GPy Modem unconnectable

[Jeff Brown]

Typical [unresolved] thread asking for help to recover an unconnectable modem:
link text

I have the same issue. I have noticed a few threads here referencing this error but see no resolution offered in any of them except to update the modem following the instructions here:link text

That is not possible in my case as all of the procedures require the modem be responsive.

Here's another thread on this topic that still seems to go unresolved: link text

Here is the output from attempting to recover modem in SafeBoot mode:

>>> from machine import SD
>>> import os
>>> 
>>> sd = SD()
>>> os.mount(sd, '/sd')
>>> import sqnsupgrade
>>> sqnsupgrade.run('/sd/CATM1-5.2-48829-1.dup', load_fff=False, debug=True)
<<< Welcome to the SQN3330 firmware updater [1.2.6] >>>
>>> GPy with firmware version 1.20.2.r2
File /sd/CATM1-5.2-48829-1.dup has size 416448
The current delay is 1000
Response (+++ #1): None
Response (AT #1) None
Response (AT #3) None
Response (AT #4) None
Response (AT #1 @ 115200) None
Response (AT #2 @ 115200) None
The current delay is 2000
Response (+++ #1): None
Response (AT #1) None
Response (AT #3) None
Response (AT #4) None
Response (AT #1 @ 115200) None
Response (AT #2 @ 115200) None
The current delay is 3000
Response (+++ #1): None
Response (AT #1) None
Response (AT #3) None
Response (AT #4) None
Response (AT #1 @ 115200) None
Response (AT #2 @ 115200) None
The current delay is 4000
Response (+++ #1): None
Response (AT #1) None
Response (AT #3) None
Response (AT #4) None
Response (AT #1 @ 115200) None
Response (AT #2 @ 115200) None
The current delay is 5000
Response (+++ #1): None
Response (AT #1) None
Response (AT #3) None
Response (AT #4) None
Response (AT #1 @ 115200) None
Response (AT #2 @ 115200) None
Modem state: None
Could not detect your modem!
Please try to power off your device and restart in safeboot mode.
Success1? True
Success2? True
mirror? False  recover? False  resume? False  direct? False  atneg_only? False bootrom? False load_fff? False
baudrate: 921600 target_baudrate: 921600
Initial prepartion complete...
Loading /sd/CATM1-5.2-48829-1.dup
Attempting AT wakeup... [921600]
b''
count=1
b''
count=2
b''
count=3
b''
count=4
b''
count=5
b''
count=6
b''
count=7
b''
count=8
b''
count=9
b''
count=10
b''
True
>>>```


What do I do to get my modem back? 
I am looking forward to finding a resolution.
Please, lets not have this be another unresolved thread.

Jeff

[Gijs]

Please follow the suggestions I mention in this recent thread: https://forum.pycom.io/topic/6909/couldn-t-connect-to-modem-modem_state-disconnected/ (If theyre not mentioned in other threads already)

As a last resort, you can contact me at support@pycom.io for the manual UART reading

[Jeff Brown]

@Gijs Thanks for your response, but I'm not sure I completely understand. I tried all of that. Since the modem is in an unconnected state the only response I ever get from the modem is "NONE", including the serial test and the best response I have gotten from the GPy itself is something like: "OSError: Couldn't connect to Modem!" OR "Modem State Unknown) (Paraphrasing if I didn't get it exact")

Here's my serial test:

>>> from machine import UART
>>> import time
>>> # Open serial connection to LTE modem
>>> serial = UART(1, baudrate=921600, pins=('P20', 'P18', 'P19', 'P17'), timeout_chars=1)
>>> # For example write AT to modem
>>> serial.write("AT" + '\r\n')
4
>>> # Read back the response from the modem
>>> time.sleep(3)
>>> print(serial.read())       
None
>>>  # Deinit uart to lte modem
>>> serial.deinit()
>>>

Am I supposed to try different Baud rates as well?

Power cycling doesn't work, I have tried dozens of times
I can't crate an lte as the modem is in a disconnected state,

Beside manual uart procedure, did I miss something?

I have only used power from the same source, plugged into my laptop and it has worked dozens of times (with both antennae connected), so I don't think it can be a power issue. (power certainly did not fluctuate during use as the Laptop is always plugged in and at full charge)

What's next?

Jeff

[Gijs]

You can try different baudrates, as there is the possibility the modem is communicating on a different speed. Though I'll respond to your support request to figure this out in more detail!