WebIOPi Irrigation System

A garden irrigation management kit based on a Raspberry Pi and a standard PiFace interface card

After the tutorial series, I’m please to announce the first official Irrigation System WebIOPi-based application. It can work with PiFace, IO PI, or any I/O expander supported by WebIOPi.

The system provides both manual and automatic mode, with a week schedule to activate each station in sequence for a given duration. Even for people who don’t have an irrigation system, it’s a very nice application to go more further with WebIOPi. On my side, it pointed me few issues and difficulties can encounter people when using the framework, so I can improve it.

[From WebIOPi Irrigation System | trouch.com]

Air Quality egg – making sense of the CO sensor

To sum up :

The air quality egg outputs 2 values per sensor – the raw resistance measured, and a interpretation of that based on a number of factors including a average calibration value (R0), humidity, temperature and a factory supplied set of graphs helping to turn the raw resistance value into a ppb (Parts per billion) value for human consumption.

So these are the values from our AQE (Now placed outside in a semi rural placing)


and these are the values from another AQE in the UK (also placed outside in a rural setting)


and as you can see – the raw resistance is not that far apart taken over time, but the interpreted values are extremely far apart.

I would expect both of these to show very small CO values, and there is clearly something wrong in the delta between the 2 interpreted graphs.

I suspect mine is wrong – as the values are way too high, especially seeing it’s windy outside, and the air “feels” good to me.

The manufactures of the AQE has a blog posting about how to set the R0 (or calibration resistance) of the egg to change the calculations – so that is one way of correcting the interpreted values, but it is a bit cumbersome, as it requires you to upload new software to the Arduino clone, running it, and the re-uploading the base station software. For experimentation this seems a bit long winded.

What I feel is needed is software to do this on my own computer – so I may have to sit down and get cracking on this – after all this is the real advantage of all the open source software!

Smoking hot kamado barbeque

Yesterday I tried dipping my toes into the world of food smoking using the newly aquired Kamado bbq.

I started with chicken breasts – at around 120 degrees celsius for 3 hours.


So far so good – the chicken actually tasted very, very good (or at least I thought so – as the rest of the family are vegetarians I had no-one to be secondary taster (-; ).

BBQ smoking

Our old barbeque (a gas one a few year old) is already showing lots of rust and signs of falling apart – so earlier this year we started looking around for something slightly more robust.

And we came across a “new” breed of barbeques – the “kamados” – named (apparently) after Japanese indoor fireplaces.

And as these are hard to get in the UK we settled at the only one we could find – a “Kamado Joe”. These are made of thick ceramic, and looks strangely like a world war 2 mine – less the explosives.


(Click for larger image)

These are supposed to do quite a bit more than a traditional barbeque, as they can smoke food, and also be used to bake food. All this due to the rather interesting way of being able to control the heat inside the dome by controlling airflow through the 2 airvents.

The one at the top looks like this :


The theory being that by controlling the amount of oxygen that the coals can get hold of you can control the temperature.

And today I’m trying out this on chicken breasts – where the temperature should be kept around the 120 C – something I’ve not quite managed to master so far, even using the extra “heat deflector” sitting under the grilling surface.

But practice (should) make perfect – so if the weather stays like this i should be a expert when summer arrives.

Barbecue Lodge – I want one

As we are looking at doing some buildingwork on the house I have looked for outbuildings on the web – and came across these barbecue lodges – which may just fit into our garden….

Used in the Arctic by reindeer herders for hundreds of years, these arctic barbecue huts are ideal for any weather – chilly summer evenings or snowy winter days.

Perfect for year-round use, these stunning bbq huts (called Kota in Finland and Grillhouse in America) come in a variety of sizes, the Hare (perfect for cosy romantic gatherings or dinner parties) the Fox which is an excellent lodge for all the family to enjoy, (sleeps three and seats 15 people), to the Reindeer which can comfortably seat 28 for larger functions or wilder parties!


(Click for larger)

[From Traditional Barbecue Lodges made in the UK]

Weather station

My main Christmas gift from the family was a Weather station – and decent Mac software for it.

So this is currently online from a few places on the Internet, and of course available from a webpage inside the house (and on my chumby)

The Lightsoft Weather Centre – or LWC as it’s affectionately known is the key to getting this up and running on a Mac under OsX, and it looks like this :


(Click for larger image)

and it’s superbly customisable, even down to making quite bespoke webpages available – but more about this later.

And best of all – it fits into the home monitoring/automation system I’m building based on the Arduino, where I can pull both internal and external data together from measurement points all over the house and the weather station as well.

The weather station itself is a WS2355, originally from LaCrosse, but now from other suppliers as well as a more generic weather station. It comes with a USB interface to the central console, which in turn uses wireless signals to pull in measurements from external sensors, in this case for humidity, temperature, windspeed, wind direction and rainfall.

The measurements are then stored in a LWC database for display of historical data.