wattsclever.py

import csv
import datetime
import serial
import time
import urllib
import math

from time import strftime
from sense_hat import SenseHat
from decimal import Decimal
from influxdb import InfluxDBClient

# get the POC from http://www.ea.govt.nz/consumers/your-power-data-in-your-hands/my-meter/
def getGenerationPrice( time, poc ):
	params = {
		"INchoice": "SEL",
		"INdate": strftime("%d/%m/%Y"),
		"INgip": poc,
		"INperiodfrom": "1",
		"INperiodto": "50",
		"INtype": "Price",
	}
	url = "https://www.electricityinfo.co.nz/comitFta/five_min_prices.download?" + urllib.urlencode(params)
	response = urllib.urlopen(url)
	reader = csv.DictReader(response)
	row = reader.next()
	response.close()
	price = float(row["Price"])
	return price / 10 # convert $/MWh to c/kWh

# http://www.flickelectric.co.nz/downloads/price_schedules_Apr2016/Wellington-Price-Schedule-2016-04-01-v2.pdf
# Inclusive : Standard : Smart Plan Option
def getVariablePrice( time ):
	# night rate between 11pm and 7am
	if (time.tm_hour >= 23) or (time.tm_hour < 7):
		return 3.343 - 1.5
	else:
		return 6.603 - 1.5

def getElectricityPrice( poc ):
	now = time.localtime()
	gst_factor = 1.15
	generation_price = getGenerationPrice(now, poc)
	variable_price = getVariablePrice(now)
	total_price = (generation_price + variable_price) * gst_factor
	return Decimal(total_price).quantize(Decimal("1.00"))

def byte2int(bstr, width=32):
	"""
	Convert a byte string into a signed integer value of specified width.
	"""
	val = sum(ord(b) << 8*n for (n, b) in enumerate(reversed(bstr)))
	if val >= (1 << (width - 1)):
		val = val - (1 << width)
	return val

def getConsumption(port, index):
	ser = serial.Serial()
	ser.port=port
	ser.baudrate=9600
	ser.open()
	ser.write('\xaa\x02\x00\xad')
	time.sleep(1)
	output = ser.read(ser.inWaiting())
	if output == "":
		exit()
	date = int(datetime.datetime.now().strftime("%s"))
	data = [ date ]
	numb = 8
	for y in range(0, 15):
		value = int(byte2int(output[(y*numb)+5:(y*numb)+6]) + (byte2int(output[(y*numb)+6:(y*numb)+7])*256))
		if value > 12000:
			exit()
		data.append(value)
	ser.close()
	m = map(str, data)
        print m
	consumption = m[index]
	return Decimal(consumption).quantize(Decimal("1.000"))

def getTemperature(sense):
	return Decimal(sense.get_temperature()).quantize(Decimal("1.00"))

def getSeptile(value, median, deviation):
	candidates = [
		median - (deviation * 3),
		median - (deviation * 2),
		median - (deviation * 1),
		median,
		median + (deviation * 1),
		median + (deviation * 2),
		median + (deviation * 3),
	]

	# print candidates
	 #print value

	candidates.reverse()

	for idx, candidate in enumerate(candidates):
		if value > candidate:
			return len(candidates) - idx

	return 1

blank = [0, 0, 0]
yellow = [255, 230, 0]
red = [230, 0, 0]
blue = [0, 0, 230]

blankLine = [blank] * 8

colors = [
	[39, 174, 96],
	[46, 204, 113],
	[241, 196, 15],
	[243, 156, 18],
	[230, 126, 34],
	[211, 84, 0],
	[192, 57, 43],
]

def getColorLine(num):
	return colors[0:num] + ([blank] * (7 - num))

def getLine(color, num):
	return [color] + getColorLine(num)

sense = SenseHat()

price       = getElectricityPrice("CPK0111")
temperature = getTemperature(sense)
consumption = getConsumption("/dev/ttyUSB0", 3)
cost        = price * consumption/1000

priceSeptile       = getSeptile(price, 14.0, 1.0)
temperatureSeptile = getSeptile(temperature, 21.0, 3.0)
consumptionSeptile = getSeptile(consumption, 1000, 333)

print "price: %0.2f c/kWh" % (price)
print "temperature: %0.2f C" % (temperature)
print "consumption: %0.2f W" % (consumption)
print "cost: %0.2f c" % (cost)

totalCells = 32

priceCells = int(math.ceil(price))
if priceCells > totalCells:
  priceCells = totalCells

consumptionCells = int(math.ceil(consumption / 100))
if consumptionCells > totalCells:
  consumptionCells = totalCells

costCells = int(math.ceil(cost))
if costCells > totalCells:
  costCells = totalCells

cells = []
cells += [yellow] * costCells
cells += [blank] * (totalCells - costCells) 
cells += [blank] * 32

#cells += [yellow] * priceCells
#cells += [blank] * (totalCells - priceCells)
#cells += [red] * consumptionCells
#cells += [blank] * (totalCells - consumptionCells)


#inst = "%0.1f" % (price * (consumption/1000))
#inst = "%0.0f" % (price * (consumption/1000))

sense.clear()
sense.low_light = True
sense.set_pixels(cells)
#sense.show_message(inst)
#sense.show_letter(inst)

json_body = [
  {
    "measurement": "electricity_consumption",
    "tags": {
      "meter": "total_house"
    },
    "fields": { "value": consumption }
  }, {
    "measurement": "electricity_price",
    "tags": {
      "meter": "net"
    },
    "fields": { "value": price }
  }
]

print json_body

client = InfluxDBClient('10.16.64.40', 8086, "", "", "tanera")
client.write_points(json_body)