NB-IoT 27: MQTT subscribe
This example shows how to subscribe MQTT topic
Required Materials
1 x Waspmote 1 x Battery 1 x NB-IoT / Cat-M module 2 x NB-IoT / Cat-M antenna 1 x SIM card
Notes
- The battery has to be connected. - This example can be executed in Waspmote v15
Code
/*
--- NB_IoT_27 - MQTT subscribe ---
Explanation: This example shows how to subscribe MQTT topic
Copyright (C) 2019 Libelium Comunicaciones Distribuidas S.L.
http://www.libelium.com
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see .
Version: 3.0
Design: David Gascón
Implementation: P.Moreno, J.Siscart
*/
#include
// APN settings
char apn[] = "";
char login[] = "";
char password[] = "";
///////////////////////////////////////
// Operator selection
///////////////////////////////////////
char network_operator[] = "21401";
///////////////////////////////////////
// options:
// LALPHANUMERIC_OPERATOR Long format alphanumeric which can be up to 16 characters long.
// SALPHANUMERIC_OPERATOR Short format alphanumeric .
// NUMERIC_OPERATOR Numeric . GSM location area identification number.
///////////////////////////////////////
uint8_t operator_type = NUMERIC_OPERATOR;
///////////////////////////////////////
// Band configuration
///////////////////////////////////////
// NB-IoT & LTE-M1 bands:
// B1
// B2
// B3
// B4
// B5
// B8
// B12
// B13
// B18
// B19
// B20
// B26
// B28
// B39
// ------------------------------------
// GSM bands:
// GSM900
// GSM1800
// GSM850
// GSM1900
// GSM_ANYBAND
// NB_ANYBAND
// M1_ANYBAND
/////////////////////////////////////
char band[] = B20;
/////////////////////////////////////
// SERVER MQTT settings
///////////////////////////////////////
char mqtt_server[] = "51.77.40.223";
uint16_t mqtt_port = 1883;
char mqtt_user[] = ""; // User name of the client. It can be used for authentication.
char mqtt_pass[] = ""; // Password corresponding to the user name of the client. It can be used for authentication.
char mqtt_clientID[] = "clienteID"; // The client identifier string.
//-------------------------------------
char mqtt_topic[] = "test/test1";
// The QoS level at which the client wants to publish the messages.
// 0 At most once
// 1 At least once
// 2 Exactly once
uint8_t qos = 2;
uint16_t msgID = 0; //Message identifier of packet. The range is 0-65535. It will be 0 only when =0
///////////////////////////////////////
// define variables
int error;
uint32_t previous;
void setup()
{
USB.ON();
USB.println(F("Start program"));
//////////////////////////////////////////////////
// 1. sets operator parameters
//////////////////////////////////////////////////
BG96.set_APN(apn, login, password);
//////////////////////////////////////////////////
// 2. Show APN settings via USB port
//////////////////////////////////////////////////
BG96.show_APN();
}
void loop()
{
//////////////////////////////////////////////////
// 1. Switch ON
//////////////////////////////////////////////////
error = BG96.ON();
if (error == 0)
{
USB.println(F("1. NB-IoT module ready..."));
////////////////////////////////////////////////
// 2.1. Check connection to network and continue
////////////////////////////////////////////////
error = BG96.nbiotConnection(apn, band, network_operator, operator_type);
if (error == 0)
{
USB.println(F("2.1. NB-IoT connection: OK "));
////////////////////////////////////////////////
// 2.2.1 NB-IoT Context Activation
////////////////////////////////////////////////
error = BG96.contextActivation(1,5);
if (error == 0)
{
USB.println(F("2.2.1. NB-IoT context connection: OK "));
USB.print(F("IP: ")); USB.println(BG96._ip);
////////////////////////////////////////////////
// 3. Setting DNS server
////////////////////////////////////////////////
error = BG96.setDNSServer("8.8.8.8","8.8.4.4");
if (error == 0)
{
USB.println(F("3. Setting DNS server: OK "));
}
else
{
USB.println(F("3. DNS error: ")); USB.println(error,DEC);
USB.println(BG96._buffer, BG96._length);
}
////////////////////////////////////////////////
// 4.1. MQTT open session
////////////////////////////////////////////////
error = BG96.mqttOpenSession(mqtt_server, mqtt_port, mqtt_clientID, mqtt_user, mqtt_pass);
// check answer
if (error == 0)
{
USB.println(F("4.1. MQTT open session OK"));
previous = millis();
//////////////////////////////////////////////
// 4.2. MQTT session status
//////////////////////////////////////////////
//MQTT connection state
// 1 MQTT is initial
// 2 MQTT is connecting
// 3 MQTT is connected
// 4 MQTT is disconnecting
error = BG96.mqttSessionStatus();
if (error == 0)
{
USB.print(F("4.2. MQTT session status: "));
USB.println(BG96._mqtt_status, DEC);
}
else
{
USB.print(F("4.2. Error calling 'mqttSessionStatus' function. error: "));
USB.println(error, DEC);
}
//////////////////////////////////////////////
// 4.3. MQTT subscribe a topic
//////////////////////////////////////////////
error = BG96.mqttSubscribe(mqtt_topic, qos);
if (error == 0)
{
USB.println(F("4.3. MQTT subscribe message OK"));
USB.print(F("Topic subscribe: ")); USB.println(mqtt_topic);
}
else
{
USB.print(F("4.3. Error calling 'mqttSubscribe' function. error: "));
USB.println(error, DEC);
}
//////////////////////////////////////////////
// 4.4. MQTT waitting data from a topic
//////////////////////////////////////////////
// message struct: ,,
USB.println(F("4.4. Waitting data from MQTT server topic:"));
error = BG96.mqttWaittingData(60000);
if (error == 0)
{
USB.print(F("4.4. MQTT message received: "));
USB.println(BG96._buffer, BG96._length);
}
else
{
USB.print(F("4.4. Error calling 'mqttWaittingData' function. error: "));
USB.println(error, DEC);
}
//////////////////////////////////////////////
// 4.5. MQTT unsubscribe a topic
//////////////////////////////////////////////
error = BG96.mqttUnsubscribe(mqtt_topic);
if (error == 0)
{
USB.println(F("4.5. MQTT unsubscribe message OK"));
}
else
{
USB.print(F("4.5. Error calling 'mqttUnsubscribe' function. error: "));
USB.println(error, DEC);
}
//////////////////////////////////////////////
// 4.6. MQTT close session
//////////////////////////////////////////////
error = BG96.mqttCloseSession();
if (error == 0)
{
USB.println(F("4.6. MQTT close session OK"));
}
else
{
USB.print(F("4.6. Error calling 'mqttCloseSession' function. error: "));
USB.println(error, DEC);
}
}
else
{
USB.print(F( "4.1. MQTT open session ERROR: "));
USB.println(error, DEC);
}
}
}
else
{
// Problem with the communication with the NB-IoT module
USB.println(F("NB-IoT module not started"));
USB.print(F("Error code: "));
USB.println(error, DEC);
}
}
////////////////////////////////////////////////
// 5. Powers off the NB-IoT module
////////////////////////////////////////////////
USB.println(F("5. Switch OFF NB-IoT module"));
error = BG96.OFF();
if (error == 0)
{
USB.println(F("5. Module is power off"));
}
else
{
USB.println(F("5. Power off ERROR"));
}
////////////////////////////////////////////////
// 6. Sleep
////////////////////////////////////////////////
USB.println(F("6. Enter deep sleep..."));
PWR.deepSleep("00:00:00:10", RTC_OFFSET, RTC_ALM1_MODE1, ALL_OFF);
USB.ON();
USB.println(F("7. Wake up!!\n\n"));
}
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