File content as of revision 2:5191c0e163d6:

#include "mbed.h"
#include "EthernetNetIf.h"
#include "HTTPClient.h"
#include "ThingSpeak.h"

Serial pc(USBTX, USBRX);

ThingSpeak::ThingSpeak(char* Key) : thingSpeakKey(Key) {      
    thingSpeakUrl = "https://api.thingspeak.com/update";
    thingSpeakRead = "https://api.thingspeak.com/channels/";
    urlBuffer[0] = 0;
    fieldBuffer[0] = 0;
}

 float ThingSpeak::pull(long int readKey, int field) {
    sprintf(urlBuffer, "%s%d/fields/%d/last", thingSpeakRead, readKey, field ); 
    pc.printf("URL Buffer request: %s ", urlBuffer); 
    res = http.get(urlBuffer, &resp);
    if (res == HTTP_OK){
        pc.printf(" Result :\"%s\"\r\n,", resp.gets(), res);
        float resp2 = atoi(resp.gets());
        return resp2;
        }
    else {
        pc.printf(" Error %d\r\n", res); 
        return false;
    }      
}

void ThingSpeak::connect() {
    pc.printf("Setting up Ethernet...\r\n");
    EthernetErr ethErr = eth.setup();
    if(ethErr){
        pc.printf("Error %d in ethernet setup.\r\n", ethErr);  
        connect();
        }
    pc.printf("Ethernet setup OK\r\n");
}

void ThingSpeak::setField(float field, int i) {
    char fieldi;
    char fieldShortBuff[8];
    sprintf(fieldShortBuff, "%f", field);
    sprintf(&fieldi, "%i", i);
    strncat(fieldBuffer, "&field", 6 );
    strncat(fieldBuffer, &fieldi , 1);
    strncat(fieldBuffer, "=", 1);
    strncat(fieldBuffer, fieldShortBuff , 6);    
}

void ThingSpeak::putUp() {
    sprintf(urlBuffer, "%s?key=%s%s", thingSpeakUrl, thingSpeakKey, fieldBuffer);
    pc.printf("URL Buffer request: %s ", urlBuffer); 
    res = http.get(urlBuffer, &resp);
    if (res == HTTP_OK)
        pc.printf(" Result :\"%s\"\r\n", resp.gets());
    else
        pc.printf(" Error %d\r\n", res); 
    fieldBuffer[0] = 0;         
}