How to use socket?

[Yusuke]

<Environment>
- Windows10
- nrf v1.3.0
- modem fw 1.2.0

I'm attempting to make a socket and communicate with the modem using it.

However, sending data doesn't work out. It was working in v1.2.0. Any tip?

I don't want to use at_cmd.c becuase I need a exclusive  socket for SMS notification.

<main.c>

#include <zephyr.h>
#include <stdio.h>
#include <net/socket.h>
#include <modem/lte_lc.h>

#define BUF_LEN 128

int fd;

void main(){
    int ret;
    char at_cmd[] = "AT\n";
    char buf[BUF_LEN];
    
	/* Configure LTE-M */
    printk("LTE Link Connecting ...\n");
    ret = lte_lc_init_and_connect();
    printk("LTE Link Connected!\n");
	if (ret) {
		printk("Error: modem_configure\n");
		return;
	}

	/* SMS socket set up*/
	fd = socket(AF_LTE, 0, NPROTO_AT); /* init fd */
	if (fd == -1) {
		return;
	}

	// Send AT command => ERROR !!
	if (send(fd, at_cmd, strlen(at_cmd), 0) <= 0) {
        printk("Error: send\n");
        return;
    }

	// blocking receive
	if (recv(fd, buf, BUF_LEN, MSG_DONTWAIT) <= 0) {
        printk("Error: send\n");
        return;
    }

    printk("Socket works out!\n");
    
    return;
}

[Martin Lesund]

Hi Yusuke,

In NCS v1.3.0 we actually have an "SMS subscriber" library which you could use to accomplish this.
if you instead want to use regular AT commands, you make sockets the following way.

[Yusuke]

Can't receive SMS by this program. Any tip?

<prj.conf>

#
# Copyright (c) 2019 Nordic Semiconductor ASA
#
# SPDX-License-Identifier: LicenseRef-BSD-5-Clause-Nordic
#
# General config
CONFIG_ASSERT=y

# Network
CONFIG_NETWORKING=y
CONFIG_NET_NATIVE=n
CONFIG_NET_SOCKETS=y
CONFIG_NET_SOCKETS_OFFLOAD=y

# SMS
CONFIG_SMS=y

# LTE link control
CONFIG_LTE_LINK_CONTROL=y
CONFIG_LTE_LOCK_BANDS=y
CONFIG_LTE_LOCK_BAND_MASK="10000000"
CONFIG_LTE_NETWORK_MODE_LTE_M=y
CONFIG_LTE_AUTO_INIT_AND_CONNECT=n

# BSD library
CONFIG_BSD_LIBRARY=y

# AT host library
CONFIG_AT_HOST_LIBRARY=n
CONFIG_UART_INTERRUPT_DRIVEN=y

# Stacks and heaps
CONFIG_MAIN_STACK_SIZE=3072
CONFIG_HEAP_MEM_POOL_SIZE=16384

# SEGGER RTT for Dev
CONFIG_PRINTK=y
CONFIG_CONSOLE=y
CONFIG_STDOUT_CONSOLE=y
CONFIG_UART_CONSOLE=n
CONFIG_RTT_CONSOLE=y
CONFIG_USE_SEGGER_RTT=y

<main.c>

#include <zephyr.h>
#include <stdio.h>
#include <modem/sms.h>
#include <modem/lte_lc.h>

void sms_handler(struct sms_data *const data, void *context)
{
    printk("here\n");
}

void main(){
    int ret;
    
	/* Configure LTE-M */
    printk("LTE Link Connecting ...\n");
    ret = lte_lc_init_and_connect();
    printk("LTE Link Connected!\n");
	if (ret) {
		printk("Error: modem_configure\n");
		return;
	}

	/* SMS socket set up */
	if (sms_init() != 0) {
        printk("ERROR: sms_init\n");
		return;
	}

    /* Set up listener */
	if (sms_register_listener(sms_handler, NULL) != 0) {
        printk("ERROR: sms_register_listener\n");
		return;
	}

    printk("SMS waiting...");
    
    while(1){}
}