Raspbian and PCI cellular

balenaFin
1

Hi,
Is there any guide out there to help with connecting the PCI cellular modem on a Raspbian for FIN?

Thanks,

4

Hi @saoron

We do have a good blog post on how to use the modem with balenaOS

But the raspbian question is an interesting one. As the Pi doesn’t have a PCIe interface, there won’t be a blog out there. You might find more luck searching for how a normal linux laptop with pci-e modems configure the modem. I imagine you should see the modem using lspci and/or lsusb. And modem manager should pick it up…

Regards
ZubairLK

6

Just received a bit of info internally. The modem should show up as a regular usb cellular modem. So install NetworkManager and ModemManager and they should pick it up.

8

e.g. https://blog.soracom.io/beginners-guide-to-iot-cellular-connectivity-on-raspberry-pi-and-linux-devices-55d4f7489adf should be helpful

9

Thank you so much for the detailed answers, I’ll post back when I get this to work.

12

Hi, I was able to see the modem with mmcli, but it looks like it does not detect the Sim card, any advise here?

Here’s the log of >mmcli -m 0

/org/freedesktop/ModemManager1/Modem/0 (device id ‘6f28660af8c8de90ce20e13ef672ac94acbde1f2’)

Hardware | manufacturer: ‘QUALCOMM INCORPORATED’
| model: ‘QUECTEL Mobile Broadband Module’
| revision: ‘EC25EFAR06A03M4G’
| supported: ‘gsm-umts
| lte
| gsm-umts, lte’
| current: ‘gsm-umts, lte’
| equipment id: ‘866758044484067’

System | device: ‘/sys/devices/platform/soc/3f980000.usb/usb1/1-1/1-1.2’
| drivers: ‘option1, qmi_wwan’
| plugin: ‘Generic’
| primary port: ‘cdc-wdm0’
| ports: ‘ttyUSB0 (qcdm), ttyUSB2 (at), cdc-wdm0 (qmi), wwan0 (net), ttyUSB3 (at)’

Numbers | own : ‘unknown’

Status | lock: ‘unknown’
| unlock retries: ‘unknown’
| state: ‘failed’
| failed reason: ‘sim-missing’
| power state: ‘unknown’
| access tech: ‘unknown’
| signal quality: ‘0’ (cached)

Modes | supported: ‘allowed: 2g, 3g, 4g; preferred: none’
| current: ‘allowed: any; preferred: none’

Bands | supported: ‘unknown’
| current: ‘unknown’

IP | supported: ‘ipv4, ipv6, ipv4v6’

SIM | path: ‘none’

Bearers | paths: ‘none’

13

Hi @saoron , is sim card on the pcie modem on in the fin sim slot? Also which fin version do you have ?

15

Sim is on the Fin slot, Fin v1.1

16

Thanks for the info @saoron , I’m checking with the fin team if there is a good way to troubleshoot this. I know we have seen at least 1 or 2 instances where the sim slot was not soldered down perfectly and we had to ship out a replacement. Hopefully this is not the case on your board. Can you ensure the sim is firmly set in the slot. It also would be interesting to test a second sim if you have one on hand?

18

Actually when I use Balena OS the module connects and everything works as expected, Only on Raspbian I get the “no-sim” error.

19

hmm, @saoron when running with raspbian, what do you see on the i2c bus? from what i remember the sim card is on an i2c bus and i wonder if on raspbian it perhaps isn’t enabled by default.

22

@shaunmulligan thanks for the tip, I’ve enabled i2c but it still get error: “sim-missing”.

Any ideas?

31

Hey @saoron

The SIM card slot is electrically connected directly to the mini PCIe slot on the balenaFin (you can see this in the schematics here if you’re interested). This means there’s nothing with regard to the SIM connection that is software controlled and so nothing in that regard can change between balenaOS and Raspbian.

The only difference can be how the OS is handling the modem. I’ve just tested mine here with Raspbian lite and after installing ModemManager and rebooting I can see the device with the SIM card - but I don’t have the exact model of modem that you have to compare with. I would be interested to see the lsusb output from your balenaOS installation and then again from the Raspbian installation to check they are the same.

34

Hello - are there any updates on this issue? I have installed a EC-25A modem with a GSM SIM card in a v1.1 BalenaFIN board slot, as well as Modem Manager. I am receiving the “sim-missing” message from “sudo mmcli -m 0” as well. I am running Raspbian downloaded from Balena (but not updated, as the wireless connection gets lost per another post and my own experience).

My “lsusb” device listing does not show the modem (mouse, keyboard, ethernet adapter, hub, LInux root hub are all shown).

Am I missing something?

Thanks in advance!

35

Hi, thanks for getting back to us! A lot of things happened since then, I believe our pipeline of producing those Raspbian images for the Fin had had some changes since. Will check with our team, and get back to you in a bit!

37

Hi, do you install NetworkManager/ModemManager yourself, right? Does the EC-25A have a SIM card slot? You have the SIM card in the the Fin’s SIM card slot or in the modem’s (if it has)? What does sudo mmcli -L say? Just trying to collect information for our debugging.

39

Also, one hunch we have, that the SIM card on the Fin is communicating with the modem over I2C, maybe I2C is not enabled on this device? Can you copy out the contents of your config.txt file? (I think it’s in /boot?) Thanks!

41

Sorry for the many updates, our team is discussing this case, and the ideas keep coming. Correction for the previous message, that I2C is a separate bus, so it should not be affected by configuration.

If you see the modem (with mmcli -L) but not the SIM card, our current guess is that either the SIM or the SIM slot is broken. Have you tried the SIM card in e.g. a (smart)phone, that it works/connects? If that works, then the SIM slot is suspect on the device. If you have more than one Fin, that would be a good check as well, whether it works the same way in all of them.
If the issue is the slot, we will likely do device replacement for you. Just checking all the angles, as the simplest/fastest would be getting it to work for you.

Thanks!

43

@imrehg - Thanks for the quick response! I’ll try to answer all of these for you:

  • Raspbian image - I am using the latest v1.1 (without updates permy earlier message) on a v1.1 board.
  • I specifically installed Modem Manager. Not Network Manager, as that has caused issues with our use case in the past.
  • SIM card is on the FIN board.
  • sudo mmcli -L output:
pi@raspberrypi:~ $ sudo mmcli -L

Found 1 modems:
	/org/freedesktop/ModemManager1/Modem/0 [QUALCOMM INCORPORATED] QUECTEL Mobile Broadband Module
----------------------------------------------------------------------------
- Config.txt:
--------------------------------------------------------------------------
> # For more options and information see
> # http://rpf.io/configtxt
> # Some settings may impact device functionality. See link above for details
> 
> # uncomment if you get no picture on HDMI for a default "safe" mode
> #hdmi_safe=1
> 
> # uncomment this if your display has a black border of unused pixels visible
> # and your display can output without overscan
> #disable_overscan=1
> 
> # uncomment the following to adjust overscan. Use positive numbers if console
> # goes off screen, and negative if there is too much border
> #overscan_left=16
> #overscan_right=16
> #overscan_top=16
> #overscan_bottom=16
> 
> # uncomment to force a console size. By default it will be display's size minus
> # overscan.
> #framebuffer_width=1280
> #framebuffer_height=720
> 
> # uncomment if hdmi display is not detected and composite is being output
> #hdmi_force_hotplug=1
> 
> # uncomment to force a specific HDMI mode (this will force VGA)
> #hdmi_group=1
> #hdmi_mode=1
> 
> # uncomment to force a HDMI mode rather than DVI. This can make audio work in
> # DMT (computer monitor) modes
> #hdmi_drive=2
> 
> # uncomment to increase signal to HDMI, if you have interference, blanking, or
> # no display
> #config_hdmi_boost=4
> 
> # uncomment for composite PAL
> #sdtv_mode=2
> 
> #uncomment to overclock the arm. 700 MHz is the default.
> #arm_freq=800
> 
> # Uncomment some or all of these to enable the optional hardware interfaces
> dtparam=i2c_arm=on
> #dtparam=i2s=on
> #dtparam=spi=on
> 
> # Uncomment this to enable the lirc-rpi module
> #dtoverlay=lirc-rpi
> 
> # Additional overlays and parameters are documented /boot/overlays/README
> 
> # Enable audio (loads snd_bcm2835)
> dtparam=audio=on
> dtoverlay=balena-fin-updated

(I2C is enabled currently)

  • SIM card is literally brand new, but I will try to get it installed in another device for testing.

Thanks

John

44

Hi @Jgilbert,

Please let us know the results of your tests with that SIM card in another device, as that will be very useful in determining the underlying issue!