Merge pull request #19 from sparkfun/add_mqtt_example

Add MQTT Example

Author: sfe-SparkFro

examples/Example8_MQTT/Example8_MQTT.ino

@@ -0,0 +1,268 @@
+#include "SparkFun_u-blox_Cellular_Arduino_Library.h"
+
+// Uncomment the line below that you need for Serial on your platform
+#define mySerial Serial1
+// SoftwareSerial mySerial(16, 17);
+
+// Uncomment the module you're using. If your module is not listed below, then
+// it's not supported for this example
+SparkFun_ublox_Cellular myModule; // This example works with all modules, so the base class can be used
+// SparkFun_ublox_SARA_R5 myModule; // Base SARA-R5 class
+// SparkFun_ublox_SARA_R500S myModule;
+// SparkFun_ublox_SARA_R500S_01B myModule;
+// SparkFun_ublox_SARA_R500S_61B myModule;
+// SparkFun_ublox_SARA_R510M8S_61B myModule;
+// SparkFun_ublox_SARA_R510S myModule;
+// SparkFun_ublox_LARA_R6 myModule; // Base LARA-R6 class
+// SparkFun_ublox_LARA_R6001 myModule;
+// SparkFun_ublox_LARA_R6001D myModule;
+// SparkFun_ublox_LARA_R6401 myModule;
+// SparkFun_ublox_LARA_R6401D myModule;
+// SparkFun_ublox_LARA_R6801_00B myModule;
+// SparkFun_ublox_LARA_R6801D myModule;
+
+// You can change the Quality of Service (QoS) here if you want
+int qos = 0;
+
+// Topics that will be used for publishing and subscribing
+String publishTopic;
+String subscribeTopic;
+
+// Whether we're connected to the MQTT broker
+bool mqttConnected = false;
+
+// Callback function for handling MQTT responses from the module
+void mqttCallback(int command, int result)
+{
+    if (command == UBX_CELL_MQTT_COMMAND_LOGIN && result == 1)
+    {
+        // Connected to broker
+        mqttConnected = true;
+        Serial.println(F("Connected to broker!"));
+    }
+    else if (command == UBX_CELL_MQTT_COMMAND_LOGOUT && result == 1)
+    {
+        // Disconnected from broker
+        mqttConnected = false;
+        Serial.println(F("Disconnected from broker!"));
+    }
+    else if (command == UBX_CELL_MQTT_COMMAND_SUBSCRIBE && result == 1)
+    {
+        // Topic subscription successful
+        Serial.println(F("Subscribed to topic!"));
+        Serial.println(F("Enter any text to post to the topic"));
+        Serial.println();
+    }
+    else if (command == UBX_CELL_MQTT_COMMAND_READ)
+    {
+        // New message available
+        Serial.print(F("A new message is available! Total messages to read: "));
+        Serial.println(result);
+        Serial.println(F("Enter a blank line to read the oldest message"));
+        Serial.println();
+    }
+    else
+    {
+        // Other response
+        Serial.print(F("Unknown MQTT reponse! Command: "));
+        Serial.print(command);
+        Serial.print(F(" Result: "));
+        Serial.println(result);
+    }
+}
+
+void setup()
+{
+    String currentOperator = "";
+
+    Serial.begin(115200); // Start the serial console
+
+    // Wait for user to press key to begin
+    Serial.println(F("u-blox Cellular Example 8 - MQTT"));
+    Serial.println(F("Press any key to begin"));
+
+    while (!Serial.available()) // Wait for the user to press a key (send any serial character)
+        ;
+    while (Serial.available()) // Empty the serial RX buffer
+        Serial.read();
+
+    Serial.println(F("Beginning..."));
+
+    // myModule.enableDebugging(); // Uncomment this line to enable helpful debug messages on Serial
+
+    // For the MicroMod Asset Tracker, we need to invert the power pin so it pulls high instead of low
+    // Uncomment the next line if required
+    // myModule.invertPowerPin(true);
+
+    // Initialize the module
+    if (myModule.begin(mySerial, UBX_CELL_DEFAULT_BAUD_RATE))
+    {
+        Serial.println(F("Module connected!"));
+    }
+    else
+    {
+        Serial.println(F("Unable to communicate with the module."));
+        Serial.println(F("Manually power-on (hold the module's On button for 3 seconds) and try again."));
+        while (1)
+            ; // Loop forever on fail
+    }
+    Serial.println();
+
+    // First check to see if we're connected to an operator:
+    if (myModule.getOperator(&currentOperator) == UBX_CELL_SUCCESS)
+    {
+        Serial.print(F("Connected to: "));
+        Serial.println(currentOperator);
+    }
+    else
+    {
+        Serial.print(F("The module is not yet connected to an operator. Please use the previous examples to connect. "
+                       "Or wait and retry. Freezing..."));
+        while (1)
+            ; // Do nothing more
+    }
+
+    Serial.println();
+
+    // Make sure any previous MQTT connection is closed
+    myModule.disconnectMQTT();
+
+    // Set callback for any MQTT responses from the module
+    myModule.setMQTTCommandCallback(mqttCallback);
+
+    Serial.println(F("Enter the MQTT broker server name"));
+
+    // Clear any previous input and wait for new input
+    while (Serial.available())
+        Serial.read();
+    while (!Serial.available())
+        ;
+
+    // Get the broker server name
+    String serverName = Serial.readStringUntil('\n');
+    Serial.print(F("Server name: "));
+    Serial.println(serverName);
+    Serial.println();
+
+    Serial.println(F("Enter the MQTT broker server port number"));
+    Serial.println(F("(or enter nothing for default port of 1883)"));
+
+    // Clear any previous input and wait for new input
+    while (Serial.available())
+        Serial.read();
+    while (!Serial.available())
+        ;
+
+    // Get the broker server port
+    String serverPort = Serial.readStringUntil('\n');
+
+    // Attempt to parse the port number. If it fails, just set 1883
+    int port = serverPort.toInt();
+    if (port == 0)
+        port = 1883;
+
+    Serial.print(F("Server port: "));
+    Serial.println(port);
+    Serial.println();
+
+    // Now set the MQTT server
+    myModule.setMQTTserver(serverName, port);
+
+    Serial.println(F("Enter the client ID"));
+
+    // Clear any previous input and wait for new input
+    while (Serial.available())
+        Serial.read();
+    while (!Serial.available())
+        ;
+
+    // Get the client ID
+    String clientID = Serial.readStringUntil('\n');
+    Serial.print(F("Client ID: "));
+    Serial.println(clientID);
+    Serial.println();
+
+    // Set the client ID
+    myModule.setMQTTclientId(clientID);
+
+    Serial.println(F("Connecting to MQTT broker..."));
+    myModule.connectMQTT();
+
+    // Wait for module to connect
+    while (!mqttConnected)
+        myModule.poll();
+
+    Serial.println();
+    Serial.println(F("Enter a topic to publish to"));
+
+    // Clear any previous input and wait for new input
+    while (Serial.available())
+        Serial.read();
+    while (!Serial.available())
+        ;
+
+    // Get the topic name
+    publishTopic = Serial.readStringUntil('\n');
+    Serial.print(F("Publish topic: "));
+    Serial.println(publishTopic);
+    Serial.println();
+
+    Serial.println();
+    Serial.println(F("Enter a topic to subscribe to"));
+
+    // Clear any previous input and wait for new input
+    while (Serial.available())
+        Serial.read();
+    while (!Serial.available())
+        ;
+
+    // Get the topic name
+    subscribeTopic = Serial.readStringUntil('\n');
+    Serial.print(F("Subscribe topic: "));
+    Serial.println(subscribeTopic);
+    Serial.println();
+
+    // Subscribe to the topic
+    myModule.subscribeMQTTtopic(qos, subscribeTopic);
+}
+
+void loop()
+{
+    // Need to call poll() frequently to receive updates from the module.
+    myModule.poll();
+
+    // Check for user input
+    if (Serial.available())
+    {
+        // Get user's input
+        String inputString = Serial.readStringUntil('\n');
+
+        // Clear any remaining input
+        while (Serial.available())
+            Serial.read();
+
+        // Check whether the user entered anything
+        if (inputString.length() > 0)
+        {
+            // Publish the user's input to the topic
+            Serial.println(F("Publishing message:"));
+            Serial.println(inputString);
+            Serial.println();
+            myModule.mqttPublishTextMsg(publishTopic, inputString.c_str());
+        }
+        else
+        {
+            // Read next received message
+            uint8_t buffer[MAX_MQTT_DIRECT_MSG_LEN];
+            int bytesRead = 0;
+            myModule.readMQTT(&qos, &subscribeTopic, buffer, MAX_MQTT_DIRECT_MSG_LEN, &bytesRead);
+
+            // Print out message
+            Serial.println(F("Received message:"));
+            for (int i = 0; i < bytesRead; i++)
+                Serial.print((char)buffer[i]);
+            Serial.println();
+            Serial.println();
+        }
+    }
+}