MQTT Client example program. Ethernet connection is via an ENC28J60 module.
Dependencies: UIPEthernet MQTTClient
Diff: main.cpp
- Revision:
- 2:6cd2390302ac
- Parent:
- 1:49fb5754df16
- Child:
- 3:3e5f4d503a66
--- a/main.cpp Sat Dec 20 12:04:36 2014 +0000 +++ b/main.cpp Sat Mar 21 23:45:41 2015 +0000 @@ -1,44 +1,48 @@ -// In this example an MQTT client is created using an ENC28J60 -// It is publishing a simple 'example/hello' message 'Hello World.' -// and subscribes to 'outdoor/temperature' messages -// UIPEthernet library is used to drive the ENC28J60 +// In this example an MQTT client is created. +// It is publishing a simple 'example/hello' message with payload 'Hello World.' +// and subscribes to 'outdoor/temperature' messages assumably published by other client(s). +// Ethernet connection is assured via an ENC28J60 module. #include "mbed.h" #include <UIPEthernet.h> #include <UIPClient.h> #include <MQTTClient.h> #include <string> -using namespace std; +using namespace std; + +Serial pc(USBTX, USBRX); // UIPEthernet is the name of a global instance of UIPEthernetClass. // Do not change the name! It is used within the UIPEthernet library. // Adapt the SPI pin names to your mbed platform/board if not present yet. #if defined(TARGET_LPC1768) -UIPEthernetClass UIPEthernet(p11, p12, p13, p8); // mosi, miso, sck, cs +UIPEthernetClass UIPEthernet(p11, p12, p13, p8); // mosi, miso, sck, cs #elif defined(TARGET_LPC1114) -UIPEthernetClass UIPEthernet(dp2, dp1, dp6, dp25); // mosi, miso, sck, cs +UIPEthernetClass UIPEthernet(dp2, dp1, dp6, dp25); // mosi, miso, sck, cs #elif defined(TARGET_LPC11U68) -UIPEthernetClass UIPEthernet(P0_9, P0_8, P1_29, P0_2); // mosi, miso, sck, cs -#elif defined (TARGET_NUCLEO_F103RB) -UIPEthernetClass UIPEthernet(PB_5, PB_4, PB_3, PB_6); // mosi, miso, sck, cs +UIPEthernetClass UIPEthernet(P0_9, P0_8, P1_29, P0_2); // mosi, miso, sck, cs +#elif defined(TARGET_NUCLEO_F103RB) +UIPEthernetClass UIPEthernet(PB_5, PB_4, PB_3, PB_6); // mosi, miso, sck, cs #endif -//Serial pc(PA_9, PA_10); -Serial pc(USBTX, USBRX); - - // Make sure that the MAC number is unique within the connected network. -const uint8_t MY_MAC[6] = {0x00,0x01,0x02,0x03,0x04,0x05}; +const uint8_t MY_MAC[6] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05 }; // IP address must be unique and compatible with your network too. Change as appropriate. -const IPAddress MY_IP(192,168,1,181); -char message_buff[100]; -IPAddress serverIP(192,168,1,30); // MQTT server (e.g. 'mosquitto' running on a Ubuntu PC or Raspberry Pi) -EthernetClient ethernetClient; -void onMqttMessage(char* topic, uint8_t* payload, unsigned int length); -MQTTClient mqttClient(serverIP, 1883, onMqttMessage, ethernetClient); +const IPAddress MY_IP(192, 168, 1, 181); +char message_buff[100]; +IPAddress serverIP(192, 168, 1, 30); // MQTT broker (e.g. 'Mosquitto' running on a Raspberry Pi or Linux machine) +EthernetClient ethernetClient; +void onMqttMessage(char* topic, uint8_t* payload, unsigned int length); +MQTTClient mqttClient(serverIP, 1883, onMqttMessage, ethernetClient); -int main() -{ +/** + * @brief + * @note + * @param + * @retval + */ + +int main(void) { const int MAX_COUNT = 5; int i = 0; bool connected = false; @@ -47,24 +51,27 @@ time_t lastTime = t; // initialize the ethernet device + UIPEthernet.begin(MY_MAC, MY_IP); -// IPAddress localIP = UIPEthernet.localIP(); -// pc.printf("IP = "); -// for(uint8_t i = 0; i < 3; i++) -// pc.printf("%d.", localIP[i]); -// pc.printf("%d\r\n", localIP[3]); - pc.printf("Connecting to MQTT server ..\r\n"); - do { + + // The MQTT broker is like a post office distributing messages published by clients to all subscribers (clients). + // So the 'example/hello' messages published by this client will be sent via the broker to all clients which subscribed to such messages. + // This way also this client will receive all subscribed messages (in this case 'outdoor/temperature' messages) + // published by other clients (however not directly but via the broker). + pc.printf("Connecting to MQTT broker ..\r\n"); + do + { wait(1.0); connected = mqttClient.connect("myMQTTHelloClient"); } while(!connected && (i < MAX_COUNT)); if(connected) { - pc.printf("MQTT Server connected.\r\n"); + pc.printf("MQTT broker connected.\r\n"); mqttClient.subscribe("outdoor/temperature"); pc.printf("Subscribed to: outdoor/temperature\r\n"); - } else { - pc.printf("Failed to connect to MQTT server.\r\n"); + } + else { + pc.printf("Failed to connect to MQTT broker.\r\n"); } while(1) { @@ -75,14 +82,21 @@ mqttClient.publish("example/hello", payload); pc.printf("Published: example/hello\r\n"); } + } - } mqttClient.loop(); // MQTT client loop processing } } -void onMqttMessage(char* topic, uint8_t* payload, unsigned int length) -{ +/** + * @brief Called on new MQTT message arrival + * @note + * @param topic: The topic of the new message + * payload: The payload of the new message + * length: Payload's length + * @retval + */ +void onMqttMessage(char* topic, uint8_t* payload, unsigned int length) { int i = 0; pc.printf("Message arrived:\r\n");