• Previously I mentioned an “ERASE” mode, this is actually “EXCLUDE” mode. This mode should only be used if your thermostat was previously installed in a z-wave network, I guess this was the case when I first set-up my thermostat. The protocol reset does more or less the same but is more extensive. It removes any network information from the HRT4-ZW and returns it to the factory default state (The double press of the dial is to avoid accidental operation)
• The way incorporate the devices with a controller (in my case the Aeon Labs Z-Stick) is to start with both in an unassigned state. Install each device separately on to your controller. The Association between the two devices may be done using the ‘A’ command on the HRT4-ZW and pressing the install button on the ASR. This does not require knowledge of the node numbers. The install (network) button is required for installation. You need to hold the button down for over a second.
• I forgot to mention about the wake-up time, I changed the wake-up time while it was in the LI (listen) mode. The default wake-up time is around 23 hours, which is a bit long when you want your thermostat changed. I changed it to 256 seconds or in other words 4 minutes and 16 seconds (the bare minimum value), but I might change it to a higher value again later on.. please see the point below why..
• The 2 year battery life (as reported by Horstmann) is based on normal use as a stand-alone thermostat. Use in a network where the HRT4-ZW is woken up regularly will reduce this time. That’s why there is a minimum wake-up interval. Battery life should not be a problem in practice, but please note that when the HRT4-ZW is in installer mode (switch 1 up) the Z-Wave module is permanently powered and takes much more power. This is why my battery life reported 90% after some tests. 0% is 2V and 100% is 3V or above. A new set of batteries will normally give just over 3V (2xAAA, 1.5v each)
• There is actually a second and third configuration parameter I forgot to mention about. The second one allows you to change to Fahrenheit messages. The third one allows you to set a delta t for reporting temperature changes. A message will be sent to associated nodes if the temperature changes by delta t. This parameter defaults to 1°C.
• When controlled by Z-Wave messages rather than turning the dial, you can actually set the setpoint to 0.1°C steps. This will not show up on the display as it’s only 2 digits, but it will attempt to control to it. For example you could set the setpoint to 20.6°C if you wished. 21°C will be shown on the display as the demand temperature is rounded up. Fahrenheit temperatures are converted internally to the nearest 0.1°C so will not give you more accuracy.

Some really valuable additional information, thanks a lot Mr.Anonymous ! :-)

• Control the setpoint
• Get a setpoint report when it is manually changed (also notifications of battery levels and the room temperature)
• Get the actual room temperature

There are several posts on the Micasa Verde and Homeseer forums that device is not working in their software, despite this fact I decided to take the risk and order this device. The total cost including shipping costs was just under €100.
The HRT4-ZW is a thermostat system that consists of two devices, one controller (the user side of the system, where you control the set point etc.) and a receiver (this one needs to be attached to your HVAC system). Here’s a picture of both devices:

Getting my feet wet: the first steps

The first step I took when I got the device was creating a test setup, I connected an old PC power supply cable to the receiver (it needs 230v). Put in the batteries of the controller device and I was good to go! I decided the first step I had to take was getting values from the device (temperature, current set point and battery level as a bonus). Horstmann has provided detailed z-wave information in a separate document, available here.
One of the requirements for me was to include the controller device into my existing z-wave network, that appears to be a pretty trivial task. But, it turned out it was one of the most difficult tasks.
I completely read through the z-wave document over and over again, but after 2 evenings of playing around with I was about to give up. The L mode as described in the document does include the controller within an existing z-wave network, but that loses the connection with the device that you attach to your HVAC.
Separately re-associating that unit is not an option as the network button on the device does not do anything. Or, maybe it can be used?
I figured out that once you put the controller unit into ERASE mode, the receiver network LED will blink as if it is ready for association. This turned out to be the key to getting both nodes included within my existing z-wave network! Here are the steps in detail:

1) Put the thermostat into program mode (dip switch 1 into position ON)
2) Select the P option, double click the rotary wheel until PP appears on the display.
3) Now go to the E, for ERASE mode. Click the rotary wheel once again until the E starts blinking.
4) At this point the receiver network LED should be blinking, this means the node is ready for inclusion.
5) Now, remove the batteries from the controller! Yes, just do it :-)
6) Include the receiver by pushing the include button on your z-wave network stick (in my case an Aeon Labs z-stick), after that press the network button on the receiver until the ON led starts to blink.
7) The receiver is now included!
8) Include the controller by using the L function as described in the z-wave documentation.

You should now end up with two thermostat devices in your z-wave network. Here’s a screenshot from HouseAgent:

Node number 3 is the receiver and node 4 is the controller. Node 3 is quite useless (it doesn’t report any z-wave classes, except basic) but it needs to be included within the same network in order to work with the controller. Here are the z-wave classes reported by the controller, again a screenshot from HouseAgent:

Please note that the controller is a sleeping z-wave device, requests for this device need to be queued until the device comes available. The device will send a wakeup notification once it comes online. You can queue commands to the controller, and when it gets online send these commands.

Associations

In order to receive updates from the controller once a value changes you need to set associations. The thermostat supports associations for unsollicited room temperature, setpoint and battery reports. I set associations for each of these reports to my z-wave stick. Here’s an overview of my configuration (more information of the specifications of these groups can be found in the Horstmann document):

Setting the setpoint

This was my final task to be actually able to control the thermostat. Because this is a sleepjng device commands need to be queued, this was an easy thing to do in open-zwave. The problem was however that my Python z-wave wrapper had no support for setting values.. yet. I commited a new version of my open-zwave python wrapper, with setvalue support to github!

Here’s an example of the setvalue command being executed after the device woke up:


2011-05-19 20:10:01:771 Received Wakeup Notification from node 4
2011-05-19 20:10:01:772 Node 4 has been marked as awake
2011-05-19 20:10:01:774 Queuing command: Set Thermostat Setpoint (Node=4): 0x01, 0x0c, 0x00, 0x13, 0x04, 0x05, 0x43, 0x01, 0x01, 0x01, 0x0f, 0x05, 0x09, 0xa0
2011-05-19 20:10:01:817 Sending command (Callback ID=0x09, Expected Reply=0x13) - Set Thermostat Setpoint (Node=4): 0x01, 0x0c, 0x00, 0x13, 0x04, 0x05, 0x43, 0x01, 0x01, 0x01, 0x0f, 0x05, 0x09, 0xa0
2011-05-19 20:10:01:822 ACK received CallbackId 0x09 Reply 0x13
2011-05-19 20:10:01:825 Received: 0x01, 0x04, 0x01, 0x13, 0x01, 0xe8
2011-05-19 20:10:01:828 ZW_SEND_DATA delivered to Z-Wave stack
2011-05-19 20:10:01:838 Received: 0x01, 0x05, 0x00, 0x13, 0x09, 0x00, 0xe0
2011-05-19 20:10:01:840 ZW_SEND_DATA Request with callback ID 0x09 received (expected 0x09)
2011-05-19 20:10:01:845 Expected reply was received
2011-05-19 20:10:01:869 Message transaction complete


Physical/electrical connections

I was unsure about the electrical connections required from the receiver to my HVAC, so I decided to hook up two wires to the points I expected to be the required connections. After that I tested it with the continuity function of my multimeter. Here’s a video of my test setup:

Parameters

One more sidenote, there are two configuration parameters available. Configuration parameter 1 must be set in order for room temperature reporting to work! This does not work out of the box..

This concludes my long post about this thermostat, next up for me is creating a nice GUI for it… now that I got everything figured out.

After playing around a bit with (works just fine!) I decided to open it.. why? Just because I can :-)
Opening this things was a piece of cake, just mind that there is a Torx T7 screw in the right bottom corner. It’s hidden underneath the information label:

Here are some pictures of the board itself:

Frontside of the Home Base PCB.

Backside of the Home Base PCB.

There are two interesting headers on the board (1×6 pin and 1x2x7 pin), I will play around with them a bit later on (in fact, I already did.. I’ll just save that for a later blog post..):

To be continued..

This is how it looks:

And this is how it looks on a (solder less) breadboard:

Great stuff, thanks Steve!

In this post I will explain how to connect a serial console to your Linksys WRT320N router!

Remember the solder pads from the last post? Here’s a closeup image:

The pads are labeled, it’s a serial connection. Connecting only the RX/TX signals and the GND signal is sufficient.
Please note that you need a logic level converter (such as a max232, or telephone datacables) to convert the signal.

Now that we have a possibility to connect to the console of the router, we can all sorts of cool stuff. Including interrupting the bootloader to flash a new firmware image!
Here’s a boot log of the router with a dd-wrt (big) image:


CFE version 1.0.37 for BCM947XX (32bit,SP,LE)
Build Date: Fri Jul 24 07:15:00 EDT 2009 (root@Raymond.Lai)
Copyright (C) 2000,2001,2002,2003 Broadcom Corporation.

Fortunately I could wrap around it with a little regular screwdriver (didn’t have any security torx driver handy, who does anyway?)
Here’s a picture of the case from the inside (note the three, damn small antenna’s):

Here’s a picture of the hardware board:

But wait.. what’s the soldered wire down the bottom left? [teaser]We will talk about that in the next blog post :-)[/teaser]

# Number of days to generate, default = 365
$NumDays 		= 365
$AccessGroup 	= "Gasten"
$ExpiryTime 	= "20:00"
$StartTime 		= "07:00"
$OutputCSV		= "C:\TEMP\wireless.csv"

$SshHost 		= "127.0.0.1"
$SshUser		= "someuser"

$access_codes = @()

# Start SSH session
New-SshSession $SshUser $SshHost
Invoke-Ssh "z"
Invoke-Ssh "conf t"
Invoke-Ssh "wireless F"
Invoke-Ssh "conf t"
Invoke-Ssh "radius-server local"

$i = 0;
do {
	# WSEM format: mm/dd/yyyy hh:mm
	$date = (Get-Date).AddDays($i)
	$date2 = Get-Date $date -Format "dd-MM-yyyy"
	$date = Get-Date $date -format "MM:dd:yyyy"
	$pass = RandomPassword 4
	$user = RandomPassword 4
	$output = "rad-user $user password 0 $pass group $AccessGroup guest expiry-time $ExpiryTime expiry-date $date start-time $StartTime start-date $date"

	# add user through SSH
	Invoke-ssh $output

	$Response = New-Object PSObject
	Add-Member -InputObject $Response -MemberType NoteProperty -Name "Datum" -Value $date2
	Add-Member -InputObject $Response -MemberType NoteProperty -Name "Gebruikersnaam" -Value $user
	Add-Member -InputObject $Response -MemberType NoteProperty -Name "Wachtwoord" -Value $pass
	$access_codes += $Response

	$i++;
} while ( $i -le $NumDays )

# Save and disconnect SSH
Invoke-ssh "write mem"
Remove-SshSession

# Export to CSV
$access_codes | Export-Csv $OutputCSV

# Helper functions
function RandomPassword ([int]$intPasswordLength)
{
   $strNumbers = "1234567890"
   $strCapitalLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
   $strLowerLetters = "abcdefghijklmnopqrstuvwxyz"
   $rand = new-object random

   for ($a=1; $a -le $intPasswordLength; $a++)
      {
         if ($a -gt 3)
           {
      	      $b = $rand.next(0,3) + $a
      	      $b = $b % 3 + 1
      	   } else { $b = $a }
      	 switch ($b)
      	   {
      	      "1" {$b = "$strNumbers"}
      	      "2" {$b = "$strCapitalLetters"}
      	      "3" {$b = "$strLowerLetters"}
      	   }
         $charset = $($b)
         $number = $rand.next(0,$charset.Length)
         $RandomPassword += $charset[$number]
      }
   return $RandomPassword
}

Special thanks to Joel Bennett’s SharpSSH wrapper for PowerShell (located here: http://huddledmasses.org/scriptable-ssh-from-powershell/) which I used to automate the command line commands for the HP WSEM.
This shows the great power of PowerShell for automating virtually anything!