DWM-222 rev A2

Rogan Dawes rogan at dawes.za.net
Tue Oct 30 10:27:21 UTC 2018

Hi Domi,

Actually, you are correct, my shields do look like they are "press
fit" onto a cage. I'm hoping that I can find a UART on the test
points, though, before I start pulling the shields off.

I did some initial probing with the scope, and only found constant 1v8
on some, and constant ground on others. Nothing that suggested UART
activity, unfortunately. That said, I was not "rebooting" between each
point, so the device may have settled down by the time I tested the TX

I'll be grabbing a foot switch, so I can reset the modem while probing
each point, hopefully that will give better results!

I'm happy to try your firmware, to see if I can get ADB working. How
would I check if it can be accessed/enabled? As mentioned, I only get
the 5 ttyUSB devices (and get no response to an AT command on any of

My end goal, though, is to have a completely standalone Linux
computer, accessible from the Internet, that can present a variety of
different USB gadget profiles to its host. So, while ADB would assist
in probing the capabilities of the built-in firmware, it would be
superfluous in the long run.


On Tue, Oct 30, 2018 at 11:25 AM Tomcsányi Domonkos <domi at tomcsanyi.net> wrote:
> Hello Rogan,
> I'm the author of the Wiki page about the stick.
> https://osmocom.org/projects/quectel-modems/wiki/D-Link_DWM-222_stick
> I am really glad to see some interest in the device.
> Do you have ADB access, or that has already been disabled?
> You could try to flash a new firmware on the device, using the provided flasher application (Windows only). Would you be open to run the firmware updater tool with my modified rootfs, that would enable ADB for the stick?
> I think the A1 firmware is compatible, but I cannot say for sure. All I know is that my stick's LED doesn't properly do status indication since I run the upgrade, but otherwise it functions as a modem.
> I'd be happy to co-operate on this project, because I think it is quite interesting.
> About the shields: as it could be seen on the pictures I just lifted the metal with a screewdriver to reveal the chips. The A2 has those maybe soldered on?
> Also I just noticed D-Link has released 2 new firmwares since I last checked. I will see if I can somehow update my dongle from the current semi-broken state.
> Cheers,
> Domi
> 2018. okt. 30. dátummal, 9:43 időpontban Rogan Dawes <rogan at dawes.za.net> írta:
> Hi folks,
> I have purchased a DLink DWM-222 with the intention of exploring the
> Linux OS running inside it, and if possible, compiling some additional
> USB gadgets to use with it.
> FWIW, the USB ID's are 2001:ac01 before modeswitch, and 2001:7e3d
> after switching.
> It creates ttyUSB[0-4] when switched, and the VID:PID added to the
> option driver.
> I was wondering if there had been any further developments in the
> exploration of the A1 hardware or firmware, in terms of gaining a
> shell on the device at all without soldering?
> Some initial probing has shown some 1.8v signals on some of the test
> points, so I will check those with a scope while booting to see if I
> can identify some waveforms, hopefully indicating a UART. I do have a
> FTDI UART with a voltage reference, so I am fairly confident that I
> can access those signals without damaging the device once identified.
> Unfortunately, the updated hardware has complete shields over the
> interesting bits, so I cannot identify chips, etc. I have also not
> been able to find firmware for the A2, the only firmware I could find
> was at ftp://ftp.d-link.co.za/DWM/dwm222/Firmware/, marked as A1. I'll
> check to see if they are compatible. And of course, will be copying
> the driver software from the embedded CDROM.
> Regards,
> Rogan
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