Lights and Taps

No more drips...

The lawn needs mowing. The upstairs is covered in discarded music CDs. And the kitchen tap has been dripping for ages. A perfect time to start building a computer controlled led display for downstairs. Or perhaps not.

At least I've fixed the tap now. Modern taps are strange. When it started to drip I went up town and bought every sized tap washer that I could find and then set to.

As soon as I took a proper look at the tap I discovered that it doesn't use a standard washer, it uses some strange right angled tap device. A quick search on the internets revealed that a lot of people solve this problem by purchasing new taps. Which wasn't entirely helpful.

So I did a more careful search and came up with these beauties. They dropped in as a direct replacement and work a treat. A little tip though. Make sure that you put them on the correct sides otherwise you'll end up on Amazon complaining that the replacement taps work fine but their action has reversed and the up position is now on rather than off....

I'm going to tidy upstairs and mow the lawn later. And the lights and controller boards are in stock. I love having a project on the go...

Whelmed by the Galileo

A Galileo with a very distant relative

There is a wonderful exchange in the film "Ten Things I Hate About You"* where one of the characters poses the question "You can be overwhelmed. And underwhelmed. But can you ever be just 'whelmed'?". I think you can be. And I've just found the thing that does it. I've been playing with an Intel Galileo board. And I must admit that I'm totally whelmed by it. 

It looks like an Arduino that has been eating all the pies. It has all the connections that an Arduino has, but they are subtly less useful (more of that in a minute). It is based on the Intel Quark architecture which is a complete system on a chip. The Quark is the tiny thing right in the middle of the Galileo device. The Quark chip provides serious amounts of processing grunt, and it is coupled to 512 megabytes of memory. It runs a flavour of Linux and you can put bigger versions of that operating system, plus a lot of data, on the micro-sd card.

Flip the board over and you can find a PCI Express socket which could take all kinds of high speed devices.  You can also connect the Galileo to a wired network and it will work a treat, and you can run Python and lots of other stuff. And you can plug Arduino shields into the board and directly interface to hardware. That cat-flap that sends you an email each time the cat goes in or out is well within your grasp.

So far, so neat. But it is expensive, at over fifty pounds it is around five times the price of a single Arduino clone. And the Arduino hardware ports are limited. While they are electrically the same as the ones on your trusty Uno they can't be updated at more than 230 or so Hz. This rules out driving things like NeoPixels from the Galileo. It supports USB hosting, but you have to have an extra connector, and you need a really funky cable if you want to do serial communication with it. 

If you really want to have Arduino compatibility and some unix power round the back you should probably get a Yun device. This is cheaper, smaller, lower power and you get WiFi thrown in. If you want to do proper unix with a bit of interfacing then the Raspberry Pi might be more up your street. And you can plug a monitor directly into that. 

The Galileo is not a bad device. It is just not anything other than whelming at the moment. That could change though, remember that Quark computer on a chip. It really is tiny. If Intel release a slew of properly small and properly cheap Quark based platforms, then the Galileo would be a fantastic place to prototype the next generation of "internet of things" gizmos.

Update: The review above is all about the Galileo that I paid money for, arrived in a box last week, and I've just had a play with. It is not about the Galileo that Microsoft have been giving away as part of their Internet of Things effort. I signed up for that, but nothing has come through yet. Thanks to leonellive for pointing that out.

As far as I can tell the IOT device is the same, but it comes with an SD card containing a different operating system that is Windows based and you can write programs using Visual Studio. Now that might be a lot more than just whelming. (Does anyone know where I can get an SD card image?). 

* If you've not seen the film, or you have and you want to relive the magic, head over to this fantastic essay all about it from Bim.

Pegleg Hexapod

We got the Hexapod robot going today. He sort of walks, but has bother doing a straight line. And as for floor mats, forget them.

We are working on an appropriate name at the moment. Any suggestions appreciated.

Playing with TinyDuino

One of the things I love about the Arduino platform is the huge number of different form factors that are available. This has got to be the smallest I've seen so far. It is TinyDuino.

The picture above shows some of the boards and a Starburst to give an idea of scale. The devices are, clockwise from the Starburst, processor, Bluetooth BLE, Accelerometer and programmer. The boards stack on top of each other using the tiny connectors.

When you want to program your device you put the programmer board into the stack and plug it into a USB port in your PC. It appears as an Arduino Pro-Mini clocked at 8Mhz (use the 3.3 volt option). It has all the pins of a standard Arduino uno and you can stack a tiny prototyping board onto the end of the stack if you want to directly access the signals. Once you've programmed your processor you can remove the programmer board to make your device even tinier.

There's a lovely little 16 LED array you can put on the end of the stack, and also a circular row of leds you can program up for a super-tiny cylon effect. There are also wifi, Bluetooth and even motor control boards you can add. The BLE device is a bit longer than the other ones, but you can still create really tiny devices with this platform. One version of the processor board has a clip for a lithium battery so you can easily create self-powered devices. 

They work a treat and I strongly recommend them. However I would mention one word of warning. The manufacturer has recently changed their website and so all their documentation for the devices has moved around and is now very hard to find. If you need any help with the platform you are mostly on your own.  Having said that though, most of the boards are based on very standard technology and so once you install the appropriate Arduino libraries they will work just fine.

I've been trying to get the Bluetooth BLE device to work with Windows 8.1 and not having a lot of success so far. I think this is down to my not understanding the way Bluetooth BLE works. The idea is to make a "ring of power" that I can wear so that I can send commands to my devices just by waving my hands. We shall see....

C4DI Hardware Hacking

Last night we had our monthly Arduino hardware hacking session at C4DI. Lots of the regulars were there and one person even brought her long-bow along. Which was a highly impressive piece of wood. 

The theme of the evening was Sci-Fi movie effects, using programs to make whooshes beeps and all kinds of space age noises. You can find out what we got up to (and even have a go yourself) by grabbing the lab sheet from here).  Great fun was had.

I brought along my latest purchase, an Arduino powered pen pushing robot that you can pick up from RoboSavvy for the amazing sum of 18 pounds. Peter and I had enormous fun building it, particularly when we (or more accurate I) wired the motors the wrong way round and had the robot printing perfectly - but from right to left). However, with a bit of adjustment we got it out of "arabic mode" and managed to get it printing properly.

Windows Phone, Wedding Lights and Bluetooth

Windows Phone connected Wedding Lights. Eight synchronized lights which can be controlled over Bluetooth. Each light contains an Arduino processor and a 16 NeoPixel ring.

I've finally finished it. I was going to write an article about my Windows Phone Controlled Wedding Lights. But instead I thought I'd do something different. So I fired up Adobe Premier and I made a video about them instead. It only lasts a couple of minutes, but boy was it complicated to make. Anyhoo, feel free to take a look and let me know what you think.

I've done something else I've not done before (and I feel a bit guilty about this one). I've put the Bluetooth code for Windows Phone 8.1 and Windows 8.1 up on Codeplex. I'm ashamed to admit that this is the first code that I've ever posted there. I really should have been posting stuff up there earlier. I'm determined to post more stuff as I come up with it.  

You can find a sample project (my Bluetooth Printer) and the BluetoothManager class that I used to communicate with the embedded Bluetooth controller. There are also details of how to configure the Bluetooth device and send and receive data. 

Tricopter Flying

What happens when you strap three motors, a battery and some bits of electronics to some lumps of wood? You get something that flies, that's what. After overcoming our initial nerves from a while back we managed to get some quality flying time in on Sunday morning. The amazing thing is that it all worked.

Number one son now has a fully working tri-copter. It seems to be happy to hover on around a third power, which means that it should be up for camera lifting duties quite soon.  

Tricopter Nerves

Number one son was around over Easter and spent quite a chunk of time building a tri-copter. This is like a quad copter, but operating in reduced circumstances as far as rotor count is concerned. However, in some ways it is more interesting to fly, because the third rotor is pivoted so that you can use it to vector the thrust in a way that quad copters can't. 

Anyhoo, he started with just three bits of wood and a bag of motors and controllers and stuff, and I printed some parts to help hold it all together. By this evening he was ready to take it out into the field and see what happens. 

The answer, on this occasion, is not much unfortunately. Although the good news is that everything is plumbed together fine and it all worked as expected, the bad news is that a different kind of propeller will be required. I'm a bit sad that I won't be able to see the maiden flight of the device (it goes back down south tomorrow), but I think there is a good chance that it will come back to Hull in one piece at some point in the future. And I'm seriously tempted to have a go at building one myself. 

Wireless works better with Wires

There is apparently a difference between seems to work, and actually working. I spent a good chunk of today finding this out. The devices you can see here are used to send wireless signals from one place to another. You put a signal into the input pin on the transmitter (the one at the top) and it emerges from the receiver.  People say they seem to work. So I thought I'd have a go with them.

The first thing I did needed to do was prove that the devices work so I wired up a couple of Arduino controllers and used the lovely VirtualWire library to waggle the wireless signals up and down and transfer data. It worked first time. Yay for me. 

I really wanted to use these devices to transmit signals to control some lights, so the next thing to do was write some code that turned the lights on when it received the appropriate commands. So I wrote that and ran it and it worked. But only once. Not so much yay.

So I built a theory that light software and the VirtualWire library were fighting over Arduino hardware and losing data as a result. And I spent a while trying isolate the usage of the signal pins that they use. And getting nowhere. 

And then I had a brainwave. I took out the wireless devices and replaced them with a piece of wire between the two Arduinos. And the program worked perfectly. Flickering lights and everything. 

Most confusing. After a bit of thought I reckon I've figured out what is happening. The receiver likes being given a nice healthy 5 volt supply. And when the program starts running it gets exactly that. But when I send the command to turn some lights on this causes the voltage to drop (taking current out of a system often causes this) and so the receiver stops working. I'm now working finding a few volts from somewhere to beef up performance.

Working with hardware devices is like this. You don't just have to get the software to behave, you also have to consider the electrical environment too. But I'm still having fun.

Get a Multimeter. Preferably with a needle...

If you are at all serious about electronics you probably need to get a multimeter. This is a thing that lets you measure electrical items of various kinds, voltage, current and resistance. I got my first one a very long time ago. In fact, they were quite expensive and I actually ended up buying the bits and putting my own box around the thing. 

Nowadays you can get them very cheaply, and they tend to be digital. They show their readings as numbers. This is fine, but I much prefer one with a needle, like the one above. With a needle it is easy to see if something has just gone up or down. With digits you have to start comparing numbers. Most of the time when I'm testing a circuit I'm really checking to see if something is there or not and I don't really need an accurate value.

I thought you couldn't get cheap multimeters with needles on them, but it turns out I was wrong. You can get the above for less than five pounds from here. So I did. It works well enough and I'm already finding it useful to have around the office.

One important note though. As you can see above the dial has settings that indicate that the meter can read up to 1,000 volts. This is true enough, but you really, and I mean really should not be poking those kinds of probes into signals at that level, on account of a mistake making you suddenly, and electrically, not alive any more. For battery voltages and things like embedded controllers its fine, and it can also measure resistance.  But for high voltages I'd suggest you look at much higher specification tools that will have better insulated cables and probes.

Mastering the Crimp Tool

I spent some (oh, alright, quite a lot) of today fiddling with hardware, as is my wont. I've been buying cables with ready fitted pins and sockets on them, but last week I thought that it might be useful if I could crimp my own pins, so to speak. So I bought a crimp tool like this one.

The theory is/was that I could make up custom cables of just the right length and with just the right arrangement of plugs and sockets on each end to fit in what ever I was building. And it sort of works. There's a very useful howto on the Hobbytronics web site and by the end of the day I was able to make pretty good connections, which is nice.

Having said that, you can get ready made cables of ebay for around 3 pounds each, which give you forty connections, and so I think I'll just get this out for special occasions. It's one thing to be able to use it, but another to have to do it a lot.