What are the prerequisites to get the ICCID

[lseg]

Hi,

I would like to know what are the prerequisites to get the ICCID of the sim card:

    int err = 0;

    LOG_INF("Initializing modem library");
    /* initialize the modem library */
    err = nrf_modem_lib_init(NORMAL_MODE);
    if (err)
    {
        LOG_ERR("nrf_modem_lib_init error: %i", err);
    }

    /* register callbacks */
    lte_lc_register_handler(on_modem_lte_lc_event);

    err = nrf_modem_at_printf("AT%%CESQ=1");
    if (err)
    {
        LOG_ERR("nrf_modem_at_printf(CESQ): %i", err);
        return;
    }

    /* initialize info structures, this will contain the SIM card numbers as well */
    err = modem_info_init();
    if (err)
    {
        LOG_ERR("Failed to initialize modem info!");
        return;
    }

    LOG_INF("Changing functional mode");
    modem_get_info(INFO_IMEI); <=== in this internal function I can get the IMEI at this stage

    char temp_char[24] = {0};
    err = nrf_modem_at_cmd(temp_char, sizeof(temp_char), "AT%%XICCID");
    if(err == 0)
    {
        LOG_INF("AT cmd ICCID:    %s", temp_char);
    }
    else
    {
        LOG_ERR("AT cmd ICCID failed %d", err); <=== I always get here with error 65536
    }

This is the code I use, nothing special. I can get the IMEI of the modem but not the ICCID, I always get error 65536 which does not really make sense to me (= 0x10000, which is also not a negative nr).

Question is what do I need more to get the ICCID?
At this moment I do a lte_lc_init_and_connect, but that feels like overkill, just to get the ICCID...

Kind regards

[lseg]

I noticed here  Incorrect ICCID value from modem_infothat they are talking about CFUN 41 (Sim card only)

So I did this change:

    // Set the modem to activate only the UICC (SIM card)
    err = lte_lc_func_mode_set(LTE_LC_FUNC_MODE_ACTIVATE_UICC);
    if (err) {
        LOG_ERR("Failed to activate UICC, error: %d", err);
        return;
    }
    /* initialize info structures, this will contain the SIM card numbers as well */
    err = modem_info_init();
    if (err)
    {
        LOG_ERR("Failed to initialize modem info!");
        return;
    }
    // Retrieve the ICCID
    char iccid[24] = {0};
    err = modem_info_string_get(MODEM_INFO_ICCID, iccid, sizeof(iccid));
    if (err < 0) {
        LOG_ERR("Failed to get ICCID, error: %d", err);
    } else {
        LOG_INF("ICCID: %s", iccid);
    }

before modem_info_init i set lte_lc_func_mode_set(LTE_LC_FUNC_MODE_ACTIVATE_UICC) and after modem_info_init I readout the ICCID:​modem_info_string_get(MODEM_INFO_ICCID, iccid, sizeof(iccid))

And this seems to work.

I'm not sure if this is the proper way of doing it, but it seems to work... Not sure if I should set function mode back to off before starting connection.

[dejans]

Hi,

SIM card needs to be activated to be able to read UICCID. You can look at CFUN set command and lte_lc_func_mode API.
"Full functionality" corresponds to LTE_LC_FUNC_MODE_NORMAL, "Activates LTE without changing GNSS" (CFUN=21) corresponds to LTE_LC_FUNC_MODE_ACTIVATE_LTE and "Activates UICC" corresponds to LTE_LC_FUNC_MODE_ACTIVATE_UICC. All these 3 modes can accomplish UICC initialization.

lseg said:

I'm not sure if this is the proper way of doing it, but it seems to work

This is good news. Your method seems to be OK.

lseg said:

Not sure if I should set function mode back to off before starting connection.

When you use nrf_modem_lib_init(), it initializes the Modem library in normal operating mode.

Best regards,
Dejan