Geek

Heating control

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Recently I mentioned monitoring the house with wireless sensors dotted around the place. It uses node-red to average the temperatures, and come up with a synthetic value that gets reported back to the home control system, Domoticz.

Next stage is to control the heating.

The heating system in my house is a very old design, and there’s simply a plug for the heating pump, and a plug for the boiler. When the heating is commanded to turn on by the control device (so old it’s not even a thermostat) downstairs, it really just connects these two plugs to a mains supply. The boiler and pump then turns on, and warmth ensues.

My chosen method of automation is simply to keep the heating ‘on’ all the time, and have some sort of device plugged in to the plugs in order to turn them on and off remotely. I want this to be completely retrofittable, so we can remove or change it at a later date without massive amounts of rewiring.

My initial thought was just to use a couple of LightwaveRF appliance modules, but I had a USB controlled dual relay floating around that I long planned to control the TV with, but never quite managed to get around to. Additionally, and conveniently, up the loft there’s a laptop that I use for transcoding the satellite feed to IPTV (with TVHeadend), so it was a simple case of hooking the USB board up to that laptop and getting some software on to it.

Also, to make it a bit safer, and along with the retrofitting feature, I opted to put the relay board into a little dual gang enclosure, and wire in some 13A sockets that I had in the garage.

The end result is a little deamon called mqtt-usb-relay that sits and listens for MQTT messages and then act upon them to turn the USB connected relays on and off. It subscribes to the /raw/`hostname -f`/usb-relay/#, topic, and simply takes the last component of the topic as the relay number to control, and the message as the state to turn the relay to.

Now, doing this ‘correctly’ would involve parsing the JSON output of the 3rd party mqtt.js script for Domoticz, but I decided to keep things simple and to use the On and Off Actions built into Domoticz to trigger simple mosquitto_pub events.

To do this, just create the dummy switch in Domoticz, and in the On/Off Action field, stick in commands similar to this.

script://///usr/bin/mosquitto_pub -h mqtt.vpn.glasgownet.com -t /raw/wmlp1000.vpn.glasgownet.com/usb-relay/1 -m 1

Job done. The heating can now be controlled from Domoticz. It’s not extensive control over zones or power levels of the boiler (although I have an idea for that), but it can certainly command the ‘MORE HEAT’ desire, and maybe one day I’ll install wireless TRVs on the radiators.

ESP8266 Links

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What with the recent buzz around the latest ESP8266 chips, I thought I should compile a list of handy links here…

The manufacturer of ESP8266 – http://espressif.com/
Manufacturer discussion forum – http://bbs.espressif.com/

Community forum – http://www.esp8266.com/
Lua based firmware – http://nodemcu.com/index_en.html
Discussion regarding MQTT on the ESP8266 – https://groups.google.com/forum/#!topic/mqtt/Uy985KUpG64
ESP8266 Github wiki – https://github.com/esp8266/esp8266-wiki/wiki
Working GCC Toolchain – https://github.com/esp8266/esp8266-wiki/wiki/Toolchain
Open source SDK – https://github.com/pfalcon/esp-open-sdk
Native DHT22 and LED I/O using Lua – http://harizanov.com/2014/11/esp8266-powered-web-server-led-control-dht22-temperaturehumidity-sensor-reading/

Buy one (UK) – http://www.amazon.co.uk/gp/product/B00O9DSZBA/?tag=thelod-21

Avaya 4621SW Config by DHCP

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I’ve been fiddling with an Avaya 4621SW IP phone recently, and I wondered if it would be more appropriate to pass settings to it via DHCP options, rather than editing the 46xxsettings.txt file that it always downloads via TFTP.

Previously I had the following in my 46xxsettings.txt file

SET SIPDOMAIN glasgownet.com
SET SIPPROXYSRVR voip.vpn.glasgownet.com
SET SNTPSRVR pool.ntp.org

In an effort to transition this to DHCP, after a few minutes of experimenting this was the final outcome that went in to the top of my Debian dhcpd.conf file. It handles the Option 176 that Avaya phones use to get parameters passed to them.

option space Avaya;
site-option-space “Avaya”;
option Avaya.custom code 176 = string;
option Avaya.custom “SNTPSRVR=pool.ntp.org,SIPPROXYSRVR=voip.vpn.glasgownet.com,SIPDOMAIN=glasgownet.com”;

The last line there contains my SIP server settings as I’m using the SIP software stack on the phone. Equally, I’ve tested the following with the H323 firmware, and it works too

option Avaya.custom “MCIPADD=8.8.8.8,MCPORT=1719,TFTPSRVR=172.24.32.1,L2Q=1,L2QVLAN=10”;

Now, http://www.voip-info.org/wiki/view/Avaya+4602+configuration states that the 4602s can be configured independently by manipulating sip_.txt, but I’ve yet to see any requests for those files. Worst case scenario is that I embed SIP_USERNAME1 and SIP_PASSWORD1 into option 176 for each client. Nasty…

MQTT to Zabbix Gateway

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For a while now I’ve been wanting to try and monitor home automation parameters by using Zabbix. I already use it to monitor, graph and alert on servers and services at work and at home, so it was a logical extension to use it for home automation. I hope to deploy TinyTX sensors around the house, and by using my mqtt-rfm12b gateway I *should* be able monitor and alert on their battery voltages when things start to run a bit low. Firstly though, something is required to push the data from MQTT to Zabbix.

The first thing that you’ll need is a working Zabbix instance. This is somewhat outside the scope of this blog post, and the documentation is fairly good. You’ll need a host configured, so add one and give it a name, or alternatively use localhost that I think Zabbix comes preconfigured with.

Clone my mqtt-zabbix repository, and you’ll find a XML Zabbix template that can be imported into your Zabbix install (import via Configuration -> Templates). It won’t do anything drastic other than 10 or so Zabbix keys.

Once the import is completed, Configuration -> Templates will contain a template called “Template App MQTT”. This has the 10 items, all of which can be edited to suit. The important part is the “Key” – which must match what you put in the keys.csv later on. Simply put, when Zabbix receives data with a specific key, it gets stored against the item with that key defined. It’s not terribly complicated :-)

If you’re happy with Zabbix and the template import, follow the mqtt-zabbix README to get the rest of it installed. It’s really just a glorified script with some init scripts. Put all the files in the right places, edit keys.csv to match between your MQTT topic and your Zabbix key name, and start the application.

mqtt-zabbix subscribes to the root wildcard topic at /# so possibly isn’t very efficient on systems with massive amounts of traffic, but for home use it’s quite sufficient. I may change this method of working at a later date. In the meantime, the moment something arrives at your topic it will be forwarded on to Zabbix. A log of the event will also be found at  /var/log/mqtt-zabbix.log and it will tell you if the key was successfully inserted or not.

To view your data in Zabbix, click on the host, click on Latest Data, and it should be listed under – Other -. You can then choose the graph option on the right, or you can edit your own custom graphs and include the MQTT items.

Updating Optiboot & CC3000 Firmware with an Arduino

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Optiboot flashing in progress

I recently purchased a CC3000 wireless board to play with on Arduinos, with an aim to use it on an Arduino Mini Pro to control some LED lighting I have. Rather than purchasing through Adafruit as I possibly should have done, it was ordered through Ebay. This turned it into a bit of a learning experience!

The Adafruit library does a firmware check to ensure it’s the most recent version that they ship, however the version I purchased from Ebay was of a lower version, and subsequently the Adafruit library would refuse to run tests. Although this could be tweaked in the code, I didn’t fancy making that change and would rather have hardware with at least a firmware version equal to or higher than the one that Adafruit use. Onwards to updating the firmware of the CC3000!

If you were following Texas Instruments guide you’d be using one of their products to do the update. With only Arduinos to hand, I ended up trying out CC3000Patch sketch from Chris Magagna.

Firstly, two things should be noted about CC3000Patch

  1. It requires almost all of your flash space
  2. It needs newlines on the serial input

The flash space isn’t really an issue until you consider that both older versions of the Arduino bootloader and older versions of Optiboot will take up too much space. I was unable to flash CC3000Patch onto an Atmega328 with Optiboot from around January 2012, so I subsequently had to look at updating Optiboot before going any further.

I was using two Mini Pros to do the programming, and although the guides don’t really cover programming these the process is broadly similar. Hook up MOSI, MISO, SCK, IRQ, Reset, Power and some status LEDs, and then flash ArduinoISP to the host Arduino *before* connecting the target Arduino. I’d also highly recommend hooking up heartbeat, error and programming status LEDs to pins 7, 8 and 9 so that you can see what’s going on. Once you’re happy with that it’s flashed ArduinoISP correctly, and the heartbeat LED is pulsing quietly, *disconnect* the DTR line between your serial adaptor and the programming Arduino. This will prevent it from autoresetting just before the upload is triggered.

Next stage, plug in the target Arduino, and run “Burn Bootloader” from the Arduino IDE (I used 1.0.5). The *target* Arduino will reset, and programming LED on the programming Arduino will light up for a minute or so. Once it goes out, all should be good.

CC3000 being flashed

Optiboot on the Mini Pro, and time to try CC3000Patch again.

First off, make sure you wire up the connections correctly. It’s wise to use the Adafruit buildtest sketch at this point to make sure you have communication with the CC3000. If the firmware version is correct, it will tell you that… if it’s incorrect, it will also tell you that :-) The good thing is that you have communication with the CC3000 at this point, and you can move on to updating the firmware.

The documentation for CC3000Patch is fairly good, and all you need to do is compile and upload the sketch to the Arduino, and then follow the documentation. However, if like me you use screen to communicate over serial, you’ll need to use control characters to send newlines to the Arduino before it will start listening to your commands. ^V^J (that’s Control+v, Control+j) are your friends, and you’ll be driving the text menus in no time. I believe the Arduino IDE has a similar setting somewhere in the serial monitor window, although I’ve never used that feature.

All being well the CC3000 will be quietly upgraded to v1.24 (or later), and buildtest from Adafruit_CC3000_Library will then tell you what version of firmware you have. Handy hint also… the SSID is case sensitive :-)

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