RE: What are the prerequisites to get the ICCID

dejans — Wed, 19 Mar 2025 16:33:27 GMT

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.

[quote user="lseg"]I'm not sure if this is the proper way of doing it, but it seems to work[/quote]

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

[quote user="lseg"]Not sure if I should set function mode back to off before starting connection.[/quote]

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

Best regards,
Dejan

RE: What are the prerequisites to get the ICCID

lseg — Wed, 19 Mar 2025 15:31:32 GMT

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.