Simple Modem on/off test

[Randall]

I'm working on an application where I will need to initialize the modem, send/receive messages and then turn it down to low power until the next checkin.  I did a real simple loop in a thread that turned on and off the modem and it always ends up locking up in the reinitialization or power down of the modem.  I've tried several variants based on examples I've seen on the forum but nothing seems to work.  Right now I create a new thread and have a loop like this;

while( true )
{
err = k_msgq_get(&mm_msg_que, &recvEvent, K_SECONDS(CHECK_IN_TIMER_INTERVAL_SECONDS));
if ( (err == -EAGAIN) || (err == 0) )
{
printk( "Initializing Modem\n" );
if ( (err = lte_lc_init_and_connect() ) )
{
printk( "Unable to connect to Modem\n" );
k_sleep(5000);
continue;
}
lte_lc_psm_req(true);
printk( "Sending Check In Message\n" );

printk( "Pretending to connect to Cloud\n" );
k_sleep(5000);
dk_set_led_on(2);
k_sleep(5000);
dk_set_led_off(2);

lte_lc_psm_req(false);
printk( "Turning off Modem\n" );
if ( (err = lte_lc_offline() ) )
{
printk( "Failure turning off Modem: %d\n", err );
}
}
k_sleep(1000);
}

Is this the improper way to do it.  I'm thinking that it must be locking up on the blocking send().  This seems like such a simple task, I'm not sure what I'm missing.

[Randall]

I'm not sending any data.  That is the point.  I'm enabling the modem, waiting 10 seconds, then disabling the modem. The CHECK_IN_INTERVAL is another 10 seconds so it isn't connecting every second.  I'm just using this as a cycle test to experiment with turning on and off the modem.  It will be difficult to send the whole project.  This is part of a separate thread that is managing modem communications.  I also have another thread that I'm working on that is handling communications with peripherals.  

[Sigurd]

I have not been able to reproduce this lockup. Here is the code I used to test this:

main.c

/*
 * Copyright (c) 2018 Nordic Semiconductor ASA
 *
 * SPDX-License-Identifier: LicenseRef-BSD-5-Clause-Nordic
 */

#include <zephyr.h>
#include <stdio.h>
#include <uart.h>
#include <string.h>

#include <lte_lc.h>
#include <dk_buttons_and_leds.h>


/**@brief Recoverable BSD library error. */
void bsd_recoverable_error_handler(uint32_t err)
{
	printk("bsdlib recoverable error: %u\n", err);
}

/**@brief Irrecoverable BSD library error. */
void bsd_irrecoverable_error_handler(uint32_t err)
{
	printk("bsdlib irrecoverable error: %u\n", err);

	__ASSERT_NO_MSG(false);
}

void main(void)
{
	printk("The test sample started\n");
	
	bool testing = true;
	
	int err = 0;
	
	while(testing){
			
	printk( "Initializing Modem\n" );
	printk("LTE Link Connecting ...\n");
	
	err = lte_lc_init_and_connect();
	
	if(err == 0)
	{
		printk("LTE Link Connected!\n");
	}
	else{
		printk("LTE link could not be established.\n");
	}
	
	
	lte_lc_psm_req(true);
	
	printk( "Pretending to connect to Cloud\n" );
	k_sleep(5000);
	//dk_set_led_on(2);
	k_sleep(5000);
	//dk_set_led_off(2);
	
	lte_lc_psm_req(false);
	
	printk( "Turning off Modem\n" );
	
	if ( (err = lte_lc_offline() ) )
	{
	printk( "Failure turning off Modem: %d\n", err );
	}
	else{
		printk("Modem turned off\n");
	}
	
	k_sleep(1000);
	
    }

}

prj.conf

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

# Network
CONFIG_NETWORKING=y
CONFIG_NET_SOCKETS=y
CONFIG_NET_SOCKETS_OFFLOAD=y

CONFIG_LOG=y
CONFIG_LOG_IMMEDIATE=y
#CONFIG_AT_CMD_LOG_LEVEL_DBG=y
#CONFIG_LOG_DEFAULT_LEVEL=3
#CONFIG_LOG_OVERRIDE_LEVEL=3
CONFIG_DEBUG=y


# BSD library
CONFIG_BSD_LIBRARY=y

# AT host library
CONFIG_AT_HOST_LIBRARY=y
CONFIG_UART_INTERRUPT_DRIVEN=y

# Stacks and heaps
CONFIG_MAIN_STACK_SIZE=2048
CONFIG_HEAP_MEM_POOL_SIZE=16384

# Disable native network stack to save some memory
CONFIG_NET_IPV4=n
CONFIG_NET_IPV6=n
CONFIG_NET_UDP=n
CONFIG_NET_TCP=n

# LTE link control
CONFIG_LTE_LINK_CONTROL=y
CONFIG_LTE_AUTO_INIT_AND_CONNECT=n

# Library for buttons and LEDs
CONFIG_DK_LIBRARY=y
CONFIG_DK_LIBRARY_INVERT_LEDS=n

I used this command to build and flash the sample: 

nrfjprog -e && west build -b nrf9160_pca10090ns -d build -p && west flash -d build

PS: Modem firmware v1.0.1 was released this week. If you haven't already updated, I recommend to update. You can download the latest modem version from this page. This blog post here is for v1.0.0, but the end of the blog post shows you how to update the modem firmware using the programmer app in nRF Connect for desktop.

[Randall]

How long did you run it?  It takes several loops before it locks up, but usually within a day.  

I am still running modem firmware v1.0.0, I will upgrade and start running a new round of tests.

Thanks

[Randall]

Even with Modem Firmware 1.0.1 it still locks up.  It goes into lte_lc_init_and_connect() after about 30 loops and doesn't come back.  It's doing the same thing you are doing, but in a different thread that is kicked off by the main function.  

[E3V3A]

Sound like a memory leak. Try to check the heap...