Cell Modem Tests

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Yang Wang

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Jan 26, 2017, 1:55:04 PM1/26/17
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Hello all,

I picked up ISOBlue2 dev again this week and I did some cell modem tests.

Surprisingly, the anticipated primary choice of cell modem: uBlox MCPI-L200 mini-PCIe module does not work that well. The modem cannot be recognized as a correct USB or serial device.

The secondary choice: Telit LE910-NAG mini-PCIe module works pretty well.

There are 2 ways to make the module work. Both methods require additional kernel features that the stock kernel Toradex does not provide for Apalis iMX6 and Ixora carrier board.

For flashing the kernel: http://developer.toradex.com/knowledge-base/build-u-boot-and-linux-kernel-from-source-code

1. PPP

Please refer to this page to setup the module: https://www.toradex.com/blog/how-to-use-gsm-3g-4g-in-embedded-linux-systems

In addition to the kernel configuration provided in this page, enable PPP support for async serial ports and USB driver for GSM and CDMA modems in kernel configuration as well.

If the modem is recognized by the kernel, 5 USB to serial interfaces will be created under /dev/ttyUSB* although /dev/ttyUSB2 is the primary port in my case.

Follow this link to set up the PPP connection.

After the PPP successfully connects to the network, you will most likely still need to manually configure your default gateway and your DNS nameserver.

And after all these, you should able to ping an IP or a web address.

2. qmicli

According to Telit's documentation, this is the official way to setup the module.

You need to have dhclient, libqmimodemmanager and preferably networkmanager installed.

Enable QMI WWAN driver for Qualcomm MSM based 3G and LTE modems in kernel configuration. Recompile and flash the kernel onto the board.

If the modem is recognized successfully, you have a /dev/cdc-wdm0.

Then, do:

qmicli -p -d /dev/cdc-wdm0 --wds-start-network=yourAPN --client-no-release-cid

If the above command doesn't return any error, you will have a network interface named wwan0 with an assigned IP. After that you will just run:

dhclient wwan0

Then you should be able to ping an IP and a web address.

Regards,
Yang






Rifo Turs

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Jan 27, 2017, 11:22:30 AM1/27/17
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Hello Yang,

Thanks for reporting your findings. I was actually going to spend some time with the uBlox modem tomorrow. Now reading your post, I will switch to Telit then. 

I am planning to use 3G in europe frequencies. I will check and see which model I should use.

thanks
rifo

26 Ocak 2017 Perşembe 21:55:04 UTC+3 tarihinde Yang Wang yazdı:

Rifo Turs

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Jan 27, 2017, 1:51:18 PM1/27/17
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Hello again Yang,

I have checked the prices of Telit modules and they seem to me almost twice the price of ublox mcpi-l200 modules. I'll try to contact the ublox forum and try to get some support. In the mean time can you please tell me what went wrong? I can try to ask the problems you faced to ublox forum


26 Ocak 2017 Perşembe 21:55:04 UTC+3 tarihinde Yang Wang yazdı:
Hello all,

Yang Wang

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Jan 27, 2017, 2:54:33 PM1/27/17
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Hi Rifo,

The Telit module I purchased was from here: https://shop.dcsbusiness.com/product/le910-mini-pcie/

It is the actually cheaper than the uBlox module.

I also just checked the price for uBlox's MPCI-L200, it went from $119 (the price when I purchased it) to $299. Don't know what happened there.

About the uBlox module:

modemmanager can detect the module fine but when I try using either PPP or qmicli to have it connect to the network, both programs threw some error and when I searched online, there wasn't any useful tips for a quick fix so I just switched to the Telit module.

Rifo Turs

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Jan 28, 2017, 2:02:26 AM1/28/17
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Hello Yang,

Something fishy is going on here :)  I will check the le910-mini-pcie again, here I found a place that sells it online but it costs around 150$

About ublox module, I may be mistaken but on digikey, it is sold for 85$.  Can you please check whether the below link is the same module that you are using?


thanks
rifo

27 Ocak 2017 Cuma 22:54:33 UTC+3 tarihinde Yang Wang yazdı:

Yang Wang

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Jan 28, 2017, 2:47:29 PM1/28/17
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Yep, that's what I have. Don't forget to buy antennas; otherwise, it will not work entirely.

Rifo Turs

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May 1, 2017, 8:59:00 AM5/1/17
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Hello Yang,

I have also decided to switch to telit modem (I wasn't able to have ublox modem working)

Can you please tell how you installed the necessary libraries, libqmi, modemManager and networkManager?

thanks a lot
rifo

28 Ocak 2017 Cumartesi 22:47:29 UTC+3 tarihinde Yang Wang yazdı:

Yang Wang

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May 1, 2017, 10:51:35 AM5/1/17
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Hello Rifo,

A brief walk-through on the software packages needed as well as the commands were provided in the original post of this thread.

These three packages should be available for various Linux distributions. You should be able to google instructions on how to install them.

Let me know if you run into issues.

Regards,
Yang

Rifo Turs

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May 3, 2017, 3:02:03 AM5/3/17
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Hello Yang,

I was able to install the libraries and the kernel driver but couldn't get the Telit modem as /dev/cdc-wdm0
The module I have is HE910-D, (if I am not wrong, it's the commercial version of HE920) 
I guess I need the cdc-ether driver. I will give it a shot on friday, if I fail :( then I'll go with ppp option.

Between, openembedded and angstrom are both new to me, I thought of making a short documentation about the 
libraries and kernel, I'll post it here. It may be handy later on


1 Mayıs 2017 Pazartesi 17:51:35 UTC+3 tarihinde Yang Wang yazdı:

Yang Wang

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May 3, 2017, 12:27:20 PM5/3/17
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Hi Rifo,

This is the kernel option that I enabled when bitbaking my kernel:


I maintained two repos for bitbake recipes for building ISOBlue2 software and image along with Toradex's recipes for board specific recipes and software:



Currently I need to sync Toradex's stuff first (instructions) and then include my two repos with the right file architecture so that it will make an ISOBlue2 image. When I have enough time, I will make the bitbake process as simple as possible for making an ISOBlue2 image and document this process. It will be great if you want to make some documentations as well!

Regards,
Yang
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