Pycom GPy fails to attach with Things Mobile SIM

snebot snebot

System info: os.uname()

(sysname='GPy', nodename='GPy', release='1.20.2.r4', version='v1.11-ffb0e1c on 2021-01-12', machine='GPy with ESP32', pybytes='1.6.1')

Modem firmware version sqnsupgrade.info():

<<< Welcome to the SQN3330 firmware updater [1.2.6] >>>
>>> GPy with firmware version 1.20.2.r4
Your modem is in application mode. Here is the current version:
UE5.2.0.3
LR5.2.1.0-48829
+CEREG: 80

I have been trying to attach a Pycom GPY to the network with a Things Mobile SIM card. The code that I am using is based on the tutorial found here.

My code:

from network import LTE
import time
import socket

# bands
# GPy supports: 3, 4, 12, 13, 20, 28

lte = LTE(debug=True)

print(lte.send_at_cmd('AT^RESET'))
print(lte.send_at_cmd('AT+CFUN=0'))
print(lte.send_at_cmd('AT!="clearscanconfig"'))
print(lte.send_at_cmd('AT!="RRC::addScanBand band=20"'))
print(lte.send_at_cmd('AT+CGDCONT=1,"IP","TM"'))
print(lte.send_at_cmd('AT+CFUN=1'))

#lte.attach(apn="TM", band=20)
print("imei: " + str(lte.imei()))
print("iccid: " + str(lte.iccid()))
print("attaching..",end='')

lte.init(debug=False)
rsrpq = None
fsm = None
while not lte.isattached():
    rsrpq2 = lte.send_at_cmd('AT+CESQ').strip()
    if rsrpq2 != rsrpq:
        rsrpq = rsrpq2
        print(time.time(), rsrpq)
    fsm2 = lte.send_at_cmd('AT!="fsm"').strip()
    if fsm != fsm2:
        fsm=fsm2
        print(time.time(), fsm)
    time.sleep(0.1)
print(time.time(), "attached")

When trying to attach the FSM log shows that RCC TOP FSM goes from SCANNING to SYNCING to CAMPING and finally CAMPED. This cycle runs endlessly.

One full cycle log:

416 SYSTEM FSM
==========
    +--------------------------+--------------------+
    |            FSM           |        STATE       |
    +--------------------------+--------------------+
    | RRC TOP FSM              |SCANNING            |
    | RRC SEARCH FSM           |WAIT_RSSI           |
    | RRC ACTIVE FSM           |NULL                |
    | PMM PLMN FSM             |NORM_WAITCELL       |
    | 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                |
    | LPP FSM                  |IDLE                |
    | HP MAIN FSM              |IDLE                |
    | HP USIM FSM              |READY               |
    | HP SMS MO FSM            |IDLE                |
    | HP SMS MT FSM            |IDLE                |
    | HP CAT FSM               |IDLE                |
    +--------------------------+--------------------+

OK
421 SYSTEM FSM
==========
    +--------------------------+--------------------+
    |            FSM           |        STATE       |
    +--------------------------+--------------------+
    | RRC TOP FSM              |SCANNING            |
    | RRC SEARCH FSM           |WAIT_CELL_ID        |
    | RRC ACTIVE FSM           |NULL                |
    | PMM PLMN FSM             |NORM_WAITCELL       |
    | 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                |
    | LPP FSM                  |IDLE                |
    | HP MAIN FSM              |IDLE                |
    | HP USIM FSM              |READY               |
    | HP SMS MO FSM            |IDLE                |
    | HP SMS MT FSM            |IDLE                |
    | HP CAT FSM               |IDLE                |
    +--------------------------+--------------------+

OK
433 SYSTEM FSM
==========
    +--------------------------+--------------------+
    |            FSM           |        STATE       |
    +--------------------------+--------------------+
    | RRC TOP FSM              |SYNCING             |
    | RRC SEARCH FSM           |WAIT_SYNC           |
    | RRC ACTIVE FSM           |NULL                |
    | PMM PLMN FSM             |NORM_WAITCELL       |
    | 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                |
    | LPP FSM                  |IDLE                |
    | HP MAIN FSM              |IDLE                |
    | HP USIM FSM              |READY               |
    | HP SMS MO FSM            |IDLE                |
    | HP SMS MT FSM            |IDLE                |
    | HP CAT FSM               |IDLE                |
    +--------------------------+--------------------+

OK
433 SYSTEM FSM
==========
    +--------------------------+--------------------+
    |            FSM           |        STATE       |
    +--------------------------+--------------------+
    | RRC TOP FSM              |CAMPING             |
    | RRC SEARCH FSM           |WAIT_SIB1           |
    | RRC ACTIVE FSM           |NULL                |
    | PMM PLMN FSM             |ANY_WAITCELL        |
    | 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                |
    | LPP FSM                  |IDLE                |
    | HP MAIN FSM              |IDLE                |
    | HP USIM FSM              |READY               |
    | HP SMS MO FSM            |IDLE                |
    | HP SMS MT FSM            |IDLE                |
    | HP CAT FSM               |IDLE                |
    +--------------------------+--------------------+

OK
434 +CESQ: 99,99,255,255,8,57

OK
434 SYSTEM FSM
==========
    +--------------------------+--------------------+
    |            FSM           |        STATE       |
    +--------------------------+--------------------+
    | RRC TOP FSM              |CAMPED              |
    | RRC SEARCH FSM           |CAMPED_ANY          |
    | RRC ACTIVE FSM           |IDLE                |
    | PMM PLMN FSM             |ANY_CAMPED          |
    | 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                |
    | LPP FSM                  |IDLE                |
    | HP MAIN FSM              |IDLE                |
    | HP USIM FSM              |READY               |
    | HP SMS MO FSM            |IDLE                |
    | HP SMS MT FSM            |IDLE                |
    | HP CAT FSM               |IDLE                |
    +--------------------------+--------------------+

I have also tried another SIM card from a different operator (and changed APN setting). With both SIM cards I tried using different bands with the same result.

I know that the first time attaching it might take a long while (Pycom guides say ~30m). But in some occasions it has been running for ~1h 30m with no luck.

Explore Pybytes | Official Documentation | Report a Firmware Bug/Issue | GitHub

Pycom GPy fails to attach with Things Mobile SIM

Pycom on Twitter