ESP8266 / Mbed 2 deprecated ESP8266_MQTT_HelloWorld

Example MQTT implemented on the ESP8266

Dependencies:   ESP8266Interface MQTT mbed-rtos mbed

Fork of HelloMQTT by MQTT

This is an example of how to run MQTT using the esp8266 as the network connection. This program will default to trying to talk to a public MQTT server (test.mosquitto.org). The example will subscribe to a topic and then publish to that topic. In this way it will effectively echo back to itself. You can alternatively use a private mqtt broker,[[TODO: |instructions here]]

Please note that the ESP8266 interface cannot translate hostnames to IP Addresses, it can only accept raw IP Addresses as input.

Linux-example/LinuxIPStack.h

Committer:
mbedAustin
Date:
2015-06-09
Revision:
18:76d0899bc3ce
Parent:
8:a3e3113054a1

File content as of revision 18:76d0899bc3ce:

#if !defined(LINUX_IPSTACK_H)
#define LINUX_IPSTACK_H

class IPStack 
{
public:    
    IPStack()
    {

    }
    
    int Socket_error(const char* aString)
    {

        if (errno != EINTR && errno != EAGAIN && errno != EINPROGRESS && errno != EWOULDBLOCK)
        {
            if (strcmp(aString, "shutdown") != 0 || (errno != ENOTCONN && errno != ECONNRESET))
                printf("Socket error %s in %s for socket %d\n", strerror(errno), aString, mysock);
        }
        return errno;
    }

    int connect(const char* hostname, int port)
    {
        int type = SOCK_STREAM;
        struct sockaddr_in address;
        int rc = -1;
        sa_family_t family = AF_INET;
        struct addrinfo *result = NULL;
        struct addrinfo hints = {0, AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, 0, NULL, NULL, NULL};

        if ((rc = getaddrinfo(hostname, NULL, &hints, &result)) == 0)
        {
            struct addrinfo* res = result;

            /* prefer ip4 addresses */
            while (res)
            {
                if (res->ai_family == AF_INET)
                {
                    result = res;
                    break;
                }
                res = res->ai_next;
            }

            if (result->ai_family == AF_INET)
            {
                address.sin_port = htons(port);
                address.sin_family = family = AF_INET;
                address.sin_addr = ((struct sockaddr_in*)(result->ai_addr))->sin_addr;
            }
            else
                rc = -1;

            freeaddrinfo(result);
        }

        if (rc == 0)
        {
            mysock = socket(family, type, 0);
            if (mysock != -1)
            {
                int opt = 1;

                //if (setsockopt(mysock, SOL_SOCKET, SO_NOSIGPIPE, (void*)&opt, sizeof(opt)) != 0)
                //  printf("Could not set SO_NOSIGPIPE for socket %d", mysock);
                
                rc = ::connect(mysock, (struct sockaddr*)&address, sizeof(address));
            }
        }

        return rc;
    }

    int read(char* buffer, int len, int timeout_ms)
    {
        struct timeval interval = {timeout_ms / 1000, (timeout_ms % 1000) * 1000};
        if (interval.tv_sec < 0 || (interval.tv_sec == 0 && interval.tv_usec <= 0))
        {
            interval.tv_sec = 0;
            interval.tv_usec = 100;
        }

        setsockopt(mysock, SOL_SOCKET, SO_RCVTIMEO, (char *)&interval, sizeof(struct timeval));

        //printf("reading %d bytes\n", len);
        int rc = ::recv(mysock, buffer, (size_t)len, 0);
        if (rc == -1)
            Socket_error("read");
        //printf("read %d bytes\n", rc);
        return rc;
    }
    
    int write(char* buffer, int len, int timeout)
    {
        struct timeval tv;

        tv.tv_sec = 0;  /* 30 Secs Timeout */
        tv.tv_usec = timeout * 1000;  // Not init'ing this can cause strange errors

        setsockopt(mysock, SOL_SOCKET, SO_RCVTIMEO, (char *)&tv,sizeof(struct timeval));
        int rc = ::write(mysock, buffer, len);
        //printf("write rc %d\n", rc);
        return rc;
    }

    int disconnect()
    {
        return ::close(mysock);
    }
    
private:

    int mysock; 
    
};

#endif