Sierra EM7455 no recognized on router WE826[16M] with OpenWrt 18.06

Installing and Using OpenWrt
1

Hello,

I integrated the 4G card EM7455 before flash the system OpenWRT in a WE826 16M router.


4G cards pecifications :
Sierra Wireless AirPrime TM
Model : EM7455 QUALCOMM_4G
Product in Vietnam
LF716589960410
4428791000015A2040
442879100015 Windows
02.24.03.00 NO_GPS_1.0

On the web OpenWRT information interface :
MODEM > DEBUG INFO > DEVICE INFORMATION

############################################################
Device Information
T: Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=480 MxCh= 1
B: Alloc= 0/800 us ( 0%), #Int= 1, #Iso= 0
D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=1d6b ProdID=0002 Rev= 4.14
S: Manufacturer=Linux 4.14.63 ehci_hcd
S: Product=EHCI Host Controller
S: SerialNumber=101c0000.ehci
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
E: Ad=81(I) Atr=03(Int.) MxPS= 4 Ivl=256ms
************************************************************
T: Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=480 MxCh= 4
D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=01 MxPS=64 #Cfgs= 1
P: Vendor=05e3 ProdID=0608 Rev=85.37
S: Product=USB2.0 Hub
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=100mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
E: Ad=81(I) Atr=03(Int.) MxPS= 1 Ivl=256ms
************************************************************
T: Bus=02 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=12 MxCh= 1
B: Alloc= 0/900 us ( 0%), #Int= 0, #Iso= 0
D: Ver= 1.10 Cls=09(hub ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=1d6b ProdID=0001 Rev= 4.14
S: Manufacturer=Linux 4.14.63 ohci_hcd
S: Product=Generic Platform OHCI controller
S: SerialNumber=101c1000.ohci
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
E: Ad=81(I) Atr=03(Int.) MxPS= 2 Ivl=255ms
############################################################

On a post from another forum, Jim was talking about a possible line of approach : "the possibility that the VID and PID may need to be changed to work properly"?

On the WE826, what is it showing under the MODEM > DEBUG INFO > DEVICE INFORMATION
Image
https://drive.google.com/open?id=1mtC4j ... DbcCx6wP8M

The Sierra "Linux QMI SDK Software" was already download :
SLQS04.00.20.bin.tar [gz] 277.4MB
SLQS04.00.20-lite.bin.tar [gz] 79.7MB

Is it necessary to do a high level linux kernel compilation ?
Is it possible with SSH to fix the problem in command lines ?
Is it possible to download and install a package from OpenWRT web interface SYSTEM>SOFTWARE ?
Is it necessary to use my laptop to flash the Sierra EM7455 card ?

Please, how it's possible to install that card because several users found the good configuration on several forums ?

Thank you for your time

Nicolas

2

I don't see the EM7455 in the USB devices at all. It should be there even if there is no driver attached.

Is it getting sufficient power?

Does the socket you have it plugged into support its USB pin configuration?

3

It's a QMI device, but if I recall, Sierra has a couple of AT commands that need to be sent over to get it fully online - it's been a long time, but once sorted, they're very good,

uqmi in openwrt is still a bit rough based on LTE integration with a different vendor - modemmanger-openwrt is an alternative, and it pulls in most of the drivers needed, but it's a bit of a flash/memory hog due to libgl2.0

Using the Qualcomm/Vendors drivers for the private interfaces is a bit of a exercise - check codeaurora for the qualcomm code that the vendors base their drivers on - it can be done, but much of the QCOM source is based on older kernels -

4

Thank you Jeff and sfx2000,

Jim on an other forum already ask me to send the AT command, unless if I mistaken with the SSH terminal :

OpenWrt 18.06.1, r7258-5eb055306f

root@ROOter:~# ATI
-ash: ATI: not found
root@ROOter:~# at
-ash: at: not found
root@ROOter:~# ati
-ash: ati: not found

The AT command line gave nothing.
What is the package necessary to install this program which allow to do the SSH "AT" command line ?

Thank you for your time

5

Is it necessary to flash the memory to install the package :
sudo apt-get install libglib2.0-dev ?

If yes, others actions are requested after install that package ?

6

Couple of items you might find handy

usb-utils
minicom

both are in the packages, so install them - usb-utils is handy as you can then run lsusb, and you should see probably 3 endpoints from the sierra device - one will be a traditional comm port (/dev/ttyUSB0 sometimes), one is a diagnostic/control endpoint (/dev/ttyUSB1), and a QMI WDM endpoint, which is like a USB network interface.

Don't rule out using uqmi - check the Wiki, many modems will work fine, but some are particular.

best of luck

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