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:
- 2014-09-15
- Revision:
- 0:092b5e724233
- Child:
- 1:4be688be4e0d
File content as of revision 0:092b5e724233:
// In this example an MQTT client is created. // It is publishing parameters measured by a DHT11 sensor // UIPEthernet library is used to drive the ENC28J60 board #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}; // 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); IPAddress serverIP(192,168,1,30); // MQTT server (e.g. 'mosquitto' running on a Raspberry Pi or Ubuntu) EthernetClient ethernetClient; void onMqttMessage(char* topic, uint8_t* payload, unsigned int length); MQTTClient mqttClient(serverIP, 1883, onMqttMessage, ethernetClient); const int PERIOD = 10; // seconds Serial pc(USBTX, USBRX); int main() { const int MAX_COUNT = 5; int i = 0; bool connected = false; time_t t = 0; time_t lastTime = 0; // initialize the ethernet device Ethernet.begin(MY_MAC, MY_IP); pc.printf("Connecting to MQTT server ..\r\n"); do { wait(1.0); connected = mqttClient.connect("myMqttClient"); } while(!connected && (i < MAX_COUNT)); if(connected) { pc.printf("MQTT Server connected.\r\n"); mqttClient.subscribe("rt_clock"); pc.printf("Subscribed to: "); pc.printf("rt_clock\r\n"); } else { pc.printf("Failed to connect to MQTT server.\r\n"); } while(1) { t = time(NULL); if(t >= (lastTime + PERIOD)) { lastTime = t; if(connected) { sprintf(message_buff, "%ds:\r\n", t); pc.printf("---------------------\r\n"); pc.printf(message_buff); 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 } } 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); }