thingspeak

#!/usr/bin/env python
# To run: set environment variable REDIS_URL to the input instance, 
# and pass the ThingSpeak channel ID and API write key as the CLI arguments:
# $ REDIS_URL="redis://input_host" ./thingspeak TS_CHANNEL_ID TS_CHANNEL_API_WRITE_KEY
# set LOC to a (LAT, LNG) tuple if you want to include location information

import time
import json
import urllib
import urllib2
import sys
from datetime import datetime
from rpjios.SubscriberBase import PSubscriber

SEND_EVERY = 20 # samples
FIELDS = ['mc_1p0', 'mc_2p5', 'mc_4p0', 'mc_10p0', 'nc_0p5', 'nc_2p5', 'nc_10p0', 'typical_particle_size']
CHANNEL_ID = int(sys.argv[1]) 
API_WRITE_KEY = sys.argv[2]
LOC = None
WRITE_URL = "https://api.thingspeak.com/update.json?api_key={}".format(API_WRITE_KEY)

msg_c = 1
def msg_rx(msg):
    global msg_c
    if not msg_c % SEND_EVERY:
        _d = json.loads(msg["data"])
        (ts, val) = (_d["ts"], _d["value"])
        _pl = { 
                "created_at": datetime.fromtimestamp(ts).isoformat(),
                "channel_id": CHANNEL_ID
            }
        if LOC is not None:
            _pl["latitude"] = LOC[0]
            _pl["longitude"] = LOC[1]
        for fi in range(0, len(FIELDS)):
            _pl["field{}".format(fi+1)] = val[FIELDS[fi]]
        _params = urllib.urlencode(_pl)
        _url = "{}&{}".format(WRITE_URL, _params)
        _resp = urllib2.urlopen(_url)
        _rread = _resp.read()
        _rc = _resp.getcode()
        try:
            if _rc != 200:
                print "Request failure ({})! URL: {}".format(_rc, _url)
            elif type(_rread) == str:
                print "Success: entry #{} added".format(json.loads(_rread)["entry_id"])
            else:
                print "Unknown failure: {} {}".format(_rc, _rread)
        except Exception as e:
            print "Unknown failure: {} ({})".format(e, _rc)
        msg_c = 1
    msg_c += 1

p = PSubscriber("*SPS30*").add_listener(msg_rx)

while 1:
    time.sleep(0.5)