Zoltan Hudak / Mbed OS MQTT_Hello_ENC28J60

MQTT Client example program. Ethernet connection is via an ENC28J60 module.

Dependencies:   UIPEthernet MQTTClient

main.cpp@11:a049ad4b63c0, 2017-07-01 (annotated)

Committer:
hudakz
Date:
Sat Jul 01 09:06:43 2017 +0000
Revision:
11:a049ad4b63c0
Parent:
10:27440d67d4f2
Child:
12:3af0ae09bd01
Updated.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
hudakz 8:7b4e0d15249f 1 // In this example we create an MQTT client.
hudakz 8:7b4e0d15249f 2 // It's publishing messages with topic 'example/hello' and 'Hello World!' payload.
hudakz 8:7b4e0d15249f 3 // The MQTT client also subscribes to some topics which are in its interest to receive.
hudakz 8:7b4e0d15249f 4 // Ethernet connection is assured by an affordable ENC28J60 Ethernet module.
hudakz 0:158b106f3cfc 5 #include "mbed.h"
hudakz 11:a049ad4b63c0 6 #include "UIPEthernet.h"
hudakz 11:a049ad4b63c0 7 #include "MQTTClient.h"
hudakz 0:158b106f3cfc 8
hudakz 8:7b4e0d15249f 9 Serial pc(USBTX, USBRX);
hudakz 0:158b106f3cfc 10
hudakz 11:a049ad4b63c0 11 #define DHCP 1 // if you'd like to use static IP address comment out this line
hudakz 11:a049ad4b63c0 12
hudakz 0:158b106f3cfc 13 #if defined(TARGET_LPC1768)
hudakz 11:a049ad4b63c0 14 UIPEthernet uIPEthernet(p11, p12, p13, p8); // mosi, miso, sck, cs
hudakz 10:27440d67d4f2 15 #elif defined(TARGET_NUCLEO_F103RB) || defined(TARGET_NUCLEO_L152RE) || defined(TARGET_NUCLEO_F030R8) \
hudakz 10:27440d67d4f2 16 || defined(TARGET_NUCLEO_F401RE) || defined(TARGET_NUCLEO_F302R8) || defined(TARGET_NUCLEO_L053R8) \
hudakz 10:27440d67d4f2 17 || defined(TARGET_NUCLEO_F411RE) || defined(TARGET_NUCLEO_F334R8) || defined(TARGET_NUCLEO_F072RB) \
hudakz 10:27440d67d4f2 18 || defined(TARGET_NUCLEO_F091RC) || defined(TARGET_NUCLEO_F303RE) || defined(TARGET_NUCLEO_F070RB) \
hudakz 3:3e5f4d503a66 19 || defined(TARGET_KL25Z ) || defined(TARGET_KL46Z) || defined(TARGET_K64F) || defined(TARGET_KL05Z) \
hudakz 3:3e5f4d503a66 20 || defined(TARGET_K20D50M) || defined(TARGET_K22F) \
hudakz 3:3e5f4d503a66 21 || defined(TARGET_NRF51822) \
hudakz 3:3e5f4d503a66 22 || defined(TARGET_RZ_A1H)
hudakz 11:a049ad4b63c0 23 UIPEthernet uIPEthernet(D11, D12, D13, D10); // mosi, miso, sck, cs
hudakz 0:158b106f3cfc 24 #endif
hudakz 0:158b106f3cfc 25
hudakz 11:a049ad4b63c0 26 // MAC address must be unique within the connected network. Modify as appropriate.
hudakz 2:6cd2390302ac 27 const uint8_t MY_MAC[6] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05 };
hudakz 3:3e5f4d503a66 28
hudakz 9:18b414a8c5f7 29 // MQTT broker is like a post office.
hudakz 9:18b414a8c5f7 30 // Its task is to distribute messages published by clients to all subscribers (other clients).
hudakz 9:18b414a8c5f7 31 // So the 'example/hello' messages published by this client will be sent to the broker.
hudakz 9:18b414a8c5f7 32 // Then the broker will send them to all clients which subscribed to such topic (example/hello).
hudakz 9:18b414a8c5f7 33 // Also this client will receive all messages with topics it subscribed to (if published such by other clients).
hudakz 9:18b414a8c5f7 34 // 'Mosquitto' is a free implementation of MQTT broker for Linux (e.g. Raspberry Pi, Ubuntu etc.)
hudakz 9:18b414a8c5f7 35 IPAddress serverIP(192, 168, 1, 30); // IP address of your MQTT broker (change to match)
hudakz 9:18b414a8c5f7 36 EthernetClient ethernetClient;
hudakz 9:18b414a8c5f7 37 void onMqttMessage(char* topic, uint8_t* payload, unsigned int length);
hudakz 9:18b414a8c5f7 38 MQTTClient mqttClient(serverIP, 1883, onMqttMessage, ethernetClient);
hudakz 9:18b414a8c5f7 39 char message_buff[100]; // buffer to store received messages
hudakz 9:18b414a8c5f7 40
hudakz 2:6cd2390302ac 41 /**
hudakz 2:6cd2390302ac 42 * @brief
hudakz 2:6cd2390302ac 43 * @note
hudakz 2:6cd2390302ac 44 * @param
hudakz 2:6cd2390302ac 45 * @retval
hudakz 2:6cd2390302ac 46 */
hudakz 2:6cd2390302ac 47 int main(void) {
hudakz 8:7b4e0d15249f 48 const int MAX_TRIES = 5;
hudakz 8:7b4e0d15249f 49 const unsigned long INTERVAL = 5;
hudakz 8:7b4e0d15249f 50 int i = 0;
hudakz 8:7b4e0d15249f 51 bool connected = false;
hudakz 8:7b4e0d15249f 52 char* payload = "Hello World!";
hudakz 8:7b4e0d15249f 53 unsigned long t = 0;
hudakz 8:7b4e0d15249f 54 unsigned long lastTime = t;
hudakz 8:7b4e0d15249f 55
hudakz 3:3e5f4d503a66 56 #if defined(DHCP)
hudakz 3:3e5f4d503a66 57 pc.printf("Searching for DHCP server..\r\n");
hudakz 11:a049ad4b63c0 58 if(uIPEthernet.begin(MY_MAC) != 1) {
hudakz 3:3e5f4d503a66 59 pc.printf("No DHCP server found.\r\n");
hudakz 3:3e5f4d503a66 60 pc.printf("Exiting application.\r\n");
hudakz 3:3e5f4d503a66 61 return 0;
hudakz 3:3e5f4d503a66 62 }
hudakz 11:a049ad4b63c0 63 pc.printf("DHCP server found.\r\n");
hudakz 3:3e5f4d503a66 64 #else
hudakz 11:a049ad4b63c0 65 // IP address must be unique and compatible with your network.
hudakz 11:a049ad4b63c0 66 const IPAddress MY_IP(192, 168, 1, 181); // Change as appropriate.
hudakz 11:a049ad4b63c0 67 uIPEthernet.begin(MY_MAC, MY_IP);
hudakz 3:3e5f4d503a66 68 #endif
hudakz 11:a049ad4b63c0 69 pc.printf("Local IP = %s\r\n", uIPEthernet.localIP().toString());
hudakz 2:6cd2390302ac 70 pc.printf("Connecting to MQTT broker ..\r\n");
hudakz 11:a049ad4b63c0 71 do {
hudakz 0:158b106f3cfc 72 wait(1.0);
hudakz 0:158b106f3cfc 73 connected = mqttClient.connect("myMQTTHelloClient");
hudakz 8:7b4e0d15249f 74 } while(!connected && (i++ < MAX_TRIES));
hudakz 0:158b106f3cfc 75
hudakz 0:158b106f3cfc 76 if(connected) {
hudakz 2:6cd2390302ac 77 pc.printf("MQTT broker connected.\r\n");
hudakz 9:18b414a8c5f7 78 // We can subscribe to various topics published by other clients.
hudakz 6:fb8b9925e844 79 pc.printf("Subscribing to topics:\r\n");
hudakz 3:3e5f4d503a66 80 pc.printf(" outdoor/temperature\r\n");
hudakz 3:3e5f4d503a66 81 pc.printf(" boiler/outlet/temperature\r\n");
hudakz 8:7b4e0d15249f 82 mqttClient.subscribe("outdoor/temperature");
hudakz 8:7b4e0d15249f 83 mqttClient.subscribe("boiler/outlet/temperature");
hudakz 2:6cd2390302ac 84 }
hudakz 2:6cd2390302ac 85 else {
hudakz 2:6cd2390302ac 86 pc.printf("Failed to connect to MQTT broker.\r\n");
hudakz 0:158b106f3cfc 87 }
hudakz 0:158b106f3cfc 88
hudakz 0:158b106f3cfc 89 while(1) {
hudakz 0:158b106f3cfc 90 t = time(NULL);
hudakz 5:c0716c55b302 91 if(t > (lastTime + INTERVAL)) {
hudakz 0:158b106f3cfc 92 lastTime = t;
hudakz 0:158b106f3cfc 93 if(connected) {
hudakz 8:7b4e0d15249f 94 pc.printf("Publishing: example/hello\r\n");
hudakz 0:158b106f3cfc 95 mqttClient.publish("example/hello", payload);
hudakz 0:158b106f3cfc 96 }
hudakz 2:6cd2390302ac 97 }
hudakz 3:3e5f4d503a66 98 mqttClient.loop(); // MQTT client loop processing (receiving messages)
hudakz 0:158b106f3cfc 99 }
hudakz 0:158b106f3cfc 100 }
hudakz 0:158b106f3cfc 101
hudakz 2:6cd2390302ac 102 /**
hudakz 2:6cd2390302ac 103 * @brief Called on new MQTT message arrival
hudakz 8:7b4e0d15249f 104 * @note
hudakz 2:6cd2390302ac 105 * @param topic: The topic of the new message
hudakz 2:6cd2390302ac 106 * payload: The payload of the new message
hudakz 2:6cd2390302ac 107 * length: Payload's length
hudakz 2:6cd2390302ac 108 * @retval
hudakz 2:6cd2390302ac 109 */
hudakz 2:6cd2390302ac 110 void onMqttMessage(char* topic, uint8_t* payload, unsigned int length) {
hudakz 0:158b106f3cfc 111 int i = 0;
hudakz 0:158b106f3cfc 112
hudakz 0:158b106f3cfc 113 pc.printf("Message arrived:\r\n");
hudakz 3:3e5f4d503a66 114 pc.printf(" Topic: %s\r\n", topic);
hudakz 3:3e5f4d503a66 115 pc.printf(" Length: %d\r\n", length);
hudakz 0:158b106f3cfc 116
hudakz 0:158b106f3cfc 117 // create character buffer with ending null terminator (string)
hudakz 0:158b106f3cfc 118 for(i = 0; i < length; i++) {
hudakz 0:158b106f3cfc 119 message_buff[i] = payload[i];
hudakz 0:158b106f3cfc 120 }
hudakz 0:158b106f3cfc 121
hudakz 0:158b106f3cfc 122 message_buff[i] = '\0';
hudakz 9:18b414a8c5f7 123 pc.printf(" Payload: %s\r\n", message_buff);
hudakz 0:158b106f3cfc 124 }