How to build an outdoor cinema screen in your garden.
My flat has a small backgarden which I thought could make a great outdoor cinema (as you do). So if you’re thinking of doing something similar, here’s how it’s done!
First thing you need is a garden.
Square tubing for the frame which I found on a website that produces modular furniture units.
A good saw.
A mitre to cut the piping at right angles.
The best bit about this modular system is that it comes with a handy joining units.
Just bang the appropriate T L or + joins together and job done.
Measure up your screen. I used a photographic backdrop sheet, 200 weave, doesn’t let any light through which gives a better picture.
Every foot is fine but reinforce the corners as this is where the most stress will be when strung.
A way to attach the screen to the frame. These are those coathook things that you hang on the back of doors.
The first iteration I used bungie ties.
But I found I had greater control of the tension of each part of the screen by using tiedowns
String it up
Other points to consider. You obviously need a projector. If you can’t place the projector exactly front and centre of the screen you get an effect called tombstoning which skews the picture. There are projectors that can correct this digitally but the picture quality suffers. The best ones do this through the lens. The one I have (Epson) has a massive amount of give, up to 50% left/right and 100% up/down. So I point the projector out the bedroom window on the first floor and swing the image over until it’s centred with the screen.
Sound. This took ages to get right. First I tried domestic wiring, phono plugs etc, but over 10m you get lots of noise on the line, completely unusable so don’t waste your money. Go for XLR cables which are balanced. Then you just need the right connectors, for your system, Amazon is your friend here. I played out from a DVD player with phono out for sound, to 6mm headphone jacks with the other end to XLR to the pre-amped monitor speakers. The only thing that I have still to figure out is a remote volume control system.
Have replaced tie-downs with a single long piece of Bungie cord threaded through the screen in a zig-zag fashion. The tie-downs were good but it took in excess of half an hour to put up or take-down. With the bungie cord it can be done in less than 10mins.
Also, a note to home owners. If you build anything in your garden over 2m on a boundary fence expect to get a letter from the council. I solved this by making it a temp structure and just put it up when needed, hence the reason for swapping to the bungie cord for rigging.
The first film I showed on the screen was Ghostbusters and it was epic.
How to make a ukulele
First thing you need is a dad that knows Things...
and then do a little research.
Wear some glasses and measure some stuff.
Draw the outline.
Make a template.
Find some wood. These are Mahogany floor boards from a house that was being demolished around the corner.
Spend ages making them thin enough (1.2mm is optimum.)
A really long time.
Unless you cheat.
Cut the shape with a bandsaw.
Bend the wood into shape. This was the tricky bit, we tried all sorts of way of softening up the wood, from boiling it, to steaming it, to microwaving it. In the end we used a sawn-off section of catamaran mast and blowtorch to heat it up to about 300c.
We used a water spray to keep the wood from burning. The oval shape of the mast was pretty good for getting the different curves of the Uke.
Rig to keep the wood in shape while it cooled down.
Reinforcing the back.
Mum checks on progress.
Gripping stuff. (dad joke)
The bits ready to be stuck together.
I’m not actually sure what we used the lathe for, but it made sense at the time.
This is called ‘purfling’ which is a narrow decorative edge inlay. Usually mother of pearl or abalone, but in this case we used the reverse side of a CD. I want it to be ‘Now That’s What I Call Ukuleling’ but I’m pretty sure it was just a blank data disc. We must have used the lathe for the inlay, a router would have been too crude.
Staining the wood with linseed oil (smells amazing).
This is a Japanese saw, which differs from western saws because you pull it rather that push it. This means the teeth can be much much narrower than on western saws because when you pull the saw it automatically straightens the blade. Because you push western saws the blade has to be thicker to stop it buckling. Anyway this was perfect for cutting the tiny grooves for the fret inlay.
Just needs stringing. Violin strings work pretty well, and tuned to the bottom 4 strings of a guitar, but in this order: GCEA.
And we’re done.
First song: Sweet child o’ mine.
Why is it that when you really need to go to the bathroom at work it’s being cleaned? Maybe it’s just in our offices, but it’s like those cleaners have a sixth sense or something.
So it got me thinking, is there some neat way we could know when it’s being cleaned, to save all those wasted trips?
Well, I was reading about this new type of sensor called ‘tod’ on Kickstarter. The really neat thing is that it uses very little power and one battery can keep it going for years because it uses the new low power Bluetooth 4.0 technology.
If you’re interested in the nitty gritty here’s the Kickstarter page:
So like all Kickstarter projects its running a bit late, but it is funded and all the dev is almost complete. So when the tod arrives I’m going to set up a perimeter ringfence around the toilets via a nearby PC. (One feature that’s very useful is the ability to set the broadcast distance from anywhere between 5ft to 300ft) Next I’ll attach the tod to the cleaning lady’s trolley (when she isn’t looking). So whenever the trolley comes within 15ft of the PC which is en-route to the toilets it’ll trip the perimeter ringfence and automatically tweet that the toilets are being cleaned. When the trolley exits the ringfence it will tweet again saying they’re all clean and it’s business time.
This started out as a pub game one afternoon at the POW, where you combine movie titles with sweets. The next day we photoshopped the best ones together and then posted it to a facebook page and before we knew it we’d had 3 unique visitors. Here’s a sample of our favourites, but check out the facebook page for a bunch more.
Old v New. This is an on-going project to create a chess set with one set turned on a wood lathe and the other set 3D printed.
So I stumbled on this thing a while ago and found it really intriguing. Its a micro controller that interfaces with a computer and allows you to essentially buttonofy objects that conduct electricity. For example you can run pacman on your computer and then use bananas as the left, right, up, down buttons to control pacman. Or you run a virtual piano keyboard on your computer and use people as the key's. Or you can set your webcam to take photographs every time your cat takes a sip of milk. I love the idea of something very simple like making objects into buttons allowing people to create very interesting interactions.
Auto Watering System
This is a project I'm just starting. I have a plant that I've managed to keep alive for about 15 years that I keep in the office. I usually go away to Australia at Christmas to see my family for about 4 weeks and during this time I have to get someone to water the plant.
Now this enters an element of human fallibility into the equation which I'm not entirely happy about. Usually by the time I get back the plant is on its last legs and there's been more than a few close shaves.
So I'm going to try and make an automated system that will water the plant when I'm not there.
For this I'm going to use an Arduino micro controller (similar to the Makey Makey but more functionality) the reason i'm choosing this is mainly because the programming language is based on C and that's very similar to the C# that I've been learning to write games in Unity.
There are a couple of things which I want this project to achieve:
- Be self sufficient for at least 8 weeks.
- Only water the plant when the soil needs it, rather that on a timer.
- Use solar panels to re-charge the battery.
- Use a syphon to top up the water reservoir.
- Alert me via twitter/email if there is a problem.
So far all I've got the board doing it blinking a LED on and of at varying rates. But its a start, so come back regularly as I'll be updating the project every few weeks or so.
So, major breakthrough today. Have successfully wired a relay to the Arduino to trigger the pump. Need to use a relay as the pump runs on 12V and the Arduino only on 5V or 3,5V. So have hooked up a 12V battery to the relay and pump and its all working fine. Have tested it with a modification to the blinking LED code and can now turn the pump on and off at regular intervals via the Arduino.
Next step is connecting the moisture sensor and configuring that so it triggers the pump when needed. Stay tuned.
Have got the moisture sensor and been playing around with it this morning. There's not much documentation, so I plugged it in and hoped for the best. The moisture sensor can be plugged straight into the Arduino, used much like a resistor which in some ways it is. However this is a bit limited and you might as well use a couple of nails as the sensor instead. this sensor came with an interface which allows either digital or analogue output which then plugs into the Arduino. I wasn't sure which one to use so I've done a little digging and both have their uses. Digital gives you yes/no reading based on a threshold.
Oh one other thing I forgot to mention was the interface board has a potentiometer so the threshold can be adjust very easily with a screw driver. But I also tried the analogue output. This gives you a range of readings depending on the resistance.
I'm leaning slightly towards this approach for the moment as I've set up a Serial.println that and have adjusted the thresholds in the code so when the sensor is in a glass of water (maximum saturation) is says "too much water" when its in moist soil it reads "just right" and when its in air (maximum resistance) it says " thirsty". In the future I'll have this tweeted to a stream but at the moment it displays in the serial monitor.
Next step is triggering the pump when the reading returns <300 "thirsty" and switching off when is reads "just right" with a failsafe for "too much water" >1000
I was having real trouble getting the relay to activate when the Arduino was HIGH, so I skyped my dad about it and we deduced that the relay was active LOW, which means it 'on' when there is no current. Bizarre, but at least it wasn't a problem with the code or board. So anyway dad drew this up to fix it and make it active HIGH.
So needed something to put it all in. Decided on two 150mm perspex cubes, one for the electronics, one for the water.
Finished, for now
There's some more functionality I'd like to add at a future date, like a power conservation mode to extend battery life and a wireless module so it can tweet updates on how the plants feeling etc, But for now I'm beta testing it as is with a basil plant to get a sense of how frequently it needs watering etc. Also there's another project I'm working on that's taking up a bit of time involving the Oculus Rift Dev kit 2...