Enabling eDRX on mqtt_simple on nRF9160

[Mohammad Amin]

Hi,

I want to activate eDRX on mqtt_simple example and measure the current consumption. I guess based on the code, by enabling "CONFIG_LTE_EDRX_REQ" it will be activated. Is there anything else that I should do in order to reduce power consumption?

My other question is about measuring the current, I read in the current measurement instruction on this topic but I want to know if it is possible to use power profiler kit on nRF9160 to measure the power.

[Bjørn Kvaale]

Update: Woops, forgot to answer your first question  Just add the following code to the mqtt simple example (after the modem_configure() function is a good place):

        err = lte_lc_edrx_req(true);
        if (err) {
                printk("ERROR: set edrx %d\n", err);
                return;
        }

This function should be defined in lte_lc.c. You can then easily check to see that edrx is set by using the following AT command in LTE Link Monitor: 

AT+CEDRXS?

You can naturally also check to make sure that no error has been returned.

No, you cannot use the power profiler kit to measure the nRF9160 DK current consumption. If you have the v0.8.5 nRF91 DK, just follow the User Guide found here. If you have an older version of the nRF91 DK (i.e. <v0.8.5), take a look at this devzone case.

[Yusuke]

Hi, Bjørn

I want to set a keep alive value of MQTT while eDRX is enabled, but it doesn't work well. Could you give me any advice?

Environment
- hardware: nRF9160 DK 0.8.2
- firmware: 0.7.0-29.alpha
- nrf ver: 0.4.0
- LTE-M
- eDRX enable
- mqtt_simple works fine with mosquitto MQTT broker
- project based on mqtt_simple
- antenna power is fine
- eDRX service is available here

AT+CEDRXS?
OK
AT+CEDRXS=1,4,"1000"

I added MQTT_KEEPALIVE param to Kconfig and CONF_MQTT_KEEPALIVE param to pro.conf
I've tested several conditions
[condition]
- CONFIG_LTE_EDRX_REQ_VALUE="0110" in prj.conf // 327.68 sec interval
- CONF_MQTT_KEEPALIVE=300 in prj.conf
[result]
- eDRX doesn't work properly. When I send a message to a MQTT broker, the DK receives it right after that. There should be a delay due to the eDRX.

[condition]
- CONFIG_LTE_EDRX_REQ_VALUE="0110" in prj.conf // 327.68 sec interval
- CONF_MQTT_KEEPALIVE=300 in prj.conf
[result]
- The DK does not receive any message after 360sec followed by disconnection.

This is the whole project.

<Kconfig>
menu "MQTT simple sample"
config MQTT_PUB_TOPIC
	string "MQTT publish topic"
	default "my/publish/topic"

config MQTT_SUB_TOPIC
	string "MQTT subscribe topic"
	default "my/subscribe/topic"

config MQTT_CLIENT_ID
	string "MQTT Client ID"
	default "my-client-id"

config MQTT_BROKER_HOSTNAME
	string "MQTT broker hostname"
	default "iot.eclipse.org"

config MQTT_BROKER_PORT
	int "MQTT broker port"
	default 1883

config MQTT_MESSAGE_BUFFER_SIZE
	int ""
	default 128

config MQTT_PAYLOAD_BUFFER_SIZE
	int ""
	default 128

config MQTT_KEEPALIVE
	int ""
	default 60

endmenu

menu "Zephyr Kernel"
source "$ZEPHYR_BASE/Kconfig.zephyr"
endmenu

<prj.conf>

# General config
CONFIG_TEST_RANDOM_GENERATOR=y

# Networking
CONFIG_NETWORKING=y
CONFIG_NET_SOCKETS_OFFLOAD=y
CONFIG_NET_SOCKETS=y
CONFIG_NET_SOCKETS_POSIX_NAMES=y

# LTE link control
CONFIG_LTE_LINK_CONTROL=y
CONFIG_LTE_NETWORK_MODE_LTE_M=y
CONFIG_LTE_AUTO_INIT_AND_CONNECT=n
# CONFIG_LTE_EDRX_REQ_ACTT_TYPE="4"
CONFIG_LTE_EDRX_REQ=y
CONFIG_LTE_EDRX_REQ_VALUE="0110"
# 0100 81.92sec
# 0101 163.84sec
# 0110 327.68sec
# 0111 655.36sec

# LTE link control
CONFIG_LTE_LINK_CONTROL=y
CONFIG_LTE_AUTO_INIT_AND_CONNECT=n

# BSD library
CONFIG_BSD_LIBRARY=y

# AT Host
CONFIG_UART_INTERRUPT_DRIVEN=y
CONFIG_AT_HOST_LIBRARY=y

# MQTT
CONFIG_MQTT_LIB=y
CONFIG_MQTT_LIB_TLS=n

# Appliaction
CONFIG_MQTT_PUB_TOPIC="myPubTopic"
CONFIG_MQTT_SUB_TOPIC="mySubTopic"
CONFIG_MQTT_CLIENT_ID="myClientID"
CONFIG_MQTT_BROKER_HOSTNAME="xxxxxxxxxx.com"
CONFIG_MQTT_BROKER_PORT=1883
CONFIG_MQTT_KEEPALIVE=300 # ADD here

# Main thread
CONFIG_MAIN_THREAD_PRIORITY=7
CONFIG_MAIN_STACK_SIZE=4096

CONFIG_HEAP_MEM_POOL_SIZE=1024

<main.c>

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

#include <net/mqtt.h>
#include <net/socket.h>
#include <lte_lc.h>

#define MQTT_USERNAME "username"
#define MQTT_PASSWORD "password"
.
.
.

/**@brief Initialize the MQTT client structure
 */
static void client_init(struct mqtt_client *client)
{
	mqtt_client_init(client);

	broker_init();

    /* Add from here */
    static struct mqtt_utf8 password;
	static struct mqtt_utf8 user_name;

	password.utf8 = (u8_t *)MQTT_PASSWORD;
	password.size = strlen(MQTT_PASSWORD);
	user_name.utf8 = (u8_t *)MQTT_USERNAME;
	user_name.size = strlen(MQTT_USERNAME);
    /* to here */

	/* MQTT client configuration */
	client->broker = &broker;
	client->evt_cb = mqtt_evt_handler;
	client->client_id.utf8 = (u8_t *)CONFIG_MQTT_CLIENT_ID;
	client->client_id.size = strlen(CONFIG_MQTT_CLIENT_ID);
	client->password = &password; // Add here
	client->user_name = &user_name; // Add here
	client->protocol_version = MQTT_VERSION_3_1_0; // originally MQTT_VERSION_3_1_1

	/* MQTT buffers configuration */
	client->rx_buf = rx_buffer;
	client->rx_buf_size = sizeof(rx_buffer);
	client->tx_buf = tx_buffer;
	client->tx_buf_size = sizeof(tx_buffer);

	/* MQTT transport configuration */
	client->transport.type = MQTT_TRANSPORT_NON_SECURE;
}

.
.

void main(void)
{
	int err;

	printk("The MQTT simple sample started\n");

	modem_configure();

    /* ADD here */
    err = lte_lc_edrx_req(true);
    if (err) {
        printk("ERROR: set edrx %d\n", err);
        return;
    }
    /* ADD here */

	client_init(&client);

	err = mqtt_connect(&client);
	if (err != 0) {
		printk("ERROR: mqtt_connect %d\n", err);
		return;
	}

	err = fds_init(&client);
	if (err != 0) {
		printk("ERROR: fds_init %d\n", err);
		return;
	}

	while (1) {
		err = poll(&fds, 1, K_SECONDS(CONFIG_MQTT_KEEPALIVE)); 
		if (err < 0) {
			printk("ERROR: poll %d\n", errno);
			break;
		}

        err = mqtt_live(&client);
		if (err != 0) {
			printk("ERROR: mqtt_live %d\n", err);
			break;
		}

		if ((fds.revents & POLLIN) == POLLIN) {
			err = mqtt_input(&client); // if a publish event comes, mqtt_evt_handler is called here
			if (err != 0) {
				printk("ERROR: mqtt_input %d\n", err);
				break;
			}
		}

		if ((fds.revents & POLLERR) == POLLERR) {
			printk("POLLERR\n");
			break;
		}

		if ((fds.revents & POLLNVAL) == POLLNVAL) {
			printk("POLLNVAL\n");
			break;
		}
	}

}

This is a test condition.
Ideally, I want to set a longer keepalive value, like 1200(sec) to decrease power consumption.
- keep alive of MQTT: 1200 sec
- eDRX interval value: 655 sec

I have been struggling with this issue more than two weeks, but I don't really get the eDRX behavior. Any advice?

[Bjørn Kvaale]

Could you please open a new DevZone case? Thanks!