FiPy LTE modem firmware update failed

[Hamed Talebi]

Hi,

I have got a 1nce sim card recently and tried to update LTE modem firmware on FiPy. I followed the instructions from this link and successfully updated the modem to CAT-M1 5.2-48829 then tried some examples and afterward changed the modem firmware to NB-IoT NB1-41019 and tried the same examples. Everything worked smoothly but because NB-IoT has a longer attach() time I have decided to go back to CAT-M1 when I tried:

sqnsupgrade.run('/sd/CATM1-5.2-48829-1.dup', load_fff=False)

it crashed on the resetting phase and went back to the command line. I have tried to execute it again without any success, then spent hours and found lots of threads on the forum but none of them helped to get it to work. Following are some of the outputs I get from REPL:

>>> from network import LTE
>>> lte=LTE()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OSError: Couldn't start connection to Modem (modem_state=disconnected)
>>> 

>>> import sqnsupgrade
>>> sqnsupgrade.info(debug=True)
<<< Welcome to the SQN3330 firmware updater [1.2.6] >>>
>>> FiPy with firmware version 1.20.3.b4
The current delay is 1000
Response (+++ #1): b'\x00'
Response (AT #1) None
Response (AT #3) b'\x00'
Response (AT #4) None
Response (AT #1 @ 115200) b'\x00'
Response (AT #2 @ 115200) None
The current delay is 2000
Response (+++ #1): b'\x00'
Response (AT #1) None
Response (AT #3) b'\x00'
Response (AT #4) b'\x00'
Response (AT #1 @ 115200) b'\x00'
Response (AT #2 @ 115200) b'\x00'
The current delay is 3000
Response (+++ #1): None
Response (AT #1) None
Response (AT #3) b'\x00\x00'
Response (AT #4) b'\x00'
Response (AT #1 @ 115200) b'\x00\x00'
Response (AT #2 @ 115200) b'\x00'
The current delay is 4000
Response (+++ #1): b'\x00'
Response (AT #1) None
Response (AT #3) b'\xfe\x00\x00\x00'
Response (AT #4) b'\x00\xff\x00'
Response (AT #1 @ 115200) b'\x00\x00'
Response (AT #2 @ 115200) b'\x00\x00'
The current delay is 5000
Response (+++ #1): None
Response (AT #1) b'\x00'
Response (AT #2) None
Response (+++ #2): None
Response (AT #3) b'\x00\x00\x00'
Response (AT #4) b'\x00\x00'
Response (AT #1 @ 115200) b'\x00\x00\x00'
Response (AT #2 @ 115200) b'\x00\x00'
Modem state: None
Cannot determine modem state!
>>> 

>>> pycom.lte_modem_en_on_boot()
True
>>> 

I have set it to False and tried but still no answer.

>>> sqnsupgrade.run('/sd/CATM1-5.2-48829-1.dup', load_fff=False)
<<< Welcome to the SQN3330 firmware updater [1.2.6] >>>
>>> FiPy with firmware version 1.20.3.b4
Could not detect your modem!
Please try to power off your device and restart in safeboot mode.
Attempting AT wakeup...
True
>>> 

I have also reset into safeboot mode and got the same message.