Error starting modem connection

[Massimo Rebellato]

I am trying to connect to vodafone network using the example found in "Tutorials & Examples > Networks > LTE"

I have connected the gpy module to the pc as shown in "Getting Started > Getting Started Programming the modules > USB Serial"

When I try to run the example code, I get the following error: "OSError: Couldn't start connection to Modem (modem_state=disconnected)"

After many retries, sometimes, the example starts without errors but goes in an infinite loop:

+SYSSTART

.
SYSTEM FSM

+--------------------------+--------------------+
|            FSM           |        STATE       |
+--------------------------+--------------------+
| RRC TOP FSM              |STOPPED             |
| RRC SEARCH FSM           |NULL                |
| RRC ACTIVE FSM           |NULL                |
| PMM PLMN FSM             |NULL                |
| EMM MAIN FSM             |NULL                |
| EMM AUTH FSM             |NULL                |
| EMM CONN FSM             |NULL                |
| EMM TAU FSM              |NULL                |
| EMM TEST FSM             |NULL                |
| ESM BEARER FSM           |BEARER_NULL         |
| SMS MT FSM               |IDLE                |
| SMS MO FSM               |IDLE                |
| HP MAIN FSM              |IDLE                |
| HP USIM FSM              |NULL                |
| HP SMS MO FSM            |IDLE                |
| HP SMS MT FSM            |IDLE                |
| HP CAT FSM               |NULL                |
+--------------------------+--------------------+

OK

.
+SYSSTART

.
SYSTEM FSM

+--------------------------+--------------------+
|            FSM           |        STATE       |
+--------------------------+--------------------+

Thanks for any help.

[Gijs]

Hi,
Could you let me know of the output with lte =LTE(debug=True), that way, we can verify the AT commands. Also be sure to verify the power supply capabilities, as the LTE modem might consume more current than expected
Could you also let me know of the following output:

import sqnsupgrade
sqnsupgrade.info(debug=True)

This will return a coredump at the end, please do not copy that over, but only the text at the top.
Let me know,
Gijs

[Jeroen Trappers]

@Gijs said in Error starting modem connection:

sqnsupgrade.info(debug=True)

I have the same issue.

Connecting to /dev/ttyACM0...
WMAC: 840D8E116C98
Firmware: 1.20.2.r4
Pybytes: 1.6.1
Initialized watchdog for WiFi and LTE connection with timeout 1260000 ms
WiFi connection established
Connected to MQTT mqtt.pybytes.pycom.io
Pybytes connected successfully (using the built-in pybytes library)
Pybytes configuration read from /flash/pybytes_config.json
Pycom MicroPython 1.20.2.r4 [v1.11-ffb0e1c] on 2021-01-12; GPy with ESP32
Pybytes Version: 1.6.1
Type "help()" for more information.
>>> 
>>> 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] >>>
>>> GPy with firmware version 1.20.2.r4
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
Cannot determine modem state!

[Gijs]

@Jeroen-Trappers Sorry for my late reply.
Could you try to power cycle the modem and see if that results in any progress?
If not, can you update the modem over UART using the instructions here: https://docs.pycom.io/updatefirmware/ltemodem/

Let me know!