Continuously reads power values from an Aerotec Energy Meter with pyopenzwave

read_aerotec_energy_meter_with_pyopenzwave.py

import time
from openzwave.option import ZWaveOption
from libopenzwave import PyManager
import csv
from matplotlib import pyplot

device="/dev/ttyUSB0"
options = ZWaveOption(device, config_path="/etc/openzwave/", user_path=".", cmd_line="")
options.set_console_output(False)
options.lock()


class PowerMeter(PyManager):
    def __init__(self):
        super(PowerMeter, self).__init__()
        self.create()
        self.addWatcher(self.callback)
        time.sleep(1.0)
        self.addDriver(device)
        self.meter_values = []
        self.start_time = None
        self.units = None
        self.value_id = {}

    def get_meter_values(self, num_seconds):
        self.start_time = time.time()
        while time.time() - self.start_time < num_seconds:
            time.sleep(0.10)
            if self.value_id:
                assert self.refreshValue(self.value_id)

    def callback(self, zwargs):
        # get the node id/home from the first message tagged with the sensor we want
        if "valueId" in zwargs:
            if zwargs["valueId"]["commandClass"] == "COMMAND_CLASS_METER":
                if zwargs["valueId"]["label"] == "Power" and \
                                zwargs["valueId"]["instance"] == 1 \
                        and self.start_time is not None:
                    self.value_id = zwargs["valueId"]["id"]
                    self.units = zwargs["valueId"]["units"]
                    self.meter_values.append((time.time() - self.start_time,
                                              zwargs["valueId"]["value"]))
                    print("Power", zwargs["valueId"]["value"])


manager = PowerMeter()
# collect data for an hour
manager.get_meter_values(60*60)
# add to a csv
with open('meter_values_%s.csv' % manager.start_time, 'wb') as csvfile:
    spamwriter = csv.writer(csvfile, delimiter=',', quoting=csv.QUOTE_MINIMAL)
    spamwriter.writerow(['time (s)', 'meter (%s)' % manager.units])
    for row in manager.meter_values:
        spamwriter.writerow(row)

fig, ax = pyplot.subplots()
ax.plot([point[0]/60.0 for point in manager.meter_values],
            [point[1] for point in manager.meter_values])
ax.set_xlabel("Time (minutes)")
ax.set_ylabel("Meter Value (%s)" % manager.units)
fig.savefig("power_meter_%s.png" % manager.start_time)