Extra display option for Proliphix NT20e

One of the items shown on the LCD of the Proliphix NT20e IP thermostat is the Device name. First i had it set to the location of the thermostat, so there was “Livingroom” displayed. Not very usefull, i know where the thermostat is, since i only have one.  Next text i displayed was my last name… even less informative, i know who i am… OK, another item for my to-do list: can this line of text on the display be used for something really usefull?

Then Pieter Knuvers came with a very good idea; why not display the outside temperature and humidity here? Good idea! Tonight i had some time to have a look at it: 🙂

Outside temp on Proliphix LCD

Outside temp on Proliphix LCD

Proliphix NT20e Thermostat online

Today i created the beginning of a page that will show real-time information about the Proliphix thermostat i started using yesterday. Although not finished yet, it displays some status information and will be extended with several charts to see all you ever wanted to know. But for that, I’ll have to wait a while to have some data to work with. Click on the image to go to my website.

Website Thermostat page

Website Thermostat page

Proliphix NT20e in use

This morning, when i got out of bed, i knew i had a job to do: my Home Automation system was going to be extended with the Proliphix NT20e Thermostat.

All worked well last night with the thermostat on my desk in the office, so drilling a few holes and placing the NT20e in the living room wouldn’t take more then a couple of hours.

However, one little detail took me a couple of hours more then i expected.
This detail was the fact that a Remeha Calenta with an outside temperature sensor doesn’t react on on/off thermostats… it took me some time to figure this out

Once i found out what was going wrong, the NT20e was mounted very easily.

NT20 back plate mounted to the wall
Proliphix NT20 mounted to the wall

Next thing to do was creating a kind of ‘demonstration’ that it all worked. I chose the touchscreen in the living room to be the first GUI to get the new feature of changing the thermostat set point. The touchscreen is 30 cm away from the thermostat, but who cares 🙂

NT20 thermostat and ASUS TOP GUI

NT20e thermostat and ASUS TOP GUI

I created a screen with a “+” and “-” button like this:

Setting Thermostat set point in GUI

Setting Thermostat set point in GUI

When a button is pressed, the numeric value in the middle that represents the new desired thermostat setpoint, gets a different color:

Setting Thermostat set point in GUI

Setting Thermostat set point in GUI

When neither the “+” or “-” are pressed for a period of 3 seconds, the numeric value returns to its previous color and the current value is sent to my Domotica system, which takes care of posting the new value of the set-point to the thermostat.

Setting Thermostat set point in GUI

Setting Thermostat set point in GUI

My conclusion so far about this Proliphix thermostat: the greatest thermostat I’ve ever seen.

But this is not the end of the story, there’s still a lot to be done!

Interface with Proliphix NT20e IP Thermostat

After unpacking, connecting and testing the NT20e the time had come to start testing the software i had already made in the past days to let my HA system interface with the thermostat.

With the very good and accurate Proliphix API documentation available, it was quite easy to start coding for the API without actual hardware to test with. The object oriented architecture i use in my Home Automation system really paid off this time. I mean, a thermostat with dozens of values/settings that can be read or written, is something completely different then for example a Door/Window sensor. Or not?

No, it doesn’t have to be. Whether you’re dealing with a thermostat or whatever type of sensor, they are both Devices with 1 or more DeviceValues. So all i had to do is focus on the device-specific code and ‘rewrite’ the API information to Delphi code. For example the code to define all the types and constants is 900 lines of code, the code that does the actual low-level interfacing with the NT20e is 430 lines and the code for the NT20e itself is 400 lines. In total less then 2000 lines of code of which only 1000 executable, not bad! The less new code means less new bugs 🙂

The result of these 1000 lines of code is total integration in the rest of my HA system. Complete exposure of the thermostat and its functionality: storing historical data to the database, creating events, manipulating the thermostat from the website, touchscreen or one of my other GUIs, everything instantly available.

Sometimes i am very glad i chose to create my own Home Automation system 3 years ago… this is one of those times :-).

Testing the interface. Before the thermostat would be placed on the wall in the livingroom, i wanted to make sure the interface was working properly. Only some minor bugs were found, mainly caused by making mistakes in translating the API documentation into constants. Currently the NT20e interface is running on my PC where it will run for some time before i am confident enough to take the next step: relocating the thermostat to the livingroom and start using it 🙂

Testing my Domotica system with the NT20e

Testing my Domotica system with the NT20e

Connecting the Proliphix NT20e thermostat

Ethernet and power

Needless to say that connecting this IP thermostat needs an Ethernet connection nearby. Fortunately i have a 1Gbps switch only 3 meters away from the place where the thermostat will be placed. The thermostat also needs 24V DC power to operate. POE (Power Over Ethernet) is being used to power the NT20e. An EPA-20 can be used to inject the power into the Ethernet cable that goes to the thermostat:

Proliphix EPA-20

Proliphix EPA-20

The EPA-20 is capable of powering 2 devices (not necessarily being Proliphix thermostats).

Dry testing

Before connecting the thermostat to my central heating, i decided to do some ‘dry’ tests first: connecting the Ethernet cable and power, but not the 2 wires that go to the central heating. I attached a multimeter to the connections i thought were the right ones for the combination of my central heating (Remeha Calenta) and the NT20e. My guess was i had to use the connections labeled RH and W1, so i monitored what was happening on these 2 connections when the relay switched. I tested voltage and resistance; and as i expected, no voltage is applied and resistance was either 0 or infinite; exactly the behavior i expected (and need).

Proliphix NT20e back plate

Proliphix NT20e back plate

Back side of the NT20e thermostat

Back side of the NT20e thermostat

The thermostat is ready to be used, but first: testing the interface to my Home Automation system with the thermostat still in the office! (will save me a lot of running from office to living and back again while testing) 🙂

Proliphix NT20e IP Thermostat

Yesterday i received a NT20e IP Thermostat made by Proliphix:

NT20e IP Thermostat and EPA-20 Power supply

As a logical followup on the Remeha Gateway disaster where in the end i was forced to disconnect the Gateway, my attention shifted towards using a thermostat to achieve my goal: being able to change the setpoint of the central heating from my Home Automation system. I’ve looked at several products, and in my opinion the Proliphix Uniphy Network Thermostats looked the best in terms of offered functionality, connectivity and professionalism. Pieter Knuvers from Bwired and i discussed this thermostat and Pieter was just as enthusiastic about this thermostat as i was. Pieter and i do a lot of things together; testing hardware is one of those things. Last Thursday a Proliphix NT20e and a POE Power injector arrived from the USA. Pieter received the same parts and we started testing.

– Compatible with fossil (oil, gas) as well as heat pump systems
– Support for Single stage heat and Airconditioning
– Wired TCP/IP communication
– Password protected, built-in Web Browser control interface (TMI)
– Email alerts
– Support for 2 additional external sensors
– 366 day programming
– 4 temperature periods per day
– 3 year scheduling
– Scheduling of vacation and other special days
– Energy Star compliant.

The first looks after the NT20e confirmed my expectations – the Proliphix Thermostat looks and feels very sound.

– It weighs more then the average thermostat i’ve ever held in my hands;
– The buttons on the front give a good, solid ‘click’;
– The LCD is backlit which makes it very good readable;
– The internals look solid and firm, good for years & years of operation.

One minor thing i think that could use some attention is the thickness; the dimensions of the NT20e are 14.2 x 9.5 x 4.3  cm.
This is quite thick, however you have to keep in mind that this thermostat has a lot to offer – more then the usual Dutch thermostat i know of, so that will probably cause the slightly higher volume.

This thermostat is the ultimate tool to achieve what i’ve wanted for years and years, even before i knew what Domotica meant: controlling the temperature setpoint without having to stand in front of the thermostat!

Remeha: "problem not important enough"

Today, after 5 weeks of waiting, i was called by a Remeha employee about my problems with the combination of Remeha equipment in my house: Remeha Calenta, Gateway and Celcia 20.

I told him the whole story from the beginning; the phone calls i made with Remeha in April this year to be sure that what i wanted would work, the problems i encountered, the emails to Remeha sales support about the problems, more phonecalls and not getting any answer from Remeha for more than 5 weeks now.

The bottom line is that Remeha is to busy with new developments to pay any attention to what problems i might be experiencing with this very rare combination of their hardware. Simply a matter of costs.  Investing time/money into this matter costs more then and the relevance of the problem is very low for Remeha.

So basically the answer i got today was: “we’re sorry”. Ok. Bad answer for me; i’m not happy with it. But in a way, i can understand it. But this was the first time i was talking to a Remeha person who had the guts to say it out loud… it hurt (a bit), but this is 10 times better than getting no answer at all. That’s really irritating and disrespectful; ever heard of after-sales? The Remeha employee apologized for that.

And before i metioned anything about it, I was told i could return the Gateway and defective Celcia without any problem and i would get my money back. Case closed… regarding doing it the Remeha-way i mean : I’m already one step further in accomplishing what i want another way…

Modulating OpenTherm Thermostat behavior

A few days ago i was cleaning up my office and found a cable with a 1-Wire DS1820 Temperature sensor connected to it. I completely forgot about that… before we got our new Remeha central heating, i had this sensor connected to the pipe through which the hot water flows to the radiators.

I added a second DS1820 to the cable, plugged the cable back into the HA7Net, connected the sensors to the pipes for incoming and outgoing water and started logging the temperatures to the database. Of course, this was a good opportunity to make a new chart with the ASP.NET Charting Control. I haven’t done much with this control yet, so this would be a good exercise.  The result of this exercise has already been embedded in my website.

With a Oregon Scientific temperature sensor placed on top of the thermostat that’s in the livingroom, i can also monitor the temperature near the thermostat very closely.  It would be nice to see what the heating is doing in relation to the temperature in the livingroom. Here it is:

Heating Temperatures

The Oregon sensor and thermostat sensor don’t always agree on the right temperature; most of the time the Oregon displays a value that’s 0.1 lower then that of the thermostat. That explains the average of 20.9 degrees in the upper chart. With the thermostat having a constant setpoint of 21 degrees (Celsius)  you can say it does a good job.

The temperature of the water that warms up our house, is much lower than i remember when we had an ‘on/off’ heating. Now the outgoing temperature barely comes above 45 degrees anymore. Looking at the behavior of the incoming and outgoing temperatures of the heating, you can see that the heating is still switched on and off quite a lot of times. Apparently it’s not cold enough yet to keep the heating burning for longer periods at it’s lowest energy level. Over dimensioned heating? 🙂 . I wonder what this will look like in the middle of the winter; the periods that the heating is constantly burning should get longer then.

Now all i have to do is add a flow-meter in the heating water circuit and i can calculate the amount of energy that is effectively pumped into our house…

To monitor the heating in a more convenient way, I’m going to create an extra page on my website soon with all the real-time details.

RBBB board tryout

Today i soldered a RBBB (Really Bare Bones Board) kit. This is an Arduino-compatible board, but much smaller than for instance the Duemilanove.

USB BUB powered RBBB running the Blink sketch

USB BUB powered RBBB running the Blink sketch

A few weeks ago i realized that if i were actually going to use an Arduino somewhere in my house, i would want the board to be much smaller then the Duemilanove is.
That’s when i found the RBBB at Modern Devices. I ordered 2 RBBB’s, a USB-BUB and a USB cable.

Putting all pieces together was pretty straightforward, the instructions were very clear and within an hour i had my first RBBB up and running it’s first sketch.

The dimensions of the RBBB are 15 x 76 mm, but you can make it even smaller if you can live without the power jack or even the voltage regulator.
Just cut a piece off of the right side of the board: 15 x 57 mm is the minimal board size.

Another thing i found out is that the ATMega microcontroller will run fine at 3.3V, which seems to be a better choice then 5V when you want to connect all kinds of sensors to it.
For that i will soon get me some JeeNodes which seem to be specifically designed for 3.3V.

One thing i’m still a bit worried about is what to choose for communication; 433, 868 MHz or XBee?
433 MHz is where i already have a lot of sensors transmitting; sometimes sensor signals are lost, which is not a big deal for things like temperature sensors, but if i want my ATMega to lock the front door, i don’t think 433 MHz is a good choice.
The same goes for 868 MHz: that’s the frequency on which all my security sensors are operating; i don’t want to over-populate that frequency either.
XBee module on 2.4 GHz then? Maybe.. but will i be able to reduce power consumption of ATMega + XBee to an acceptable level so that i won’t have to change batteries every week?  🙁 There’s still a lot of work to do…