Monitoring Electricity Usage

Simple one, this one…

We wanted to see exactly how much power we were using, and wanted to be able to display this information to staff.

First off, you need a monitoring device. I opted for the CurrentCost Envi with the optional data lead (and two more sensors as we’re on three phase!)

Next, you download the driver from the CurrentCost site. Then you plug the monitor into your USB port. In theory it’s now pumping data into COM3 at 56700 baud. Ace.

A quick check with HyperTerminal (you have to go hunting for this, it died with XP!) and sure as hell… we have some data coming in. The Envi pumps in the current readings at 6 second intervals. Cool.

Now, a teeny tiny bit of code in VB.Net gets the data into your app. With .NET 3.5 you get a nice SerialPort control. Drag one of those onto your form, and then add this code:

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
SerialPort1.PortName = "COM3"
SerialPort1.BaudRate = 57600
SerialPort1.Handshake = IO.Ports.Handshake.None
SerialPort1.Open()
End Sub

Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived

Dim datain As String = ""
datain = SerialPort1.ReadLine()
System.Diagnostics.Debug.Print(datain)

End Sub

 

Tada!!!! You now have live electricity readings from within your app, coming in nice XML blobs like this:

<?xml version="1.0" encoding="utf-8" ?>

<msg>
  <src>CC128-v0.12</src>
  <dsb>00001</dsb>
  <time>12:38:19</time>
  <tmpr>18.5</tmpr>
  <sensor>0</sensor>
  <id>00077</id>
  <type>1</type>
  <ch1>
    <watts>02330</watts>
  </ch1>
</msg>

 

A bit of XML jiggery pokery and you have a reasonably accurate data feed of your power readings in your SQL server.

To see what I did with the data, have a look at the JAM Blog

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s