OSError: Couldn't connect to Modem!

[tveito]

Hello.

We are trying to debug a problem we are having related to the LTE modem on the FiPy.

When pycom.lte_modem_en_on_boot() is set to False we are experiencing that we can not start LTE communication at all after a reset (deepsleep, machine.reset or button), but not after power cycling the device. As far as I understand, this flag should only stop the LTE modem from starting up every boot, but should not disable it all together. Will not post the entire code where we have done most of our testing with (too many files), but have created a simplified version that we have been able to reproduce it with:

from network import LTE
import pycom
import time
import machine

if pycom.lte_modem_en_on_boot():
    print("LTE on boot was enabled. Disabling.")
    pycom.lte_modem_en_on_boot(False)

lte = LTE()


print("got lte!")
time.sleep(10)
machine.reset()

expected output when doing a "soft" reset: "OSError: Couldn't connect to Modem!"
expected output after powercycle: "got lte"

fipy firmware: 1.18.2.r7
modem firmware: LR5.1.1.0-41065

Any help or suggestions would be appreciated.

[Edward Dimmack]

@tveito Sorry for the late reply. I meant 1.18.2 with no revision update. So I had 1.18.2.r7 and it didn't work so I downgraded to 1.18.2 and it worked.

[diepducle]

@rskoniec Thank you for your support. I've already fixed this problem by upgrading the modem firmware.

Now I am trying to connect to Telstra network in Australia but I got stuck when lte is not attached, as shown in the picture below. Could you please help me to figure out this problem?

[rskoniec]

@diepducle Maybe clues from this thread would be helpful https://forum.pycom.io/topic/4022/unable-to-update-gpy-modem-firmware

[diepducle]

@rskoniec Thank you for your reply.

I tried to downgrade to some versions like: FiPy-1.18.2.r6, FiPy-1.18.2.r5, FiPy-1.18.2, FiPy-1.18.1.r7 but all show the same problem is that the triple arrows are disappeared.

When I upgrade to version FiPy-1.18.3 from the version FiPy-1.18.2.r7 (using), they show the problem of OSError: Couldn't connect to modem.

[rskoniec]

@diepducle Try with downgrade to https://software.pycom.io/downloads/FiPy-1.18.2.tar.gz or upgrade to https://software.pycom.io/downloads/FiPy-1.18.3.tar.gz Here is the full list of FiPy f/w https://software.pycom.io/downloads/FiPy.html

[diepducle]

@rskoniec By the way, before the firmware version 1.18.2.r7 being used, I used to upgraded the firmware to version 1.18.2.r6 [pybytes], and I got a different problem when entering the code "lte = LTE()" (as same as the following topic: https://forum.pycom.io/topic/3129/lte-lte-getting-stuck-after-reset-fw-1-17-3-b1-on-fipy). I wonder that which firmware version should I use and am I doing the right track.

[diepducle]

@rskoniec Thank you for your reply. I tried to use pycom.lte_modem_en_on_boot(False) but the result was still the same.

I am a newbie in this area and trying to send data to pybytes after this. But now I am struggling with LTE M1 connection. Could you please tell me the way to fix this problem? Many thanks!

[rskoniec]

@diepducle From the logic of your code/commands you want to disable pycom.lte_modem_en_on_boot if it's enabled so you shold use pycom.lte_modem_en_on_boot(False) or pycom.lte_modem_en_on_boot(0)

[diepducle]

@tveito Hi, I got the same problem here. My device has firmware version 1.18.2.v7. I did a reset but there is still stuck after entering the code "lte = LTE()". Please help me. Thank you!!

[tveito]

@Edward-Dimmack Hello and thanks for the response. Could you please give me the last part of the firmware? As my units did have firmware version 1.18.2.r7 (so still 1.18.2).

If anyone still have problems we have figured out a way of reliably turning on the modem:
When communicating set lte_modem_en_on_boot() to True.
Do a reset.
communicate.

This does however introduce the need to keep state between resets, but that can be done by ether checking if lte_modem_en_on_boot is set to True or by checking reset cause if you don't want to start using the eeprom.

[Edward Dimmack]

@rskoniec Thank you for that. I tried all the modem firmware and it seemed to have little effect. However, I changed the firmware version to version 1.18.2 on the FiPy and so far they are all working. Even the ones that weren't working at all. Not sure if it will work for anyone else and I haven't done thorough testing yet. Will update if anything changes.

[rskoniec]

@Edward-Dimmack said in OSError: Couldn't connect to Modem!:

(...) Maybe the Sequans firmware on the first device is different but I am not sure where to get an older firmware for the modem.

You can use my prv modem f/w repo

[Edward Dimmack]

I agree. I wasn't having this issue with the first device we bought so we bought 14 more and all 14 are having the same issue. Some intermittent and some simply never work. I need to try downgrading the firmware but other than that everything is the same. Maybe the Sequans firmware on the first device is different but I am not sure where to get an older firmware for the modem.

[PaulM]

@tveito It's insane that this thread never received a response from Pycom. I'm facing the same issue on the GPy which is entirely foreclosing usage of the one and only thing I bought the board for: LTE communications.