8.7 KiB
title, aliases
| title | aliases | |
|---|---|---|
| LTE Examples |
|
The following tutorial demonstrates the use of the LTE CAT-M1 and NB-IoT functionality on cellular enabled Pycom modules.
GPy and FiPy support both LTE CAT-M1 and NB-IoT. These are newer, low power, long range, cellular protocols. They are not the same as the full version of 2G/3G/LTE supported by cell phones, and require your local carriers to support them. At the time of writing, CAT-M1 and NB-IoT connectivity is not widely available so be sure to check with local carriers if support is available where you are. Together with the SIM card, the provider will supply you with configuration details: Usually band and APN. Use these in the example code below.
from network import LTE
import time
import socket
lte = LTE()
#when using verizon, use
#lte.init(carrier=verizon)
#when usint AT&T use,
#use lte.init(carrier=at&t)
#some carriers do not require an APN
#also, check the band settings, for some carriers they auto-configure.
lte.attach(band=20, apn="your apn")
while not lte.isattached()
time.delay(0.25)
print('.')
print(lte.send_at_cmd('AT!="fsm"')) # get the System FSM
print("LTE modem attached!")
lte.connect()
while not lte.isconnected():
time.sleep(0.25)
print('#')
#print(lte.send_at_cmd('AT!="showphy"'))
print(lte.send_at_cmd('AT!="fsm"'))
print("LTE modem connected!")
print(socket.getaddrinfo('pycom.io', 80))
lte.deinit()
#now we can safely machine.deepsleep()
The last line of the script should return a tuple containing the IP address of the Pycom webserver.
Note: the first time, it can take a long while to attach to the network.
LTE Troubleshooting guide
Below, we review the responses from print(lte.send_at_cmd('AT!="fsm"')). If you are having trouble attaching to the network, or getting a connection up and running, this might give some direction into what you are looking for. We are mainly looking at the status of the top two indicators for now.
-
Before calling
lte.attach(), the status will beSTOPPED.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 |READY | | HP SMS MO FSM |IDLE | | HP SMS MT FSM |IDLE | | HP CAT FSM |IDLE | +--------------------------+--------------------+ -
With no SIM card detected, the
RRC TOP FSMwill keep statusCAMPED. You will seeHP USIM FSMmarkedABSENT.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 | | HP MAIN FSM |IDLE | | HP USIM FSM |ABSENT | | HP SMS MO FSM |IDLE | | HP SMS MT FSM |IDLE | | HP CAT FSM |NULL | +--------------------------+--------------------+ -
SIM card inserted and attaching:
- While
SCANNING, theRRC SEARCH FSMgoes fromWAIT_RSSItoWAIT_CELL_ID - Later, the
RRC TOP FSMgoes fromSCANNINGtoSYNCING - There are some states in between not discussed here.
- If it is stuck at
WAIT_RSSI, check the antenna connection - If the system returns multiple times from
SYNCINGtoCAMPED, check the network availability, simcard placement and / or the firmware version.
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 | | HP MAIN FSM |IDLE | | HP USIM FSM |READY | | HP SMS MO FSM |IDLE | | HP SMS MT FSM |IDLE | | HP CAT FSM |IDLE | +--------------------------+--------------------+ - While
-
Connecting
SYSTEM FSM ========== +--------------------------+--------------------+ | FSM | STATE | +--------------------------+--------------------+ | RRC TOP FSM |CONNECTING | | RRC SEARCH FSM |CAMPED | | RRC ACTIVE FSM |WAIT_SMC | | PMM PLMN FSM |NORM_CAMPED | | EMM MAIN FSM |REGISTERED_INIT | | EMM AUTH FSM |WAITING_SIM_CONFIRM | | EMM CONN FSM |AS_ESTABLISHED | | EMM TAU FSM |NULL | | EMM TEST FSM |NULL | | ESM BEARER FSM |BEARER_NULL_PENDING_ACTIVE| | SMS MT FSM |IDLE | | SMS MO FSM |IDLE | | HP MAIN FSM |IDLE | | HP USIM FSM |READY | | HP SMS MO FSM |IDLE | | HP SMS MT FSM |IDLE | | HP CAT FSM |IDLE | +--------------------------+--------------------+ -
Connected
SYSTEM FSM ========== +--------------------------+--------------------+ | FSM | STATE | +--------------------------+--------------------+ | RRC TOP FSM |CONNECTED | | RRC SEARCH FSM |CAMPED | | RRC ACTIVE FSM |CONNECTED | | PMM PLMN FSM |NORM_CAMPED | | EMM MAIN FSM |REGISTERED | | EMM AUTH FSM |KASME_DEFINED | | EMM CONN FSM |AS_ESTABLISHED | | EMM TAU FSM |NULL | | EMM TEST FSM |NULL | | ESM BEARER FSM |BEARER_ACTIVE | | SMS MT FSM |IDLE | | SMS MO FSM |IDLE | | HP MAIN FSM |IDLE | | HP USIM FSM |READY | | HP SMS MO FSM |IDLE | | HP SMS MT FSM |IDLE | | HP CAT FSM |IDLE | +--------------------------+--------------------+
- Firmware version:
Use the following to check the version number:
import sqnsupgrade sqnsupgrade.info()- Versions LR5.xx are for CAT-M1
- Versions LR6.xx are for NB-IoT
- Potential other errors:
OSError: [Errno 202] EAI_FAIL: Check the data plan / SIM activation status on network