Success with 1000-HDC

Following on from the last post, ComTexeStarter has successfully built an 1000-HDC and used it to flash to v3.01.

This picture sums it up very neatly:


I’d be very interested to hear from anyone else who tries this.


Firmware flash – success!

After having some very useful discussions with a few people (special thanks to ComTexeStarter) I came to the conclusion that there was nothing fundamentally wrong with my initial approach – ie using the FTDI board – and that the reason it hadn’t worked was down to software problems.

So I tried again today, the main difference being I was using a new laptop with a clean install of Windows 10. The driver for the serial port was automatically installed, and the Texecom firmware flasher picked it up as a ‘USB-COM’ cable as before. I took a deep breath, pressed ‘Flash’ and…

IMG_20160319_173540 - Copy

Success! Everything worked perfectly and the process was complete in about 3 minutes. Following this (as per the manual) I factory reset the panel by removing all power and then powering on whilst holding down the ‘Reset defaults’ button on the main panel PCB.

This caused a bit of a racket with the tamper alarms going off and you then have to enter the default code (1234). Once it settled down, I used Wintex to restore a backup of the configuration data taken a few days ago and the panel is back to normal. You also need to change the firmware version in the configuration screen so that it resets all the new settings to sensible defaults. If you don’t do this you can get some odd behaviour.

ComTexeStarter has been doing some great work on understanding what the programmer PCB does – and the answer seems to be, ‘not much’. Here is my (rather blurry) photo with their annotations (NB this is the correct version, I had previously posted an earlier one with different resistor numbering):


Most of the components and the chip seem to be concerned with feeding 12V to JP2 pin 1 which we think is used to power one of the older Texecom (non-USB) serial interfaces and so is redundant for the USB ones. This means that it should be possible to do the firmware flash with just the UART plus a few resistors to set the panel to programming mode.

ComTexeStarter has worked hard on this and has come up with this schematic which separates off the chip and the 12V supply (in the red box) from what is actually needed to do the programming:


Given that this is now a reverse engineered CDH-0001 this has been christened the 1000-HDC!

It’s quite obvious that Texecom have been churning these out for years (certainly since 2005 – date on the board) at a time when USB cables were rare or unavailable. They could almost certainly redesign their panel PCBs to support programming just from a USB cable which would be a lot cheaper and easier. Maybe they will do so in future.

The other thing I did whilst I had the panel open was install one of the new ComPort+ boards into the header pin sockets.


You can see it just under mains supply cable, plugged into the header with the (old) firmware version of LS1 v.211.09 on it. It is dead simple in construction:


At a quick glance the pin assignments appear to be (reading the pins from left to right when the board is installed – so pin 1 would be rightmost pin on the above picture:

Pin 1 – NC
Pin 2 – 12V
Pin 3 – GND
Pin 4 – NC
Pin 5 – NC
Pin 6 – NC
Pin 7 – NC
Pin 8 – NC
Pin 9 – RXD
Pin 10 – TXD

So if you don’t want to pay £7 for 5 of these boards (like I did!) and you want an additional serial port, I think you could just connect up your UART to pins 3, 9 and 10 directly. There are a couple of other components – the three pin SMD device is marked Z2X and is I think a Zener diode which is connected between to RXD, and has one leg grounded and the other not connected. The same track feeds goes to an SMD resistor (47k) and then to the 12V line. I don’t really know enough electronics to understand why this might be. However given the RXD pin appears isolated from 12V and connects directly to the header I suspect you could connect directly up to them without a problem. I’d be interested to hear if anyone tries it… meanwhile I have 4 more of these boards to get rid of so let me know if you’d be interested in one.

I haven’t tested Com3 yet but I have another UART on order to test it.

Exciting times!

Programmer details

As promised I’ve taken some close-up pictures of the programmer PCB. The chip is a MAX662A and the capacitors are connected to it as per the datasheet. I’m afraid that these aren’t great quality pics because I couldn’t get the light right, I will get some better ones and upload them in due course.

I’ve not done anything to try and work out a schematic or pins assignments as yet. However I am pretty sure that I was barking up the wrong tree with pin 1 on the serial connector. Whilst it does have 12V applied to it via the output from the 662 I don’t think that this is needed for the flasher to work.

I’ve had a useful discussion with someone who makes these cables up and it appears that the key thing you need to make them work is the FTDI chipset on the serial controller – which is presumably what the official cable uses.

I’m going to have another go at flashing the firmware at the weekend so will post the results.

Texecom Firmware Flash – Progress

After a brief detour into heating control I’m back to talking about my Texecom adventures. I will as promised come to the more detailed software side of the heating project soon. However, with the Spring weather coming I’m feeling keen to start taking on some new projects so I’m back to thinking about upgrading my Premier Elite to v3.01 (it’s already gone up from v3.00).

As some commenters have pointed out, one can buy the firmware flash interface from for a good price at the moment:


And they also are the only place anywhere that seems to be selling the ComPort+ accessory which gives you an additional serial port output using the on board communicator output.


These need more discussion and I’ll come to this in another post. As you will see I had to buy 5 of them… so if anyone wants one of my 4 spares for a nominal fee to cover costs please let me know.

Anyway I took the plunge and ordered them all, and they arrived last week. The service from cctvcentral was pretty good, as the firmware flasher got damaged in transit and they sent me out another very quickly.

I spent a couple of hours this afternoon with the firmware flasher, but unfortunately so far have met with failure.

I connected everything up as per the instructions, and I have learned a few things. First of all, this is the first time I had tried powering the whole panel down and one of the problems doing this is that it sets off the tamper alarm on the external siren. I have a Texecom Odyssey 1 which  I installed some time ago. It is quite smart for a bell box, and one of things you can do is temporarily disable it if you are working on it. You can do this by using the engineer utilities to switch the strobe on 3 times in 30 seconds. This worked quite well, although it resets itself when you put the power back on. I’ve come to the conclusion that it’s impossible to do any kind of work on alarms without making a dreadful racket.

I’ve also learned that the Texecom firmware software only recognises FTDI serial ports – presumably because that’s what is in the genuine product.

However, on running the software and trying to flash the panel… nothing happens. It just gives an error message saying ‘board not responding correctly’.

I’m a bit stumped by this – I’m sure that the pinout is the same for the serial port and the software recognises it. I’m quite sure that I’ve connected the ribbon cable to the alarm board properly.

The only difference between my home made cable the real one is the first pin – which on the board gives 12V out. Looking at the flash interface, the corresponding pin is linked to a couple of pins on the flash board including a capacitor or two. So it must be doing something… but what? I’m really not sure what I should do about this, as unless I can get hold of a real Texecom flash cable I can’t know what that pin is for.

So all in all, not good news at the moment. I have the flash board… but I can’t use it. And I really do not want to be spending £40 on a genuine Texecom cable after getting this far! I have seen people on ebay selling third party copies which they say do work with the interface, so I might have to resort to getting one of these. It seems a shame though… I’m sure the solution is pretty simple but at the moment I have no way of finding it out!

Any comments or thoughts would be welcome. I will post some hi res pics of the board (including the all-important underside) shortly.

Boiler Control using MAX hardware

So now I’ve got a number of MAX radiator valves around the house which are linked up to FHEM which is providing some monitoring and control. I’ll go into some more detail on the software side in another post. However, I realised that the amount of value that you get out of this system is pretty limited unless you can find a way of controlling the boiler.

Most of the other systems like this which I have seen do have some form of relay or control (sometimes called a ‘boiler interlock’) so that the individual zones can ‘call for hear’ and similarly the boiler shuts off automatically when heat isn’t required. Without this all you have is some fancy valves but the boiler control is still only by a basic thermostat or timer.

Unfortunately, there is nothing available in the MAX range which does this. This seems to me a major omission as all the others do (FHT, HomeMatic, evoHome etc). I had a bit of a problem, as I needed to be able to address the relay via FHEM on the computer, but the CUL device can only be used in one mode at a time. So if I wanted to use a relay from a different system (eg HomeMatic) I would need to have a second device to do so which will obviously cost a lot more.

I thought about this a lot because I really didn’t want to spend a lot of money on this and I didn’t want to overcomplicate matters. After a bit of digging around I found this:


This is one of the MAX products (details here ) although it is a little obscure. To be honest I’m struggling to work out when exactly anyone would use. It is basically a switched mains plug just like many which you find in home automation systems. However it is designed to work as part of a MAX system. So far as I can make out from the documentation it is supposed to be used with electric heaters or pumps that plug in to the wall. I’ve never seen anything quite like that… but maybe they have them in Germany.

The good news is that because it is a MAX device I can address it from FHEM without using any additional devices. However it wasn’t immediately obvious how I would use it to switch my boiler directly, which used a 240V switched circuit which normally goes to the thermostat. I had a few ideas, including stripping the whole unit down and somehow wiring the relay in directly and whilst I did get the board out to have a look there was no obvious way of doing this. The fact that it uses a European plug (aka Schuko) is another obstacle.

So I considered a few options, including buying a Schuko socket to plug it into. However as above I was trying to keep the costs down and keep it simple. My boiler already has main supply to the existing thermostat receiver so it’s fairly easy to wire things in. So what I have ended up with is starting with a UK socket, then an adaptor, then the switch unit, and then an older shaver plug with a flying lead.

The other end of the lead goes to a huge and rather OTT mains relay which I got for a few pounds from ebay:


Luckily it fits quite nicely into a blanked off single switch box, with the wires poked in through a hole in the bottom and fixed to the screw terminals on the base. The output from the flying lead on the switch goes to energise the coil, and the output contacts are wired to the thermostat input. So I’m using a mains relay to switch a relay to switch the boiler on! It’s a bit convoluted… but it works!

The end result in the boiler cupboard looks like this:


So a little inelegant perhaps… but I’m happy with the result.

In FHEM it can be configured as a MAX thermostat (so it appears exactly the same as one of the radiators) but it can be switched on and off by sending an ‘on’ or ‘off’ command to it.

I’ll cover the FHEM configuration in a bit more detail in the next post

Moving to MAX!

When I moved house I started to look at expanding the heating control system, especially given that the new house was much colder than the old one. I started by looking at the FS20 kit I already had, but it was looking really expensive being around £70 per room. On top of that, I was unfortunate in that every radiator in the new house had Vaillant TRVs which are a non-standard fitting and so I’d need an adaptor for each as well.

I was pleased to stumble upon Andy Carter’s blog in which he has gone on a very similar journey, and this introduced me to the MAX! range of products (German language link but but Chrome translates it pretty well). These are produced by a German company called eQ-3 who make a whole range of home automation products. There seem to be two ranges – MAX! and HomeMatic. MAX appears to be a more budget model and is restricted to heating control. HomeMatic is a bit smarter and has a much wider range of modules for all sorts of things including relays, sensors etc but it also has the equivalent of the heating control as well.

The basic system consists of a replacement TRV head and an optional wall controller which directly associated with it. There are now three different types of these although the differences between them are pretty minor.

The big plus for me was that (unless you wanted the wall control) these were a single unit rather than two, and such were substantially cheaper (£25 all in). This made it much more viable to buy in a significant number of them, and in a number of ways they were better than the FS20 units. I liked the large backlit displays and the ease of controlling them, and it was clear that they were also well supported in software. Best of all, the CUL dongle can be used to speak the MAX protocol and so I didn’t need to buy the MAX cube controller.

As I started to put them I learned a few things:

There are various different types of TRV fitting depending on manufacturer. The MAX heads come with various adaptors for the most common ones, and will screw directly on to others. I have ended up standardising on Danfoss valves in the house, for no really good reason except that they are good quality and look nice. The supplied adaptor does work although it a bit of a pig to fit. You get this set of adaptors each time:

The Danfoss one is the far right. You have to remove the bolt, and snap the collar around the valve mechanism. Then you tighten the bolt and screw the valve itself on. Once this is done it seems to work well and is a tight fit. However, I’ve decided that in future I’ll buy valve bodies that don’t need an adaptor at all as this is much easier.

The second thing is that in the UK normal TRVs seem to generally fitted vertically. This does appear to be a matter of convention, although I have read that it makes more sense for them to be mounted horizontally instead because it moves the body of the valve away from the radiator itself and means that the airflow is more representative of the temperature in the room. Also, the MAX valve are obviously designed to be mounted the same way, as if you do mount them vertically the display is upside down. So on all my new radiators I’ve asked the plumber to fit the valves horizontally and they look much better this way. It is easier to read the display and to operate the valves. However I do have some on old valves which are upside down for the time being. It doesn’t seem to affect the way they work, fortunately.

The third thing I’ve found is that installing these valves on their own doesn’t really get you very far! I’ve had quite a few of them in the house, but I don’t think you get very much benefit until you find a way to interlock what the valves are doing with the boiler. This unfortunately is easier said than done… but I have found a way to be described in the next post.

Intelligent Heating Control – First Steps

As promised I’m now turning my attention to a different project. For a long time I have wanted to handle control of my heating system much more intelligently than just relying on a single thermostat. My house is a fairly large Victorian terrace spread over three floors, and the rooms are large with high ceilings. At the moment the thermostat is in the hall, and this is supposed to take account of the heat in all the rooms of the whole house. It seems a very blunt instrument and I’m sure I’m wasting a lot of heat.

This sort of thing is topical and there have been products such as the much-vaunted Nest thermostat. However, I’m really unimpressed with this – because no matter how fancy it is it only samples heat from one place. If you live in a small flat then that’s fine – but it doesn’t help my situation.

As well as having more sampling points, you should also have more control over how the heat is distributed. Nest etc only control whether the boiler / heat source is on or off – not where the heat is going. My house uses standard gas-fired heating with radiators and thermostatic radiator valves (TRVs) but I’ve never been very satisfied with these. Also of course they don’t provide any control of the boiler.

It seems I’m not alone in this – there are a small number of products out there which address this issue, and the most recent and most consumer friendly is the Honeywell EvoHome system.


This does look very interesting but I’m not pursuing it for various reasons (mostly because I don’t want to have to start again with a new system). There does seem to be a lot of discussion about it in the AutomatedHome forum

The basic idea is that you have one or more replacement TRVs which are motorised and have a temperature sensor. The valves report back their temperature to a central control point, which is then able to control the boiler to switch on as the need to heat each radiator arises. This feedback is the big plus over a normal TRV (which really only regulate maximum heat) as it allows them to regulate minimum heat too. When heat is called for, only the radiators which need it will be on and so the heat is much more efficiently transferred to where it is needed.

I’ve been looking at these systems for quite a few years now. When I first started about 5 years ago, the only thing out there was the FHT range. This is based on the FS20 protocol, which seems to be very well-established in Europe and particularly Germany. There is an enormous range of FS20 kit available, far more than any equivalent system used in the UK. However, it seems little known about here. The FHT system involved a separate valve motor (FHT 8V) and room thermostat. The motor adjusted the valve depending on the temperature, and a separate boiler interlock (FHT 8W) which listened to the settings of the valve motors, and when they reached a certain level it triggered the boiler. The FHT 8W is a remarkably overengineered piece of kit – I bought one at great expense (about £80) but I don’t think many other people in the UK did.


I had this system (two or three thermostats and the boiler switch) in my old house which was much smaller, and it did seem to work quite well. I discussed this quite a bit at the time on various forums and blogs (see discussion with Jack Kelly who goes into the whole subject in some detail). However, when I moved house the FHT kit remained very expensive and I rather lost interest in the whole idea as other more pressing work took over.

The other thing which I did get from my first attempt was computer control of the system. I was not satisfied with just the kit, I wanted to monitor and control it much more closely. Once again, I found that the Germans were very far ahead of us. Through reading various forums (thank goodness for Google Translate) I learned about FHEM. This is very mature and well established home automation control system. I’ve been following home automation for years (and I have a developing Z-Wave system for lights etc which I’ll talk about some other time) and am aware of various software systems.

However FHEM stands out for a number of reasons – it is unashamedly geeky and flexible (hence it suits me well), it is extremely well supported (if you speak German) and has support for the widest number of different systems that I’ve ever seen. To get it to talk to the FS20 system I needed a CUL1101 device. At the time I got mine the only place you could get them was from busware which is another German company. It was rather expensive (about 50 Euros although they are more now) but gave me what I needed to interface FHT with FHEM and read out the data to plot some graphs. However I never got much beyond this and I was aware I hadn’t really made the most of it.

This is pretty much where I got up to before I picked it up again recently – which I’ll cover in the next post.