I´m trying to Attach and Connect to LTE network using the following code:
https://core-electronics.com.au/tutorials/pycom-gpy-getting-started.html
(tutorial from core-electronics)

The problem is this lines down:

print("Configuring LTE ", end='')
lte.send_at_cmd('AT+CGDCONT=1,"IP","telstra.internet"')
print(".", end='')
lte.send_at_cmd('AT!="RRC::addscanfreq band=28 dl-earfcn=9410"')
print(".", end='')
lte.send_at_cmd('AT+CFUN=1')
print(" OK")

I understand that the telstra.internet refeers to the Nano SIM Card. I used to use an moden for my Raspberry pi 3b and used to send this AT-commands:

• ATZ
• ATQ0 V1 E1 S0=0 &C1 $D2 +FCLASS=0
• AT+CGDCONT=1,"IP","zap.vivo.com.br"
• AT+CFUN =1,0

And didn´t work.

Vivo refeers to my Nano SIM Card, but i really dont know much about the AT-commands in a moldem.

By the way, i have updated the firmware from my Gpy, the board to the Pymakr and the modem with internal commands in Atom.

Has anyone has an idea to help me?

Is the sim current?

What response do you get to mood=lte.send_at_cmd('at+cpin?').split('\r\n')[1]; print('modem', mood)

lte.send_at_cmd('AT^RESET')

attachment only works if the mood is 'ready' or 'sysstart'

mood=lte.send_at_cmd('at+cpin?').split('\r\n')[1]
print('modem', mood)
simreg=lte.send_at_cmd('at+creg?').split(',')[1][:1]
print('sim reg =', simreg, end=' ')
service=lte.send_at_cmd('AT+cind?').split(': ')[1][2]
print('service =', service)
time.sleep(1)

and this was the answer:

modem +CPIN: READY
sim reg = 0 service = 0

Sorry for my ignorance, but I really don't know much about it.
Do you know something?

print("Resetting LTE modem ... ", end='')
lte.send_at_cmd('AT^RESET')
print("OK")
time.sleep(2)

and you´re right. I move this commands to my 'attach loop' see:

#Code
print("Configuring LTE ", end='')
lte.send_at_cmd('AT+CGDCONT=1,"IP","zap.vivo.com.br"')
print(".", end='')
lte.send_at_cmd('AT!="RRC::addscanfreq band=28 dl-earfcn=9410"')
print(".", end='')
lte.send_at_cmd('AT+CFUN=1')
print(" OK")
time.sleep(1)

mood=lte.send_at_cmd('at+cpin?').split('\r\n')[1]; print('modem', mood)


# If correctly configured for carrier network, attach() should succeed.
if not lte.isattached():
    print("Attaching to LTE network ", end='')
    lte.attach()
    while(True):
        if lte.isattached():
            print(" OK")
            break
        print('.', end='')
        simreg=lte.send_at_cmd('at+creg?').split(',')[1][:1]; print('sim reg =', simreg, end=' ')
        service=lte.send_at_cmd('AT+cind?').split(': ')[1][2]; print('service =', service)
        time.sleep(1)

and the return now is:
sim reg = 2 service = 0

I think the error is in
lte.send_at_cmd('AT!="RRC::addscanfreq band=28 dl-earfcn=9410"')

Do you know something to help?

Hm, question: Is it ok to use a LoRa antenna to this Attaching? Or it´s realy required the LTE antenna? The frequency is the same

Hm, yeah thanks, that´s a good view.
Just one last question: if i get the LTE antenna, will i get more success results or change the antenna is not that important?

Also, you may need a specific subscription for this, it may not work with a regular LTE subscription (from what I understand at least NB-IoT will have specific billing structure).

Apparently Vivo uses LTE bands 3, 7 and 28. Don't restrict yourself to a single band, coverage at your place may be available in only some of those bands. The FiPy does not support band 7, though.

Also make sure you have recent firmware for both the modem and FiPy, and that the modem firmware you use matches the technology you want (Cat-M1 or NB-IoT).

Well... there are?

#code
import socket
import ssl
import time
from network import LTE
import pycom

pycom.heartbeat(False)

lte = LTE(carrier="verizon") # instantiate the LTE object
lte.attach(band=13) # attach the cellular modem to a base station, initially it was lte.attach()
print( " While loop1") # print stmt to check on terminal
time.sleep(5) # added 5 seconds wait
pycom.rgbled(0x0000ff) # BLUE LED

print(lte.send_at_cmd('ATZ'))
time.sleep(0.5)
print(lte.send_at_cmd('ATQ0'))
time.sleep(0.5)

print(lte.send_at_cmd('AT+CGDCONT=1,"IP","zap.vivo.com.br"'))
time.sleep(0.5)
print(lte.send_at_cmd('AT+CGAUTH=1,1,"vivo","vivo"'))
time.sleep(0.5)

lte.send_at_cmd('AT+CFUN=1')
time.sleep(1)

mood=lte.send_at_cmd('at+cpin?').split('\r\n')[1]; print('modem', mood)

while not lte.isattached():
print('Signal:%s'%lte.send_at_cmd('AT+CSQ'))
lte.send_at_cmd('AT+CSQ')
print('Status:%s '%lte.send_at_cmd('AT+CEER'))
lte.send_at_cmd('AT+CEER')
time.sleep(5) # originally 0.25 changed to 5.0
lte.attach()
lte.connect(cid=3) # start a data session and obtain an IP address
print( " While loop2")
pycom.rgbled(0x00ff00) # GREEN LED
while not lte.isconnected():
time.sleep(0.25)

s = socket.socket()
s = ssl.wrap_socket(s)
s.connect(socket.getaddrinfo('www.google.com', 443)[0][-1])
s.send(b"GET / HTTP/1.0\r\n\r\n")
print(s.recv(4096))
s.close()
#endcode

the message that i´m receiving is:

Signal:
+CSQ: 22,99

OK

Status:
+CEER: lastEmmCause: NO_SUITABLE_CELLS_IN_TRACKING_AREA, lastEsmCause: EMM_NOT_ATTACHED

Has any one has an idea of what that means? '-'