Telstra LTE Cat-M Working on FiPy .... Just..

[nathanh]

@marcobenini said in Telstra LTE Cat-M Working on FiPy .... Just..:

@nathanh COPS comamnds are used for operator selection. Usually the mode is set to 0, so the selection is done automatically.
The command AT+COPS=? that You use does a scan of the network to get a list of available network operators.

Yea, so that is what I thought and I have no idea why it "helps". Trying to connect without calling it fails everytime, but for some reason when I do call it (noting it is not doing anything but reporting and COPS is set as 0 (automatic) by default, it seems to help with the process. Maybe it is forcing the modem to scan more thoroughly than setting CFUN to 1 ? Again this is all pure guess work.

It would be interesting to look at which LTE Cat M1 module is used.
With commands AT+CGMI , AT+CGMM , AT+CGMR You could get manufacturer, model and firmware version. Than one can search the manual with full list of supported commands.

Well it is documented by Pycom to be a Sequans modem with a link to the reference manual. I have been trying to go through it along with the firmware to try and understand what is happening but still struggling to take it all in. For what it is worth, here is the feedback from those commands you mentioned.

>>> send_atcmd('AT+CGMI')
SEQUANS Communications
OK
>>> send_atcmd('AT+CGMM')
VZM20Q
OK
>>> send_atcmd('AT+CGMR')
UEUnknown
OK

@nick_aus said in Telstra LTE Cat-M Working on FiPy .... Just..:

@nathanh did you get any further with your issues? Were you able to hold the connection open?

I am still finding it very unreliable, even trying to get the connection up in the first place. @IOAg found that if you call disconnect after sending a payload it does keep the modem from crashing for a time, which I have confirmed. But even using disconnect after every payload send I find after a while the modem completely crashes and even a reset does not help.

After looking at the Pycom firmware, the only difference I see between what I am doing and the attach/connect commands alone is first I set the APN and second I use the AT+COPS command to show the networks, yet for some reason it seems to help.

I also am starting to suspect that the antenna I purchased (which is labeled as the FiPy/Gpy antenna) is not tuned for Band 28. I cannot seem to find any real documentation or details on it. I was going to try and put it onto a wave generator and specan next week to make sure it is tuned to the correct frequencies. For reference here are some pictures of it.

[MarcoBenini]

@nathanh COPS comamnds are used for operator selection. Usually the mode is set to 0, so the selection is done automatically.
The command AT+COPS=? that You use does a scan of the network to get a list of available network operators. If You parse the response You'll see the network operators found by the modem.
It takes several time and also, if the modem was registered or started to registration process, that is stopped.

It would be interesting to look at which LTE Cat M1 module is used.
With commands AT+CGMI , AT+CGMM , AT+CGMR You could get manufacturer, model and firmware version. Than one can search the manual with full list of supported commands.

[nick_aus]

@nathanh did you get any further with your issues? Were you able to hold the connection open?

[IOAg]

Thank @nathanh for your detailed explanation, so glad somebody got it working. I had been struggling for 2 days because I was using Wifi to connect to device, when I switched to COM it made it work by magic.

@daniel Is it expected pycom/Wifi use causes LTE-M to stop working?

Been using:
(sysname='FiPy', nodename='FiPy', release='1.17.0.b1', version='v1.8.6-849-d0dc708 on 2018-02-27', machine='FiPy with ESP32', lorawan='1.0.2', sigfox='1.0.1')

Last point, connection drops for me as well after a short while; if i call disconnect(), I can reconnect readily.

[nathanh]

@daniel Hi Daniel, happy to help anyway I can, I sent you a private message.

[daniel]

@nathanh thanks for this post! Would you be willing to get on a TeamViewer session with me so that I can see what is causing the modem to hang after connecting? Thanks again!

Cheers,
Daniel