MQ Telemetry Transport client publishing parameters measured by a DHT11 sensor. Ethernet connection is via an ENC28J60 module.
Dependencies: DHT11 MQTTClient UIPEthernet mbed
Fork of MQTT_DHT11_ENC28J60 by
main.cpp
- Committer:
- hudakz
- Date:
- 2015-03-21
- Revision:
- 2:f706efb3ea13
- Parent:
- 1:4be688be4e0d
- Child:
- 3:de6cc3ff5aaa
File content as of revision 2:f706efb3ea13:
// In this project an MQTT client is created. // It is publishing parameters measured by a DHT11 sensor. // Ethernet connection is assured via an ENC28J60 module. #include <mbed.h> #include <UIPEthernet.h> #include <UIPClient.h> #include <MQTTClient.h> #include <DHT11.h> // 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 DHT11 dht11(p6); #elif defined(TARGET_NUCLEO_F103RB) UIPEthernetClass UIPEthernet(PB_5, PB_4, PB_3, PB_6); // mosi, miso, sck, cs DHT11 dht11(PC_14); #endif // Make sure that the MAC number is unique within the connected network. const uint8_t MY_MAC[6] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05 }; // This client is using a static IP address. Make sure DHCP is disabled on your router/modem. // 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]; void onMessage(char* topic, uint8_t* payload, unsigned int length); // In case your MQTT broker has different IP adress modify the following definition accordingly. IPAddress serverIP(192, 168, 1, 30); // MQTT broker (e.g. 'Mosquitto' running on a Raspberry Pi or Linux device) // The MQTT broker is like a post office distributing messages received from publishing clients to all subscribers (clients). // So the 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 from other clients, but via the broker. EthernetClient ethernetClient; void onMqttMessage(char* topic, uint8_t* payload, unsigned int length); MQTTClient mqttClient(serverIP, 1883, onMqttMessage, ethernetClient); const int PERIOD = 10; // period for publishing the messages (in seconds) Serial pc(USBTX, USBRX); /** * @brief Main * @note * @param * @retval */ int main(void) { const int MAX_COUNT = 5; int i = 0; bool connected = false; time_t t = 0; time_t lastTime = 0; // initialize the ethernet device UIPEthernet.begin(MY_MAC, MY_IP); pc.printf("Connecting to MQTT broker ..\r\n"); do { wait(1.0); connected = mqttClient.connect("myMqttClient"); } while(!connected && (i < MAX_COUNT)); if(connected) { pc.printf("MQTT broker connected.\r\n"); // The client can subscribe to as many MQTT messages as you like. mqttClient.subscribe("outdoor/gasmeter"); mqttClient.subscribe("livingroom/temperature"); mqttClient.subscribe("boiler/outlet/temperature"); } else { pc.printf("Failed to connect to MQTT broker.\r\n"); } while(1) { t = time(NULL); if(t >= (lastTime + PERIOD)) { lastTime = t; if(connected) { pc.printf("---------------------\r\n"); pc.printf("%ds:\r\n", t); int state = dht11.readData(); if(state == DHT11::OK) { float hum = dht11.readHumidity(); sprintf(message_buff, "%4.1f", hum); pc.printf(" hum = %s%%\r\n", message_buff); mqttClient.publish("outdoor/humidity", message_buff); float temp = dht11.readTemperature(); sprintf(message_buff, "%5.1f", temp); pc.printf(" temp = %s'C\r\n", message_buff); mqttClient.publish("outdoor/temperature", message_buff); float dewPoint = temp - (100 - hum) / 5.0; sprintf(message_buff, "%5.1f", dewPoint); pc.printf(" dew point = %s'C\r\n", message_buff); mqttClient.publish("outdoor/dewpoint", message_buff); } else pc.printf(" DHT11 error: %d\r\n", state); } } mqttClient.loop(); // MQTT client loop processing } } /** * @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"); pc.printf(" Topic: %s\r\n", topic); pc.printf(" Length: %d\r\n", length); // create character buffer with ending null terminator (string) for(i = 0; i < length; i++) { message_buff[i] = payload[i]; } message_buff[i] = '\0'; pc.printf(" Payload: %s\r\n", message_buff); }