…and balls, and squares, and hearts, and stars! If you want to build your own amazing MQTT enabled duck, I spotted these LED lights in Homebase at the weekend which might be worth a try at £2.50 each:
The hardware side of my ambient orb project is almost finished, so I’ve been making a start at the other end: getting some data to display. Top of my wish list is to display a basic weather forecast on the orbs, which looks like it could be nice and simple thanks to the very handy Weather Underground service. There’s a decent weather station nearby for current readings, and the forecast for Southampton has been pretty accurate so far, both of which are available through the Weather Underground API.
I could process the resulting XML on my home server but, having been doing some work with mashups recently, I thought I’d create a feed mashup instead. I’ve played with Yahoo Pipes in the past but this time I created a feed using Mashup Hub on Lotus Greenhouse:
So that screen shot is probably not all that helpful in understanding what’s going on; this style of graphical programming is fairly common these days but I would personally like to see more advanced ways to document and share diagrams like this. Still, this one is pretty simple, so here’s a quick overview:
- The path at the top extracts the current temperature from the local weather station data
- The middle path makes use of some very handy date functions in Mashup Hub to pick out entries 12 hours ahead from the forecast data
- The bottom path does a lookup on the forecast conditions to replace a text forecast with a numeric code
Which all ends up being published as a much simpler piece of XML. I could just grab this XML directly and process it on the Arduino, or I could save some effort and convert the mashed up XML to an even simpler comma separated list using an XML to CSV converter written for the Pachube community. Well, now it would be trivial to create a Pachube feed for the weather forecast as well… so here it is…
Perhaps not the most direct route for getting a weather forecast but I think it’s a nice example of how anyone can pull together data they are interested in without any programming, or a server of their own. I’m also quite please with the results of the forecasts so far; 13 C and clear tomorrow in theory!
Well, the polar bears have begun their migration back north to the loft. It was my first experiment with an ambient device and the Christmas tree was certainly hard to ignore, especially when Jo complained the bears had gone off again! As a result, I updated the arduino sketch a bit to just briefly flash the bears off every three minutes when our energy use was high instead of turning them off completely. Still annoying apparently (kind of the point!) but the bears did manage to stay under arduino control all Christmas with only a few breaks on manual! A few observations now that the experiment is over:
- I don’t think having a display like CurrentCost’s in the house makes a huge difference after the initial discovery phase. That’s not to say that the display is pointless: it is much easier than checking the meter, and the cost estimate is great, but after I found out what wastes the most energy, I rarely look at it. Is that the same for most people?
- On the other hand, having a Christmas tree flashing when a lot of energy is being used is much harder to ignore! Not really an all year round solution but I’m sold on the idea of ambient devices. I hope to have a more compact one soon. It would be nice to have a simple indication near the front door as well for quick checks that everything is off before going out.
- Energy use alone wasn’t enough information to tell whether the house was occupied or not. I had planned to leave the lights on automatic all the time, so they would turn on when we arrived home and off when we were out. A daft idea with hind sight because the fridge and central heating were enough to confuse the poor polar bears.
- The arduino does a great job controlling Home Easy devices. I had it set up to send ‘reminders’ on a regular basis, which seems like a good way to make sure things are in the right state without any acknowledgements from the Home Easy receivers. (Also quite entertaining when the lights pop back on after someone turns them off with the normal Home Easy remote! I’m easily amused!)
- This was the first project I ‘completed’ with the the arduino, and it was almost useful! Well, I enjoyed it at least, and it’s got me thinking more about the next project: the ambient orbs if Farnell ever ship the TLC5940 I ordered, or a wireless programmable thermostat.
It’s not quite the sort of do it yourself which B&Q is traditionally known for but ‘Lights by B&Q‘ is looking like a perfect ambient orb kit. I almost managed to resist getting one while buying paint for the bathroom, but it just looked too tempting…
Getting inside was easy, with just a few screws holding the back in place. Once in, there’s a simple string of little circuit boards glued to plastic balls. A bit of levering popped the first one off to reveal a set of three LEDs, and it looks like they’re soldered on in a common anode arrangement…
You could just ditch the RGB circuits completely and pop in a few blinkms but I’d like to reuse what’s already in B&Q’s handy kit. I think it should be possible to cut the tracks to the colour changing circuit and wire the LEDs up to an Arduino instead. The problem is that there aren’t enough PWM outputs on a single Arduino to drive three RGB orbs. Fortunately a combination of a TLC5940 LED driver chip, and the Arduino library to go with it, should solve that problem.
Here are a few other links which look like they could be useful for this little project:
- Instructables RGB LED tutorial
- DIY Ambient Orb
- Arduino Orb Build Warden
- Hue-controllable RGB LED lamp
If I get the simple version working, I’d eventually like to get it working wirelessly. It would be much more useful if the orbs could be plugged in anywhere in the house rather than being connected to my home server via USB the whole time.
Update: not to be outdone, it looks like Homebase have a selection of (far cheaper) ambient orb kits as well now! (23 August 2010)
I was only in B&Q to buy some paint, but spotted this on a slightly scenic route to the paint aisle…
I almost had enough will power not to buy it but it was too tempting. It’s just too perfect for some hacking; 1 arduino + 1 B&Q LED disco lamp = 3 ambient orbs I’m thinking. The back even has four screws for easy access… which I’m not going to touch until after painting the bathroom, getting married and having a honeymoon!