia88 2013-06-05 19:31:31)

Re: TP-Link TL-MR3420 V2 (2.1)

well, with a bit of luck you can unbrick just sending commands.. reading output is useful but not strictly necessary wink

Re: TP-Link TL-MR3420 V2 (2.1)

robthebrew wrote:

Do you have a good gnd connection?
Is there really absolutely nothing coming back? If so your Tx on the router is not working.
If you have intermittent connections it could be Ground.

If you were using a 12V rs232 or similar I would expect the Rx on the router to burn out, but this is gut feeling, maybe it is the other way round.
What serial converter are you using?

Hello,

Since the "tpl" command seems to go through, I guess the GND is fine, but I will check it to make sure.
I am using this serial converter.

There is absolutely nothing in the serial console.

Does this make any sense to you?

Thank you,
Christian Gluck

91

Re: TP-Link TL-MR3420 V2 (2.1)

It seems the signal levels between the router and your max3232 are not compatible. So, what I could imagine to solve the problem would be:
- use a usb serial that comes with 3.3V or
- replace the 10k resistor with a 4.7k one ore
- replace the 10k resistor with a 20k one.

Re: TP-Link TL-MR3420 V2 (2.1)

MBS wrote:

It seems the signal levels between the router and your max3232 are not compatible. So, what I could imagine to solve the problem would be:
- use a usb serial that comes with 3.3V or
- replace the 10k resistor with a 4.7k one ore
- replace the 10k resistor with a 20k one.

Hello,
I will try this later today.

I have already ordered this. I hope it's ok.
However, until I get it (it's from China and it takes a while for the package to get to me) I wanted to try to unbrick the router with a built adapter.

Thanks,
Christian Gluck

Re: TP-Link TL-MR3420 V2 (2.1)

MBS wrote:

It seems the signal levels between the router and your max3232 are not compatible. So, what I could imagine to solve the problem would be:
- use a usb serial that comes with 3.3V or
- replace the 10k resistor with a 4.7k one ore
- replace the 10k resistor with a 20k one.

Hello again,

I tried with 4.7k and 20k and still nothing.

If this was the last idea, then I guess I will have to wait until the USB adapter comes.

Thank you,
Christian Gluck

Re: TP-Link TL-MR3420 V2 (2.1)

Christi, did you see the bit about adding a 10K between Vcc and TX on the router, in the link you gave above?
Not adding that would explain why nothing comes back from the router.

Re: TP-Link TL-MR3420 V2 (2.1)

robthebrew wrote:

Christi, did you see the bit about adding a 10K between Vcc and TX on the router, in the link you gave above?
Not adding that would explain why nothing comes back from the router.

Hello,

Yes, I tried 10k, 4.7k and 20k between Tx and Vcc and I got nothing.
I connected the 10k/4.7k/20k between Tx and the Vcc of the router serial port (3.3V Vcc).

I will try to do this "in the dark" like nebbia88 posted above smile. Maybe I can do the flashing without getting anything back from the router smile.

Christian

96 (edited by cristi.gluck 2013-06-07 07:27:09)

Re: TP-Link TL-MR3420 V2 (2.1)

cristi.gluck wrote:
robthebrew wrote:

Christi, did you see the bit about adding a 10K between Vcc and TX on the router, in the link you gave above?
Not adding that would explain why nothing comes back from the router.

Hello,

Yes, I tried 10k, 4.7k and 20k between Tx and Vcc and I got nothing.
I connected the 10k/4.7k/20k between Tx and the Vcc of the router serial port (3.3V Vcc).

I will try to do this "in the dark" like nebbia88 posted above smile. Maybe I can do the flashing without getting anything back from the router smile.

Christian

I dug a bit more and came up with this...
http://dioptimizer.narod.ru/files/images/mr3420v2-uart-vs-jtag.jpg

So it looks like MR3420 also has a JTAG port, I just need to connect some wires.
Here is where I got this from, but I'm using Google Translate so I might get some info wrong... as far as I can see I just have to solder some wires to those 4 points and then use a JTAG adapter.
http://wiki.openwrt.org/ru/toh/tp-link/tl-mr3420.

Any clue if the cheapest adapter has any chance to work?
http://www.tiaowiki.com/wiki/images/a/a1/Sb5100.surfboard.webstar.gif.
I know parallel port is slow, REALLY slow, but at least this is cheap and I can build it quickly.

I want to use JTAG only as last resort, but it's worth to investigate this while trying something else.

Christian

Re: TP-Link TL-MR3420 V2 (2.1)

cristi.gluck
Try one more resistor on Rx and VCC line:
http://prohardver.hu/dl/upc/2011-09/280405_routerdku-5_interface.jpg
Source

98 (edited by cristi.gluck 2013-06-07 11:23:10)

Re: TP-Link TL-MR3420 V2 (2.1)

Dioptimizer wrote:

cristi.gluck
Try one more resistor on Rx and VCC line:
-- image removed --
Source

Hello,

I already tried this.

Investigating a bit further, I got a scope connected to the router Tx pin and I got the voltage levels.

It seems that my adapter uses ~0V for "0" and ~3.3V for "1".
The router on the other hand, only has ~2.6V for "0" and ~2.8 - 3.0V for "1" depending on what resistor I am using.
For a 4.7k resistor I had ~2.6V for "0" and ~3.0V for "1".

I attached screenshots from scope... see below.

So, I guess it's safe to say that the Tx pin works, it's just not compatible with my adapter, thefore the adapter doesn't detect any zeros in the communication since the voltage does not go below ~2.6V.

Any ideas on how to "adapt" them? smile

P.S. Sory for posting so many images, but I wanted to make everything as clear to see as possible.

Adapter scope screenshots

Adapter with No PullUp connected - overview.
http://imageshack.us/a/img13/543/adapternopuoverview.th.png
Adapter with No PullUp connected - zoom.
http://imageshack.us/a/img109/2503/adapternopuzoom.th.png


Adapter with 10k PullUp connected - overview.
http://imageshack.us/a/img17/8423/adapter10koverview.th.png
Adapter with 10k PullUp connected - zoom.
http://imageshack.us/a/img443/1749/adapter10kzoom.th.png


Adapter with 20k PullUp connected - overview.
http://imageshack.us/a/img401/7021/adapter20koverview.th.png
Adapter with 20k PullUp connected - zoom.
http://imageshack.us/a/img18/6066/adapter20kzoom.th.png


Router scope screenshots

Router with No PullUp connected - overview.
http://imageshack.us/a/img855/4569/routernopuoverview.th.png
Router with No PullUp connected - zoom.
http://imageshack.us/a/img22/7016/routernopuzoom.th.png


Router with 4.7k PullUp connected - overview.
http://imageshack.us/a/img266/550/router47koverview.th.png
Router with 4.7k PullUp connected - zoom.
http://imageshack.us/a/img543/2122/router47kzoom.th.png


Router with 10k PullUp connected - overview.
http://imageshack.us/a/img221/7503/router10koverview.th.png
Router with 10k PullUp connected - zoom.
http://imageshack.us/a/img822/2503/router10kzoom.th.png


Router with 20k PullUp connected - overview.
http://imageshack.us/a/img836/7559/router20koverview.th.png
Router with 20k PullUp connected - zoom.
http://imageshack.us/a/img823/5632/router20kzoom.th.png

Re: TP-Link TL-MR3420 V2 (2.1)

The ttl levels for 0 are not of any spec I recognise. I'm wondering what would happen if you pull-down to GND with a 10K: that should fix the 0 level. Evidently the 1 level does not need a pull-up, as the signal is in spec even with no resistor.

Re: TP-Link TL-MR3420 V2 (2.1)

robthebrew wrote:

The ttl levels for 0 are not of any spec I recognise. I'm wondering what would happen if you pull-down to GND with a 10K: that should fix the 0 level. Evidently the 1 level does not need a pull-up, as the signal is in spec even with no resistor.

Already tried with a 4.7k PullDown and the signal from the router is now ~700mV for "0" and ~2.8V for "1".

I will check the communication and come back if it's a success.