title: publish multiple values to thingspeak using MQTT
body: <p>I am trying to publish a multiple random data using mqtt to send data from raspberry pi to thingspeaks. i want to publish the 10 values of temp to thingspeaks field but it limits me to one value every 15 seconds. so is there anyway to send a list of values every 15 second to graph it with time in thingspeaks channels??</p>
  
  <pre><code>temp = []
  current = []
  while(1):
     # get the system performance data over 20 seconds.
     for i in range(10):
         temp.append(random.randint(0, 100))
         current.append(random.randint(0, 100))
     # build the payload string.
       payload = "field1=" + str(temp) + "&amp;field2=" + str(current)
       # attempt to publish this data to the topic.
  
       try:
           publish.single(topic, payload, hostname=mqttHost, transport=tTransport, port=tPort,auth={'username':mqttUsername,'password':mqttAPIKey})
           print (" Published temp =",temp," current =", current," to host: " , mqttHost , " clientID= " , clientID)
  
       except (KeyboardInterrupt):
           break
  
       except:
           print ("There was an error while publishing the data.")
       time.sleep(15)
  </code></pre>