Need help with Setting & Calculating Variables

My goal is pretty simple: I want to take my current electricity usage in kWh and multiply it by my current Time-of-Use rate from the utility, and display the current cost on a custom control page.

I am using the TED Home plugin to get my current usage in kWh, and have a bunch of Indigo schedules that set a variable called currentElectricityRate. This is because my utility went to a complicated TOU schedule that TED back-end cannot support correctly.

My thought was if I could have 2 variables (kWh usage from TED and TOU rate set from my Indigo schedules), I could do a simple multiplication, and the 3rd variable would be my current cost, which I could display in a custom control page. So something like this:

currentPowerNowTotal * currentElectricityRate = currentCost

I am having 2 challenges:

1. Getting the kWh usage (function is called PowerNow_Total in TED Plugin) into a variable that I can work with
2. Setting up an action (python script?) that multiplies the 2 variables to get my 3rd variable (currentCost)

If I'm understanding, this should be pretty close:

Code: Select all

#! /usr/bin/env python
# -*- coding: utf-8 -*-

kwh = float(indigo.devices[ID GOES HERE].states['PowerNow_Total'])
rate = float(indigo.variables[ID GOES HERE].value)

cost = kwh * rate

indigo.variable.updateValue(ID GOES HERE, str(cost))  # variables must be stored as strings


This is awesome, it works great. One little thing: the variable value has a lot of extra decimal places.

Is there a way to just round up or truncate like these examples:
0.2007 becomes 0.20
0.2051 becomes 0.21

Of course!

Code: Select all

#! /usr/bin/env python
# -*- coding: utf-8 -*-

kwh = float(indigo.devices[ID GOES HERE].states['PowerNow_Total'])
rate = float(indigo.variables[ID GOES HERE].value)

cost = kwh * rate

# indigo.variable.updateValue(ID GOES HERE, str(cost))  # variables must be stored as strings
# indigo.variable.updateValue(ID GOES HERE, u"{0:.0f}".format(cost))  # variables must be stored as strings / 0 decimals
# indigo.variable.updateValue(ID GOES HERE, u"{0:.10f}".format(cost))  # variables must be stored as strings / 10 decimals

indigo.variable.updateValue(ID GOES HERE, u"{0:.1f}".format(cost))  # variables must be stored as strings / 1 decimal


I will give this a go when I am back in front of a computer.

Thank you so much for the help!

Just wanted to say that your code worked great.

Thank You.

Glad to hear that it worked for you.

Python's "format specifiers' are really useful. It's a wonder that Matt doesn't use them more often.