USSD for Mudi GL-E750

Bpz1970 · 2022-09-19T12:10:07.185Z

Hello. After quite few months later, I’m still unable to deal with USSD queries using the EG25-G modem, even with the new firmware update provided by Alzhao. I’m beginning to believe that this module can’t support USSD.
I hope I’m wrong.

alzhao · 2022-09-19T13:06:06.267Z

As I said I could do that in my side.

Seems this is related to carrier network. It can also be bug in the modem firmware.

I can send modem firmware update if that is something you can try.

m0n5t3r · 2022-10-23T11:55:11.074Z

since this seems to be the USSD thread… I have the GL-E750 with an EP06-E; AT+CUSD=1,"<request>", 15 seems to work (as in, if the request is a simple “get credit” for my carrier I get the info by SMS), but I can’t find a way to get the actual USSD response, and docs are, well, poorly written (at least the random AWS hosted pdf file I found - if I understand [1] correctly, AT+CUSD? should return the response).

Is this a firmware bug? is there any way to get a newer firmware version? I see there’s a quec_upload binary in the firmware, so I suppose the update mechanism used by, say, the pinephone (it has an EG25 inside) should work, but I have to ask.

However, quectel has no firmware download page that I can find (random employees upload files to baidu or sharepoint and post links in their forum when someone asks), and the version numbers are baffling - it’s hard to figure out which is newer and which will even work - came across one named EP06ELAR04A05M4G - what differs looks like a higher number (04A05 vs 03A08), but I’m not sure (and would need a backup of the old firmware to revert anyway, just in case it’s bad)

edit: after an attempt to make openwrt use qmi (failed with some unhelpful access denied errors in logs) USSD requests stopped working, I get +CME ERROR: 30 (but AT+QUSD? replies with +CUSD: 1 followed by OK - router reboot and modem reset don’t seem to help

even later edit: ok, qmi works now (changed the interface from the gl-inet UI instead of switching protocol in luci - no idea what it does differently), USSD still not working

[1] For an USSD response from the network, or a network initiated operation, the format is: +CUSD: <status>[,<rspstr>,[<dcs>]].

alzhao · 2022-10-24T08:42:18.510Z

I cannot speak for Quectel of how they can manage firmware for public.

But if you want to try I have a newer firmware and I can send guide to you. Just pm me or email me.

m0n5t3r · 2022-10-24T14:31:49.064Z

first off, looks like error 30 means “no network service” and was caused by me setting AT+QCFG="nwscanmode",3 in an attempt to squeeze some speed out of the connection - turns out it needs to be 0 or USSD doesn’t work

next up, thanks for the firmware, I’m not really sure it fixed USSD (it did add a few Mbps to the downstream connection speed, I think): the web UI doesn’t wait for the whole response to be printed, so it only returns what gets printed immediately; the way AT+CUSD seems to work is you get an OK to indicate the command was a success, and then about 1s later you get the response from the network, like +CUSD: 0,"You'll receive an SMS with the information you requested.",15

BTW, the serial port seems to be multiplexed between several things, if I leave picocom running there’s a lot of replies to commands other than the ones I’ve entered. I suppose I can work around this if I make a script (have chat expect +CUSD, for instance) - I’d really like to be able to recharge the credit, and this involves a bit of navigation through a menu.

admon · 2024-08-24T19:06:19.649Z

delete:

Can GL-inet publish a method for updating the firmware (modem firmware not router firmware) ?

Here you go: Upgrade Quectel Module Software - GL.iNet Router Docs 4

ywp · 2024-08-26T01:30:20.350Z

We do not currently support USSD short code sending
Subsequent versions need to be evaluated for development
thank you

alzhao · 2024-08-27T08:02:07.368Z

delete:

Unfortunately no response to what firmware is newer and which one is know to work vs which

Pls post your firmware so that we can check.

delete:

Unfortunately the customer before me didn't share all his steps.

If you go back to the first post of this thread, you will see that he used AT command to send short code.

john718 · 2024-10-05T18:49:29.093Z

Anyone? (See last post)

alzhao · 2024-10-07T10:04:05.792Z

Cannot find your first post.

What is your modem model?

ywp · 2024-10-08T01:37:49.592Z

web pages currently do not support USSD
Follow-up consideration whether to add

john718 · 2024-10-09T20:08:07.560Z

Mudi 2

Should I use minicom on the TTY instead of issuing "gl_modem AT code" ?

Because the network takes a sec before giving balance information and gl_modem quits immediately... (It has no 'chat' function)

john718 · 2024-10-09T20:10:50.238Z

Maybe add a 1--2 second delay to catch any additional responses from the network? I assume the web interface just uses the gl_modem binary?

You can make it delay only when a USSD type AT code is issued.

ywp · 2024-10-10T01:42:11.267Z

Of course we thought about it, but it's not realistic

john718 · 2024-10-10T20:17:46.795Z

You probably have a better way to support USSD in the future. I trust your expertise. Eagerly waiting for new models its a cool product.

admon · 2024-10-10T20:24:01.880Z

XE3000 - less portable, way more powerful

EvolvePlease · 2025-06-06T07:21:33.258Z

@ywp @alzhao @admon @m0n5t3r

Did this issue reach any conclusion?

I need to run USSD commands from Mudi with modem Quectel EM060K-GL revision EM060KGLAAR01A11M2G.

Thanks!

Cathy · 2025-06-10T02:51:34.738Z

Hello, sorry for that Mudi V2 doesn't support USSD commands.

EvolvePlease · 2025-06-10T04:43:46.851Z

d4daeef98097e09520bf689748d86e092560×1694 223 KB

Hello Cathy, thank you for your response.

Of course Mudi supports USSD codes. See attached photo evidence.

USSD works if you force a 3G connection and enter a valid USSD code three times (while hopping on left foot).

USSD (and the modem interface, in general) is shockingly unreliable - perhaps GL has the intention to resolve this and make USSD more accessible?

Thank you.

Cathy · 2025-06-11T03:25:05.932Z

Hi, USSD commands will cause other AT commands processing errors and affect the network service. Currently the GL GUI does not support USSD commands. Regarding the USSD requirement, we need to consider and evaluate it. Thanks