Hologram.io Nova receive message

receivefromholo.php

import time
import datetime
from Hologram.HologramCloud import HologramCloud

retvalue = "NA"
i=1

def holo_heartbeat():
    recv = hologram.sendMessage("!", topics=["heartbeat","pigate"])
    time.sleep(5) # give it time to think about it
    return recv

hologram = HologramCloud(dict(),network='cellular')
result = hologram.network.connect()
ts = time.time()
timestamp = datetime.datetime.fromtimestamp(ts).strftime('%Y-%m-%d %H:%M:%S')
message = "NovaAction.py connected to Holo."
print (message)

if result == False:
    print 'Failed to connect to cell network'
else:
    connect_time = time.time()
    try:
        hologram.openReceiveSocket()
        print "ready to receive data"
        while True:
            i += 1
            ts = time.time()
            timestamp = datetime.datetime.fromtimestamp(ts).strftime('%Y-%m-%d %H:%M:%S')
            elapsed = int(ts-connect_time)
            # print "Elapsed since last heartbeat: " + str(elapsed)
            if elapsed > 840:   # 14 minutes between heartbeats
                result = holo_heartbeat()
                message = "Heartbeat sent: " + str(result) + ". Logged."
                print (message)
                connect_time = ts
            else:    
                receivedMsg = hologram.popReceivedMessage()
                connect_status = str(hologram.network.getConnectionStatus())
                print connect_status + ' ' + timestamp + " (elapsed seconds since heartbeat: " + str(elapsed) + ") - received: " + str(receivedMsg)
                
                if len(str(receivedMsg))>4:
                    ts = time.time()
                    timestamp = datetime.datetime.fromtimestamp(ts).strftime('%Y-%m-%d %H:%M:%S')
                    if result == "invalid SMS":
                        message= result + ": " + receivedMsg
                        print message
                    else:
                        print receivedMsg
                        time.sleep(120)
                time.sleep(1)   # seconds
    except KeyboardInterrupt:
            print 'aborting the listening'
    except Exception as e:
        message = "Exception triggered" + str(e)
        print (message)
        ts = time.time()
        timestamp = datetime.datetime.fromtimestamp(ts).strftime('%Y-%m-%d %H:%M:%S')
    finally:
            hologram.closeReceiveSocket()
            hologram.network.disconnect()
  

send2holo.php

<?php
$therealdevice = "12345";
$mydevicekey = "ABCSECRET";
$mydata = "--GPIOs=5 --action=click --duration=1 --from=7025551212";
$url = “https://dashboard.hologram.io/api/1/devices/messages/$therealdevice/$mydevicekey1”;
$jsonData = array(
    ‘deviceid’ => $deviceid,
    ‘protocol’ => ‘TCP’,
    ‘port’ => 4010,
    ‘data’ => $mydata
);
$jsonDataEncoded = json_encode($jsonData);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $jsonDataEncoded);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(‘Content-Type: application/json’));
$result = curl_exec($ch);
?>

1. send2holo.php runs on a cloud server. When invoked, in real life perhaps a few times a day, it POSTs a message to the Hologram API.
2. receivefromholo.php runs on a Raspberry Pi Zero W with a Nova.
   Every second it does a hologram.popReceiveMessage().
   If there is data (as sent by send2holo.php), it grabs the data. Additional code, not included, acts on that data. It then sleeps for 2 minutes.
   You will notice code that calls a heartbeat every 840 seconds (14 minutes). The intent is to kick the socket alive by posting on the Dashboard a single byte character (!).
   Unfortunately, this doesn't work. The Dashboard always receives the ! character, for days on end. But after a few hours, send2holo.php fails with a Socket error: timed out message appearing in the Dashboard.
   The only solution is to manually restart the Pi or to do a bash hologram connect.