u-blox LTE-M/NB-IoT Modems (SARA-R4xx, SARA-N4xx, but NOT SARA-N2xx)

[tcpipchip]

One question

To use this lib to access LTE-M/NB-IoT using SARA-R4/SARA-N4 needs some special initialization before to have access to the network ?

Some different AT COMMAND that those used to LISA ?

For example, LISA didnt need any special initialization! Works fine fist time!

Thank you!!!

[Mr-HaleYa]

mythical issue #420 🙏 🌿 🤘

[SRGDamia1]

There should not be any special set-up needed for the SARA R4 before using this library. In my experience, the LTE-M modules do take a long time to connect for the first time in a new location or with a new SIM so you may need to increase the length of the wait in the waitForNetwork function.

[tcpipchip]

Hi, @SRGDamia1

Well, it wont work until you do some first initializations before to use the TinyGSM lib, my opnion.

Do TinyGSM does not implement this sequence (AT COMMANDS)? (BOLD)

at+cfun=4

4: disables both transmit and receive RF circuits by deactivating both CS and PS services and sets the MT into airplane mode

at+umnoprof=100

Mobile Network Operator (MNO) configuration

at+cfun=15

To reset the module

at

OK

at+cedrxs=0

use of eDRX disabled

at+cedrxs=3,2

disable the use of eDRX and reset all parameters for eDRX to factoryprogrammed values

at+cedrxs=3,4

4: E-UTRAN (WB-S1 mode)

at+cedrxs=3,5

5: E-UTRAN (NB-S1 mode)

at+cpsms=0

disable the use of PSM

at+upsv=0

0 (default and factory-programmed value): power saving disabled

at+urat=7

Indicates the radio access technology and may be:

LTE CAT-M1

at+ubandmask=0,134217732

VIVO ?

at+ubandmask=1,134217732

VIVO ?

at+cfun=15

To reset the module

at+cfun=4

4: disables both transmit and receive RF circuits by deactivating both CS and PS services and sets the MT into airplane mode

at+cgdcont=1,"IPV4V6","smart.m2m.vivo.com.br" <- se você recebeu um APN diferente, altere a seção destacada para o valor correto

Defines the connection parameters for a PDP context

at+cgdcont?

Check current APN

at+umnoprof?

Check selected MNO Profile

at+cedrxs?

The following command example reads the requested eDRX value

at+cfun=1

Turn on the radio

at+cmee=2

I guess that they must to exist an void Your_Init_operator() { } function that should be called first, and then call at+cgdcont

Am i an right ?

[SRGDamia1]

In general, this library does not attempt to customize anything for a particular network operator or SIM card provider for any of the modules. That is completely left up to the user. If your operator requires you to manually set bands and disable PSM or EDRx, that is annoying, but that is not a universal problem.

I can't say I've ever used the PSM/EDRx commands and see no particular reason they'd be necessary unless it's something your SIM provider specifies.

Depending on your SIM card, you may not need to specify the operator profile. The "SW default" (0) or "SIM ICCID Select" (1) profiles might be just fine. I believe the commands for setting the band mask are only necessary if you are using the "Standard Europe" (100) operator profile. We use AT&T for the Hologram network in the USA and don't set the band. For while we didn't bother to set the operator at all, but we found it connected faster when manually selected.

I also would use AT+CFUN=0 rather than 4 to turn off the radios between switching bands or operators. The airplane mode set with AT+CFUN=4 will persist between resets, 0 will not. (That is, if you set to 0, then reset, the module will return to full functionality (1) after reset. If you set to 4 and then reset, you have to remember to manually set back to 1 afterwards.)

[tcpipchip]

Thank so much the info @SRGDamia1

In wich point of source do you suggest to make a call to a specialized AT commands before the make the final attach ?

[SRGDamia1]

If you need to set the bands, I'd do it right at the top of you program. If you're following the flow of most of the examples, you'd put it right after the modem.restart(); or modem.init().

You can use the sendAT and waitResponse library functions to send your custom commands, ie:

modem.sendAT(GF("+ubandmask=0,134217732"));
modem.waitResponse();

[tcpipchip]

@SRGDamia1

Thank you so much! You help me and will help a lot of other members!