BORON 2G/3G External sim

[Energy]

Hello,

I have boron 2G/3G kit i want use external sim with it in INDIA.
I already use BSNL sim before with it, but now in INDIA there is no particular 2G/3G sim available all are in 4G and 5G (BSNL,Airtel,VI..)

so, is there any possibility to use 4G sim with my 2G/3G boron kit?

@rickkas7

[rickkas7]

It's not a SIM limitation. It's that the cellular modem on the Boron 2G/3G does not support LTE. It's not possible use the Boron 2G/3G in locations that do not have 2G or 3G service.

The only options at this time are the B-SoM B524 and M-SoM M524, however these devices do not support an external SIM and there are permanent roaming restrictions in India and are not recommended.

[Energy]

I guess there has been a misunderstanding.
There is 2G/3G coverage in INDIA region. And I`m using Boron 2G/3G kit (pre-2021). According to the Docs, I should be able to use an external SIM Card. I was able to test it with a BSNL (3G) SIM Card, but i seem to have misplaced it somewhere. So, just to resolve a doubt, can i use my LTE SIM in the boron to utilize 2G/3G?

[rickkas7]

Yes, that should work, as long as your LTE 3rd-party SIM is from a carrier that still supports 2G/3G.

[Energy]

we tried following the documentation for configuring boron with 3rd party external SIM. We flashed this code to the boron.

#include "Particle.h"

#include "dct.h"

SYSTEM_MODE(SEMI_AUTOMATIC);

void setup() {
    Cellular.setActiveSim(EXTERNAL_SIM);
    Cellular.setCredentials("www"); // Replace with the correct APN

    // This clears the setup done flag on brand new devices so it won't stay in listening mode
    const uint8_t val = 0x01;
    dct_write_app_data(&val, DCT_SETUP_DONE_OFFSET, 1);

    // This is just so you know the operation is complete
    pinMode(D7, OUTPUT);
    digitalWrite(D7, HIGH);
}

void loop() {
}

And then we flashed tinker to boron.
Now, the boron is stuck in a reset loop (blinking green, then it resets). We can see the ICCID of our SIM Card via particle identify.
Are we missing out any steps?

[rickkas7]

How did you flash the device? The recommended way is to use Workbench and use Particle: Flash application (local).

If you used another method like the CLI, make sure you target the version of Device OS that is already on the device, or flash that version of Device OS first.

If that code caused the device to go into blinking green, it's because the target version of the firmware you compiled is higher than what is on the device and it's trying to go online to get the updated Device OS binaries, but it can't do so, because the SIM or APN setting is wrong.

[Energy]

We used CLI to flash the device. we made sure that the OS version is consistent. But we are still facing those issues. There seems to be no issues with the SIM Card itself.
P.S.: We used this documentation. https://docs.particle.io/troubleshooting/guides/connectivity-troubleshooting/using-3rd-party-sim-cards/

[rickkas7]

Sorry, I just noticed that you flashed tinker again, and it was blinking green for tinker, not for the APN setting code.

The next step is to use Web Device Doctor or Cloud Debug to get a log of what the device is doing and make sure the SIM change took effect.

Since it's stuck at blinking green, the problem is that the SIM switch did not occur, the SIM is not activated with the 3rd-party platform, or there is no coverage at that location for that SIM for 2G/3G. The log should indicate which.

If the device was stuck at blinking cyan it could be the APN.

[Energy]

We are not able to get the logs as the device keeps on disconnecting. Using particle identify, we observed that the SIM switch did occur. As for network coverage, we referenced this documentation https://docs.particle.io/reference/cellular/cellular-carriers/?tab=ByDevice&device=Boron%20BRN310%202G%2F3G%20Global%20(before%202021)&region=Asia
It mentions that the India Region has two Carriers - Vi & Airtel. We are using the Vi SIM Card.

[rickkas7]

Disconnecting from USB? During flash, or when trying to obtain the log?

Do you have the external LiPo battery connected? That is required for 2G/3G, and can also prevent being able to connect if not connected.

[Energy]

Got It !! It seems that I neglected the need of the battery. After making the connection, it works as intended. Thank you for being patient with us. And sorry for taking up too much of your time.
Again, Thank you very much.