main.cpp

00001 // In this project an MQTT client is created.
00002 // It is publishing parameters measured by a DHT11 sensor.
00003 // Ethernet connection is assured via an ENC28J60 module.
00004 
00005 #include "mbed.h"
00006 #include "UIPEthernet.h"
00007 #include "MQTTClient.h"
00008 #include "DHT11.h"
00009 
00010 Serial          pc(USBTX, USBRX);
00011 
00012 // MAC address must be unique within the connected network. Modify as appropriate.
00013 const uint8_t   MY_MAC[6] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05 };
00014 
00015 #define DHCP    1   // comment out this line if you'd like to use static IP address
00016 
00017 #if !defined(DHCP)
00018 // In case you'd like to use static IP address:
00019 // IP address must be unique and compatible with your network.
00020 // Change as appropriate.
00021 const IPAddress MY_IP(192, 168, 1, 181);
00022 #endif
00023 
00024 // uIPEthernet is the name of a global instance of UIPEthernet.
00025 // Do not change the name! It is used within the UIPEthernet library.
00026 // Adapt the SPI pin names to your mbed platform/board if not present yet.
00027 
00028 #if defined(TARGET_LPC1768)
00029 UIPEthernet  uIPEthernet(p11, p12, p13, p8);         // mosi, miso, sck, cs
00030 DHT11        dht11(p6);
00031 #elif defined(TARGET_NUCLEO_F103RB) || defined(TARGET_NUCLEO_L152RE) || defined(TARGET_NUCLEO_F030R8)  \
00032    || defined(TARGET_NUCLEO_F401RE) || defined(TARGET_NUCLEO_F302R8) || defined(TARGET_NUCLEO_L053R8)  \
00033    || defined(TARGET_NUCLEO_F411RE) || defined(TARGET_NUCLEO_F334R8) || defined(TARGET_NUCLEO_F072RB)  \
00034    || defined(TARGET_NUCLEO_F091RC) || defined(TARGET_NUCLEO_F303RE) || defined(TARGET_NUCLEO_F070RB)  \
00035    || defined(TARGET_KL25Z ) || defined(TARGET_KL46Z) || defined(TARGET_K64F) || defined(TARGET_KL05Z) \
00036    || defined(TARGET_K20D50M) || defined(TARGET_K22F) \
00037    || defined(TARGET_NRF51822) \
00038    || defined(TARGET_RZ_A1H)
00039 UIPEthernet  uIPEthernet(D11, D12, D13, D10);        // mosi, miso, sck, cs
00040 DHT11        dht11(PC_14);
00041 #endif
00042 
00043 char  message_buff[100];
00044 void  onMessage(char* topic, uint8_t* payload, unsigned int length);
00045 
00046 // MQTT broker is like a post office.
00047 // Its task is to distribute messages published by clients to all subscribers (other clients).
00048 // So messages published by this client will be sent to the broker.
00049 // Then the broker will send them to all clients which subscribed to such topics.
00050 // Also this client will receive all messages with topics it subscribed to.
00051 // 'Mosquitto' is a free implementation of MQTT broker for Linux machines (e.g. Raspberry Pi, Ubuntu etc.)
00052 IPAddress       serverIP(192, 168, 1, 30);  // IP address of your MQTT broker (adapt)
00053 EthernetClient  ethernetClient;
00054 void            onMqttMessage(char* topic, uint8_t* payload, unsigned int length);
00055 MQTTClient      mqttClient(serverIP, 1883, onMqttMessage, ethernetClient);
00056 const int       INTERVAL = 10;  // Interval for publishing messages (in seconds)
00057 
00058 
00059 /**
00060  * @brief   Main
00061  * @note
00062  * @param
00063  * @retval
00064  */
00065 int main(void) {
00066     const int   MAX_COUNT = 5;
00067     int         i = 0;
00068     bool        connected = false;
00069     time_t      t = 0;
00070     time_t      lastTime = 0;
00071 
00072     // initialize the ethernet device
00073     
00074 #if defined(DHCP)
00075     pc.printf("Searching for DHCP server..\r\n");
00076  
00077     if (uIPEthernet.begin(MY_MAC) != 1) {
00078         pc.printf("No DHCP server found.\r\n");
00079         pc.printf("Exiting application.\r\n");
00080         return 0;
00081     }
00082     pc.printf("DHCP server found and configuration info received.\r\n");
00083 #else
00084     uIPEthernet.begin(MY_MAC, MY_IP);
00085 #endif
00086     pc.printf("Local IP = %s\r\n", uIPEthernet.localIP().toString());       
00087     pc.printf("Connecting to MQTT broker ..\r\n");
00088     do {
00089         wait(1.0);
00090         connected = mqttClient.connect("myMqttClient");
00091     } while(!connected && (i < MAX_COUNT));
00092 
00093     if (connected) {
00094         pc.printf("MQTT broker connected.\r\n");
00095         // The client can subscribe to as many MQTT messages as you like.
00096         mqttClient.subscribe("example/hello"); 
00097         mqttClient.subscribe("boiler/outlet/temperature");
00098         pc.printf("Subscribed to:\r\n");
00099         pc.printf("    example/hello\r\n");
00100         pc.printf("    boiler/outlet/temperature\r\n");
00101     }
00102     else {
00103         pc.printf("Failed to connect to MQTT broker.\r\n");
00104     }
00105 
00106     while (1) {
00107         t = time(NULL);
00108         if(t >= (lastTime + INTERVAL)) {
00109             lastTime = t;
00110             if(connected) {
00111                 pc.printf("---------------------\r\n");
00112                 pc.printf("%ds:\r\n", t);
00113 
00114                 int state = dht11.readData();
00115                 if(state == DHT11::OK) {
00116                     float   hum = dht11.readHumidity();
00117                     sprintf(message_buff, "%4.1f", hum);
00118                     pc.printf("  hum = %s%%\r\n", message_buff);
00119                     mqttClient.publish("outdoor/humidity", message_buff);
00120 
00121                     float   temp = dht11.readTemperature();
00122                     sprintf(message_buff, "%5.1f", temp);
00123                     pc.printf("  temp = %s'C\r\n", message_buff);
00124                     mqttClient.publish("outdoor/temperature", message_buff);
00125 
00126                     float   dewPoint = temp - (100 - hum) / 5.0;
00127                     sprintf(message_buff, "%5.1f", dewPoint);
00128                     pc.printf("  dew point = %s'C\r\n", message_buff);
00129                     mqttClient.publish("outdoor/dewpoint", message_buff);
00130                 }
00131                 else
00132                     pc.printf("  DHT11 error: %d\r\n", state);
00133             }
00134         }
00135 
00136         mqttClient.loop();  // MQTT client loop processing
00137     }
00138 }
00139 
00140 /**
00141  * @brief   Called on new MQTT message arrival
00142  * @note    
00143  * @param   topic:      The topic of the new message
00144  *          payload:    The payload of the new message
00145  *          length:     Payload's length
00146  * @retval
00147  */
00148 void onMqttMessage(char* topic, uint8_t* payload, unsigned int length) {
00149     int i = 0;
00150 
00151     pc.printf("Message arrived:\r\n");
00152     pc.printf("    Topic: %s\r\n", topic);
00153     pc.printf("    Length: %d\r\n", length);
00154 
00155     // create character buffer with ending null terminator (string)
00156     for (i = 0; i < length; i++) {
00157         message_buff[i] = payload[i];
00158     }
00159 
00160     message_buff[i] = '\0';
00161     pc.printf("    Payload: %s\r\n", message_buff);
00162 }
00163