/*
* FreeRTOS Kernel V10.2.1
* Copyright (C) 2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* http://www.FreeRTOS.org
* http://aws.amazon.com/freertos
*
* 1 tab == 4 spaces!
*/
/* Standard inclues. */
#include <string.h>
#include <stdio.h>
/* Kernel includes. */
#include "FreeRTOS.h"
#include "task.h"
/* IoT SDK includes. */
#include "iot_mqtt.h"
#include "iot_taskpool.h"
#include "platform/iot_network_freertos.h"
/**
* @brief The keep-alive interval used for this example.
*
* An MQTT ping request will be sent periodically at this interval.
*/
#define mqttexampleKEEP_ALIVE_SECONDS ( 60 )
/**
* @brief The timeout for MQTT operations in this example.
*/
#define mqttexampleMQTT_TIMEOUT_MS ( 5000 )
/**
* @brief The MQTT client identifier used in this example.
*/
#define mqttexampleCLIENT_IDENTIFIER "mqttexampleclient"
/**
* @brief Details of the MQTT broker to connect to.
*
* @note This example does not use TLS and therefore won't work with AWS IoT.
*
*/
#define mqttexampleMQTT_BROKER_ENDPOINT "test.mosquitto.org"
#define mqttexampleMQTT_BROKER_PORT 1883
/**
* @brief The topic to subscribe and publish to in the example.
*/
#define mqttexampleTOPIC "example/topic"
/**
* @brief The MQTT message published in this example.
*/
#define mqttexampleMESSAGE "Hello World!"
/**
* @brief Paramters to control the retry behaviour in case a QoS1 publish
* message gets lost.
*
* Retry every minutes up to a maximum of 5 retries.
*/
#define mqttexamplePUBLISH_RETRY_MS ( 1000 )
#define mqttexamplePUBLISH_RETRY_LIMIT ( 5 )
/**
* @brief The bit which is set in the demo task's notification value from the
* disconnect callback to inform the demo task about the MQTT disconnect.
*/
#define mqttexampleDISCONNECTED_BIT ( 1UL << 0UL )
/**
* @brief The bit which is set in the demo task's notification value from the
* publish callback to inform the demo task about the message received from the
* MQTT broker.
*/
#define mqttexampleMESSAGE_RECEIVED_BIT ( 1UL << 1UL )
/*-----------------------------------------------------------*/
/**
* @brief The MQTT connection handle used in this example.
*/
static IotMqttConnection_t xMQTTConnection = IOT_MQTT_CONNECTION_INITIALIZER;
/**
* @brief Parameters used to create the system task pool.
*/
static const IotTaskPoolInfo_t xTaskPoolParameters = {
/* Minimum number of threads in a task pool.
* Note the slimmed down version of the task
* pool used by this library does not autoscale
* the number of tasks in the pool so in this
* case this sets the number of tasks in the
* pool. */
2,
/* Maximum number of threads in a task pool.
* Note the slimmed down version of the task
* pool used by this library does not autoscale
* the number of tasks in the pool so in this
* case this parameter is just ignored. */
2,
/* Stack size for every task pool thread - in
* bytes, hence multiplying by the number of bytes
* in a word as configMINIMAL_STACK_SIZE is
* specified in words. */
configMINIMAL_STACK_SIZE * sizeof( portSTACK_TYPE ),
/* Priority for every task pool thread. */
tskIDLE_PRIORITY,
};
/*-----------------------------------------------------------*/
/**
* @brief The task used to demonstrate the MQTT API.
*
* @param[in] pvParameters Parmaters as passed at the time of task creation. Not
* used in this example.
*/
static void prvMQTTDemoTask( void *pvParameters );
/**
* @brief The callback invoked by the MQTT library when the MQTT connection gets
* disconnected.
*
* @param[in] pvCallbackContext Callback context as provided at the time of
* connect.
* @param[in] pxCallbackParams Contains the reason why the MQTT connection was
* disconnected.
*/
static void prvExample_OnDisconnect( void * pvCallbackContext,
IotMqttCallbackParam_t * pxCallbackParams );
/**
* @brief The callback invoked by the MQTT library when a message is received on
* a subscribed topic from the MQTT broker.
*
* @param[in] pvCallbackContext Callback context as provided at the time of
* subscribe.
* @param[in] pxCallbackParams Contain the details about the received message -
* topic on which the message was received, the received message.
*/
static void prvExample_OnMessageReceived( void * pvCallbackContext,
IotMqttCallbackParam_t * pxCallbackParams );
/**
* @brief Connects to the MQTT broker as specified in mqttexampleMQTT_BROKER_ENDPOINT
* and mqttexampleMQTT_BROKER_PORT.
*
* @note This example does not use TLS and therefore will not work with MQTT.
*/
static void prvMQTTConnect( void );
/**
* @brief Subscribes to the topic as specified in mqttexampleTOPIC.
*/
static void prvMQTTSubscribe( void );
/**
* @brief Publishes a messages mqttexampleMESSAGE on mqttexampleTOPIC topic.
*/
static void prvMQTTPublish( void );
/**
* @brief Unsubscribes from the mqttexampleTOPIC topic.
*/
static void prvMQTTUnsubscribe( void );
/**
* @brief Disconnects from the MQTT broker gracefully by sending an MQTT
* DISCONNECT message.
*/
static void prvMQTTDisconnect( void );
/*-----------------------------------------------------------*/
static void prvExample_OnDisconnect( void * pvCallbackContext,
IotMqttCallbackParam_t * pxCallbackParams )
{
TaskHandle_t xDemoTaskHandle = ( TaskHandle_t ) pvCallbackContext;
/* Ensure that we initiated the disconnect. */
configASSERT( pxCallbackParams->u.disconnectReason == IOT_MQTT_DISCONNECT_CALLED );
/* Inform the demo task about the disconnect. */
xTaskNotify( xDemoTaskHandle,
mqttexampleDISCONNECTED_BIT,
eSetBits /* Set the mqttexampleDISCONNECTED_BIT in the demo task's notification value. */
);
}
/*-----------------------------------------------------------*/
static void prvExample_OnMessageReceived( void * pvCallbackContext,
IotMqttCallbackParam_t * pxCallbackParams )
{
TaskHandle_t xDemoTaskHandle = ( TaskHandle_t ) pvCallbackContext;
/* Ensure that the message is received on the expected topic. */
configASSERT( pxCallbackParams->u.message.info.topicNameLength == strlen( mqttexampleTOPIC ) );
configASSERT( strncmp( pxCallbackParams->u.message.info.pTopicName,
mqttexampleTOPIC,
strlen( mqttexampleTOPIC ) ) == 0 );
/* Ensure that the expected message is received. */
configASSERT( pxCallbackParams->u.message.info.payloadLength == strlen( mqttexampleMESSAGE ) );
configASSERT( strncmp( pxCallbackParams->u.message.info.pPayload,
mqttexampleMESSAGE,
strlen( mqttexampleMESSAGE ) ) == 0 );
/* Ensure that the message QoS is as expected. */
configASSERT( pxCallbackParams->u.message.info.qos == IOT_MQTT_QOS_1 );
/* Although this print uses the constants rather than the data from the
* message payload the asserts above have already checked the message
* payload equals the constants, and it is more efficient not to have to
* worry about lengths in the print. */
configPRINTF( ( "Received %s on the topic %s\r\n", mqttexampleMESSAGE, mqttexampleTOPIC ) );
/* Inform the demo task about the message received from the MQTT broker. */
xTaskNotify( xDemoTaskHandle,
mqttexampleMESSAGE_RECEIVED_BIT,
eSetBits /* Set the mqttexampleMESSAGE_RECEIVED_BIT in the demo task's notification value. */
);
}
/*-----------------------------------------------------------*/
void vStartSimpleMQTTDemo( void )
{
/* This example uses a single application task, which in turn is used to
* connect, subscribe, publish, unsubscribe and disconnect from the MQTT
* broker. */
xTaskCreate( prvMQTTDemoTask, /* Function that implements the task. */
"MQTTDemo", /* Text name for the task - only used for debugging. */
configMINIMAL_STACK_SIZE, /* Size of stack (in words, not bytes) to allocate for the task. */
NULL, /* Task parameter - not used in this case. */
tskIDLE_PRIORITY, /* Task priority, must be between 0 and configMAX_PRIORITIES - 1. */
NULL ); /* Used to pass out a handle to the created task - not used in this case. */
}
/*-----------------------------------------------------------*/
static void prvMQTTDemoTask( void *pvParameters )
{
IotMqttError_t xResult;
uint32_t ulNotificationValue = 0, ulPublishCount;
const uint32_t ulMaxPublishCount = 5UL;
const TickType_t xNoDelay = ( TickType_t ) 0;
/* Remove compiler warnings about unused parameters. */
( void ) pvParameters;
/* The MQTT library needs a task pool, so create the system task pool. */
xResult = IotTaskPool_CreateSystemTaskPool( &( xTaskPoolParameters ) );
configASSERT( xResult == IOT_TASKPOOL_SUCCESS );
/* MQTT library must be initialized before it can be used. This is just one
* time initialization. */
xResult = IotMqtt_Init();
configASSERT( xResult == IOT_MQTT_SUCCESS );
for( ; ; )
{
/* Don't expect any notifications to be pending yet. */
configASSERT( ulTaskNotifyTake( pdTRUE, xNoDelay ) == 0 );
/****************************** Connect. ******************************/
/* Establish a connection to the MQTT broker. This example connects to
* the MQTT broker as specified in mqttexampleMQTT_BROKER_ENDPOINT and
* mqttexampleMQTT_BROKER_PORT at the top of this file. Please change
* it to the MQTT broker you want to connect to. Note that this example
* does not use TLS and therefore will not work with AWS IoT. */
prvMQTTConnect();
configPRINTF( ( "Connected to %s\r\n", mqttexampleMQTT_BROKER_ENDPOINT ) );
/**************************** Subscribe. ******************************/
/* The client is now connected to the broker. Subscribe to the topic
* as specified in mqttexampleTOPIC at the top of this file. This
* client will then publish to the same topic it subscribed to, so will
* expect all the messages it sends to the broker to be sent back to it
* from the broker. */
prvMQTTSubscribe();
configPRINTF( ( "Subscribed to the topic %s\r\n", mqttexampleTOPIC ) );
/*********************** Publish 5 messages. **************************/
/* Publish a few messages while connected. */
for( ulPublishCount = 0; ulPublishCount < ulMaxPublishCount; ulPublishCount++ )
{
/* Publish a message on the mqttexampleTOPIC topic as specified at
* the top of this file. */
prvMQTTPublish();
configPRINTF( ( "Published %s on the topic %s\r\n", mqttexampleMESSAGE, mqttexampleTOPIC ) );
/* Since we are subscribed to the same topic as we published on, we
* will get the same message back from the MQTT broker. Wait for the
* message to be received which is informed to us by the publish
* callback (prvExample_OnMessageReceived) by setting the
* mqttexampleMESSAGE_RECEIVED_BIT in this task's notification
* value. Note that the bit is cleared in the task's notification
* value to ensure that it is ready for next message. */
xTaskNotifyWait( 0UL, /* Don't clear any bits on entry. */
mqttexampleMESSAGE_RECEIVED_BIT, /* Clear bit on exit. */
&( ulNotificationValue ), /* Obtain the notification value. */
pdMS_TO_TICKS( mqttexampleMQTT_TIMEOUT_MS ) );
configASSERT( ( ulNotificationValue & mqttexampleMESSAGE_RECEIVED_BIT ) == mqttexampleMESSAGE_RECEIVED_BIT );
}
/******************* Unsubscribe and Disconnect. **********************/
/* Unsubscribe from the topic mqttexampleTOPIC and disconnect
* gracefully. */
prvMQTTUnsubscribe();
prvMQTTDisconnect();
configPRINTF( ( "Disconnected from %s\r\n\r\n", mqttexampleMQTT_BROKER_ENDPOINT ) );
/* Wait for the disconnect operation to complete which is informed to us
* by the disconnect callback (prvExample_OnDisconnect)by setting
* the mqttexampleDISCONNECTED_BIT in this task's notification value.
* Note that the bit is cleared in the task's notification value to
* ensure that it is ready for the next run. */
xTaskNotifyWait( 0UL, /* Don't clear any bits on entry. */
mqttexampleDISCONNECTED_BIT, /* Clear bit on exit. */
&( ulNotificationValue ), /* Obtain the notification value. */
pdMS_TO_TICKS( mqttexampleMQTT_TIMEOUT_MS ) );
configASSERT( ( ulNotificationValue & mqttexampleDISCONNECTED_BIT ) == mqttexampleDISCONNECTED_BIT );
/* Wait for some time between two iterations to ensure that we do not
* bombard the public test mosquitto broker. */
configPRINTF( ( "prvMQTTDemoTask() completed an iteration without hitting an assert. Total free heap is %u\r\n\r\n", xPortGetFreeHeapSize() ) );
vTaskDelay( pdMS_TO_TICKS( 5000 ) );
}
}
/*-----------------------------------------------------------*/
static void prvMQTTConnect( void )
{
IotMqttError_t xResult;
IotNetworkServerInfo_t xMQTTBrokerInfo;
IotMqttNetworkInfo_t xNetworkInfo = IOT_MQTT_NETWORK_INFO_INITIALIZER;
IotMqttConnectInfo_t xConnectInfo = IOT_MQTT_CONNECT_INFO_INITIALIZER;
/******************* Broker information setup. **********************/
xMQTTBrokerInfo.pHostName = mqttexampleMQTT_BROKER_ENDPOINT;
xMQTTBrokerInfo.port = mqttexampleMQTT_BROKER_PORT;
/******************* Network information setup. **********************/
/* No connection to the MQTT broker has been established yet and we want to
* establish a new connection. */
xNetworkInfo.createNetworkConnection = true;
xNetworkInfo.u.setup.pNetworkServerInfo = &( xMQTTBrokerInfo );
/* This example does not use TLS and therefore pNetworkCredentialInfo must
* be set to NULL. */
xNetworkInfo.u.setup.pNetworkCredentialInfo = NULL;
/* Use FreeRTOS+TCP network. */
xNetworkInfo.pNetworkInterface = IOT_NETWORK_INTERFACE_FREERTOS;
/* Setup the callback which is called when the MQTT connection is
* disconnected. The task handle is passed as the callback context which
* is used by the callback to send a task notification to this task.*/
xNetworkInfo.disconnectCallback.pCallbackContext = ( void * ) xTaskGetCurrentTaskHandle();
xNetworkInfo.disconnectCallback.function = prvExample_OnDisconnect;
/****************** MQTT Connection information setup. ********************/
/* Set this flag to true if connecting to the AWS IoT MQTT broker. This
* example does not use TLS and therefore won't work with AWS IoT. */
xConnectInfo.awsIotMqttMode = false;
/* Start with a clean session i.e. direct the MQTT broker to discard any
* previous session data. Also, establishing a connection with clean session
* will ensure that the broker does not store any data when this client
* gets disconnected. */
xConnectInfo.cleanSession = true;
/* Since we are starting with a clean session, there are no previous
* subscriptions to be restored. */
xConnectInfo.pPreviousSubscriptions = NULL;
xConnectInfo.previousSubscriptionCount = 0;
/* We do not want to publish Last Will and Testament (LWT) message if the
* client gets disconnected. */
xConnectInfo.pWillInfo = NULL;
/* Send an MQTT PING request every minute to keep the connection open if
there is no other MQTT traffic. */
xConnectInfo.keepAliveSeconds = mqttexampleKEEP_ALIVE_SECONDS;
/* The client identifier is used to uniquely identify this MQTT client to
* the MQTT broker. In a production device the identifier can be something
* unique, such as a device serial number. */
xConnectInfo.pClientIdentifier = mqttexampleCLIENT_IDENTIFIER;
xConnectInfo.clientIdentifierLength = ( uint16_t ) strlen( mqttexampleCLIENT_IDENTIFIER );
/* This example does not use any authentication and therefore username and
* password fields are not used. */
xConnectInfo.pUserName = NULL;
xConnectInfo.userNameLength = 0;
xConnectInfo.pPassword = NULL;
xConnectInfo.passwordLength = 0;
/* Establish the connection to the MQTT broker - It is a blocking call and
will return only when connection is complete or a timeout occurs. */
xResult = IotMqtt_Connect( &( xNetworkInfo ),
&( xConnectInfo ),
mqttexampleMQTT_TIMEOUT_MS,
&( xMQTTConnection ) );
configASSERT( xResult == IOT_MQTT_SUCCESS );
}
/*-----------------------------------------------------------*/
static void prvMQTTSubscribe( void )
{
IotMqttError_t xResult;
IotMqttSubscription_t xMQTTSubscription;
/* Subscribe to the mqttexampleTOPIC topic filter. The task handle is passed
* as the callback context which is used by the callback to send a task
* notification to this task.*/
xMQTTSubscription.qos = IOT_MQTT_QOS_1;
xMQTTSubscription.pTopicFilter = mqttexampleTOPIC;
xMQTTSubscription.topicFilterLength = ( uint16_t ) strlen( mqttexampleTOPIC );
xMQTTSubscription.callback.pCallbackContext = ( void * ) xTaskGetCurrentTaskHandle();
xMQTTSubscription.callback.function = prvExample_OnMessageReceived;
/* Use the synchronous API to subscribe - It is a blocking call and only
* returns when the subscribe operation is complete or a timeout occurs. */
xResult = IotMqtt_TimedSubscribe( xMQTTConnection,
&( xMQTTSubscription ),
1, /* We are subscribing to one topic filter. */
0, /* flags - currently ignored. */
mqttexampleMQTT_TIMEOUT_MS );
configASSERT( xResult == IOT_MQTT_SUCCESS );
}
/*-----------------------------------------------------------*/
static void prvMQTTPublish( void )
{
IotMqttError_t xResult;
IotMqttPublishInfo_t xMQTTPublishInfo;
/* Publish a message with QoS1 on the mqttexampleTOPIC topic. Since we are
* subscribed to the same topic, the MQTT broker will send the same message
* back to us. It is verified in the publish callback. */
xMQTTPublishInfo.qos = IOT_MQTT_QOS_1;
xMQTTPublishInfo.retain = false;
xMQTTPublishInfo.pTopicName = mqttexampleTOPIC;
xMQTTPublishInfo.topicNameLength = ( uint16_t ) strlen( mqttexampleTOPIC );
xMQTTPublishInfo.pPayload = mqttexampleMESSAGE;
xMQTTPublishInfo.payloadLength = strlen( mqttexampleMESSAGE );
xMQTTPublishInfo.retryMs = mqttexamplePUBLISH_RETRY_MS;
xMQTTPublishInfo.retryLimit = mqttexamplePUBLISH_RETRY_LIMIT;
/* Use the synchronous API to publish - It is a blocking call and only
* returns when the publish operation is complete or a timeout occurs. */
xResult = IotMqtt_TimedPublish( xMQTTConnection,
&( xMQTTPublishInfo ),
0, /* flags - currently ignored. */
mqttexampleMQTT_TIMEOUT_MS );
configASSERT( xResult == IOT_MQTT_SUCCESS );
}
/*-----------------------------------------------------------*/
static void prvMQTTUnsubscribe( void )
{
IotMqttError_t xResult;
IotMqttSubscription_t xMQTTSubscription;
/* Unsubscribe from the mqttexampleTOPIC topic filter. */
xMQTTSubscription.pTopicFilter = mqttexampleTOPIC;
xMQTTSubscription.topicFilterLength = ( uint16_t ) strlen( mqttexampleTOPIC );
/* The following members of the IotMqttSubscription_t are ignored by the
* unsubscribe operation. Just initialize them to avoid "use of uninitialized
* variable" warnings. */
xMQTTSubscription.qos = IOT_MQTT_QOS_1;
xMQTTSubscription.callback.pCallbackContext = NULL;
xMQTTSubscription.callback.function = NULL;
/* Use the synchronous API to unsubscribe - It is a blocking call and only
* returns when the unsubscribe operation is complete or a timeout occurs. */
xResult = IotMqtt_TimedUnsubscribe( xMQTTConnection,
&( xMQTTSubscription ),
1, /* We are unsubscribing from one topic filter. */
0, /* flags - currently ignored. */
mqttexampleMQTT_TIMEOUT_MS );
configASSERT( xResult == IOT_MQTT_SUCCESS );
}
/*-----------------------------------------------------------*/
static void prvMQTTDisconnect( void )
{
/* Send a MQTT DISCONNECT packet to the MQTT broker to do a graceful
* disconnect. */
IotMqtt_Disconnect( xMQTTConnection,
0 /* flags - 0 means a graceful disconnect by sending MQTT DISCONNECT. */
);
}
/*-----------------------------------------------------------*/