Having had some success in building a DIY equivalent to the USB-COM cable, I started to think about the COM-IP controller. Texecom sell this at great expense. It provides an Ethernet interface from the panel, which allows you to configure the panel over the network rather than having to connect directly to the panel. It also allows you to connect other things in to the panel to provide remote control or get status information from it. The first problem is the price. CTS-Direct have it for just over £90 plus delivery and this seems to be about right. Numerous other retailers have it for the same price although there are some second hand deals on ebay which are a bit better. However this still costs more than the panel did which seems a bit much for such a tiny device: I have been investigating linking the panel up with other home automation kit (more later) and someone suggested to me that you could use ser2net running on a Raspberry Pi or similar in conjunction with the USB serial connection I already had in order to give the same results. First thing was to see what the serial connection is actually doing, and establish what the parameters for the serial connection are. I used a serial port sniffer to identify this. I tried a few but eventually found ‘Free Device Monitoring Studio‘ which is massive overkill, but does provide the basic functions needed. I ran this whilst connecting to the panel with Wintex. I was hoping to see some comprehensible data but in fact it is clearly encoded. However, I was able to get the serial parameters out which are:

19200 baud, 8 data bits, no parity, 2 stop bits

This is the first time I have ever seen a serial link which uses 2 stop bits – so maybe this is a sneaky trick by Texecom to get you to buy their product. If so then it is fairly easy to get around. The next thing to do is to set up ser2net. It forms part of most Linux repositories, and the Raspberry Pi is no exception. I’ve started with a fairly basic and clean install, booting to the command line. Then I have installed ser2net like so:

apt-get install ser2net

Then plug in the serial cable and it should be recognised and appear as a serial device. You can use the ‘dmesg’ command in Linux to check. I’m using a FTDI 232R device:

[166583.359561] usb 5-1: new full-speed USB device number 2 using ohci-pci
[166583.821660] usb 5-1: New USB device found, idVendor=0403, idProduct=6001
[166583.821673] usb 5-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[166583.821680] usb 5-1: Product: FT232R USB UART
[166583.821685] usb 5-1: Manufacturer: FTDI
[166583.821690] usb 5-1: SerialNumber: A9C3JDH1
[166583.927074] usbcore: registered new interface driver usbserial
[166583.927109] usbcore: registered new interface driver usbserial_generic
[166583.927136] usbserial: USB Serial support registered for generic
[166583.936455] usbcore: registered new interface driver ftdi_sio
[166583.936482] usbserial: USB Serial support registered for FTDI USB Serial Device
[166583.936601] ftdi_sio 5-1:1.0: FTDI USB Serial Device converter detected
[166583.936658] usb 5-1: Detected FT232RL
[166583.936662] usb 5-1: Number of endpoints 2
[166583.936665] usb 5-1: Endpoint 1 MaxPacketSize 64
[166583.936669] usb 5-1: Endpoint 2 MaxPacketSize 64
[166583.936672] usb 5-1: Setting MaxPacketSize 64
[166583.939669] usb 5-1: FTDI USB Serial Device converter now attached to ttyUSB0

The next step is to set up ser2net to connect to the USB serial port and convert it to network frames. This is done by putting a line in the configuration file – held in /etc/ser2net.conf. I’ve used this line:

10001:raw:0:/dev/ttyUSB0:19200 8DATABITS NONE 2STOPBITS

‘10001’ is the port number (used later); ‘raw’ means that there is no further processing of the frames; ‘/dev/ttyUSB0’ is the name of the serial device as above; the rest of the line contains the serial parameters we found above. Restart ser2net to re-read the config file, and then you will have in effect a working equivalent of the COM-IP. To make use of it you will need to IP address of the server running ser2net and the port number as above. The most obvious use of this is to use Wintex (the Texecom configuration tool) over the network. Configuring this is the same as for the genuine COM-IP although it is a little obscure. You need to go into ‘Edit Account’ in Wintex: And then select the ‘Panel Details’ tab: It’s hidden away in the bottom right hand corner under ‘Network Details’ – here you need to enter the IP address of the server, and the port configured in ser2net. Once you’ve done this, you can connect to the panel using the ‘Connect’ button in the Wintex main screen and proceed as normal. So far as I can tell this approach exactly replicates the function of the real COM-IP but at a fraction of the price, or indeed free if you already have a Raspberry Pi or a server lying around. There are some other interesting ideas for making use of this which I’ll come to in future posts.

One of the things which really attracted me to the Texecom panels was the ability to interface them directly with the computer – and other things (to be described in a future post). However, in order to do this you need to buy a fairly expensive cable from Texecom – the COM-USB:

Texecom COM-USB

These seem to retail for about £40, although there are some cheaper 3rd party versions on ebay for rather less, which seem to do exactly the same job:

However even this seems a bit steep for what looks a fairly simply USB cable, and the pins on the Premier Elite main board also appear fairly standard.

I then came across this extremely helpful post:

Programming a Texecom Premier Elite 12-W using a FTDI cable

In which the author has discovered that the connector on the board is no more than a straightforward serial connection, with three pins – TXD, RXD and GND – connected. Using a USB-serial converter he was able to get everything working with the official ‘Wintex’ software which is a free download from Texecom.

I took a slightly different approach and bought from ebay a very small board which converts a mini-USB plug into serial with pins and solder points as outputs. It was about £4 delivered.

I then used an old motherboard header cable directly soldered to the TXD, RXD and GND points on the board above, and connected the other end to pins 3 (GND), 4 (TXD) and 5 (RXD) at the Texecom end. So in other words the data is received by the Texecom on pin 4, and transmitted from pin 5. Once this was all wired up I secured the board inside the casing with a cable tie and ran a USB lead outside the box.

The end result looks like this:

So a very cheap solution which is just as good as the £40 official alternative.

An early opportunity to relearn the important principle of reading the manual.

I had installed one of the zones using a smoke detector, again a straight replacement for the old one. The manual said that it used a ‘normally closed’ relay which opened in an alarm or fault condition. So I wired it up (like the other sensors) to the alarm terminals.

For each zone there are two pairs of terminals – two marked ‘A’ for alarm sensing, and two marked ‘T’ for tamper returns. I had wired the detector up to the ‘A’ terminals, thinking ‘it’s a smoke alarm… why would it need a tamper circuit’. Also of course there are no tamper detectors in the smoke alarm anyway.

Cue a load of headscratching, as however I configured the detector in the software it always returned an alarm condition (it comes up as ‘active’). This is an issue because it stops the alarm setting and all I could do to start with was exclude it completely.

Eventually after a lot of searching I found a reference somewhere to using the ‘T’ terminal and this prompted me, finally, to read the manual. I found this:

D’oh!

One change of terminal later, and now everything works fine.

Life’s lessons learned once again

I’ve just upgraded the alarm system in my house. When we moved in several years ago there was an ancient ADT installed alarm system. This had been monitored by phone, but when we came we pulled out a lot of the wiring and more to the point didn’t want to pay any monitoring charges.

The system has been rather temperamental since then, and I’ve been keen to change it ever since. The reason for doing so is that I’ve wanted something more reliable and higher tech… and also I’m intrigued by the possibilties for tinkering that this offers.

I did quite a lot of research, and I ended up choosing a Texecom system. This seems to be a cut above the normal domestic brands and are clearly used in a lot of professional settings. I wanted to reuse as much of the existing wired infrastructure as possible, and so I needed at least 6 wired zones. I also wanted to option of using a wireless expansion for extra zones, plus as much options for connectivity as possible. I decided to replace all the sensors as well with modern equivalents.

I bought the following:

Texecom Premier Elite 48

Texecom Premier Elite LCDLP keypad

I was surprised how cheap they were – about £90 each. The keypad has a big display, and support proximity tags as well as some zone expansion. The keypads come in all shapes and sizes – you can get brass, metal, chrome and plastic versions, include a range which can be sunk into the wall. I ended up picking the plastic one because it was cheaper and I’m not quite ready to bash big holes in the wall.

Installation was pretty easy – just a question of stripping the old box out and rewiring the old zones to the new ones. Then the fun begins…