Electronic Ideas and Experiments

LED lights.

This is a simple idea which has already led some local artists to make shiny balloons to light up a pier, and has inspired a teenager to start a business and win various entrepreneurial and inventing awards with something that leaves most open hardware or electronics enthusiasts cold and blank.

Basically the most simple thing you can build using electronics is an LED attached to a resistor, and both ends of those two, attached to a battery. Another simple variation on this is the throwie, which is LED + Battery + magnet (so it sticks to what you throw it onto).

To many this is old stuff, far too simple to be interesting any more, but to me the simplicity of the design is beautiful:


But it's actually a lot more fluid than that picture, made of bendable wires that could go anywhere, and could be arbitrary lengths really.



LED light can be very directional and will project really nicely on to things, so an LED tree made of wire or pipes that you can position seems a good idea. LED technology is also getting better fast. Switches to turn on or off can be made using just metal bits or pins so there's loads of space for considering not the electronic aspects, but the design of the object and what it would feel like or what it would be for. So doing some kind of LED lighting unit where each one is switchable and autonomous would be brilliant. But how to do it...

I would like to create an LED light system for a tiny stop motion home theatre using my Arduino. I have to find out how to power at least 3 different coloured LEDs. I think I have 5V so maybe I need to figure out how to do the lights at different times. But then what to encase them in so that they are easy to position, and how to turn them on and off. Here is a simple lighting test I did:




Solar power

Once I'd build my first arduino based prototype, my main worry was those huge panels of 4 AA batteries at a time that are needed for this kind of thing. It is far too much consumption and the first thing to do would be to switch to rechargeable batteries.

Once you have rechargeable batteries though, the next step is to figure out how to wire in a small solar panel and let it be self sufficient. The thing I want to be self sufficient will be able to generate sounds from a buzzer in some kind of container that can naturally amplify it(a pumpkin has been suggested for this), as well as play electronic beeps to it, from a piezo. So it follows that if this is playing all day it will be annoying, whereas if it uses only a little energy and has to save up energy before it can play for a while, it will only give a couple of concerts a day, which may be more interesting than a constantly sounding device.

http://little-scale.blogspot.com/2008/03/connecting-solar-panel-to-arduino.html
http://www.instructables.com/id/Self-Sufficient-Arduino-Board/

http://residentialsolarelectricity.diycreation.com/sun-tracking-solar-panel-w-arduino/ <- fun stuff


White Noise Generator
I want to do a psychological experiment using sensory deprivation to induce a hallucinatory state. This will use a white noise generator and ping pong balls remove auditory and visual inputs from the wearer, excepting the LED lights which will follow the overall luminicence of the device and light up at some moments to trigger a colour perception. It will need a simple and small hat with the required attachments: a white noise generator, and some LEDs that light up randomly at the side of the eyes when the room darkens and a light diode to detect light (although this can be done with an LED as well).

Initial links to useful chips and bits that might help:
http://www.edaboard.com/ftopic302943.html
http://www.maxim-ic.com/appnotes.cfm/an_pk/3469
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1521
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1169001613
http://processing.org/discourse/yabb2/YaBB.pl?num=1234706777

Marcus Valentine suggests using a linear feedback shift register to do this with, and John Honniball says this would need quite cheap chips, easily available here and there. Here are some links explaining it:


http://web-ee.com/schematics/noise_generation/scalable-noise-generator/
http://en.wikipedia.org/wiki/Linear_feedback_shift_register


Using simpler chips and boards than Arduinos

The natural progression from using an arduino to prototype something is to want miniaturisation and to try and make the thing cheaper to keep as a permanent object. I don't want to have to take my arduino out and build it all back up again each time, so circuits will get soldered, and ideally, the arduino will be then used in turn to program a smaller, less expensive chip with what is needed to just do it's job (minus all the USB connection and other arduino stuff that make them simple). The end result is you have a small device you can make more of, running on a simple chip. This can work well for stuff like musical instruments or other semi bespoke work.

http://shop.tuxgraphics.org/
http://shop.tuxgraphics.org/electronic/detail_avrusb500.html
http://www.futurlec.com/
http://fundamental.antville.org/
http://code.google.com/p/mega-isp/
http://drug123.org.ua/mega-isp-shield/

Beyond the netbook: Making the simplest open source arduino based microcomputer

Today's arduino based microprocessors are no match for the computing power of an ARM chip. Most of these chips can easily run Linux, or proprietary systems like WinCE, and they power most of our phones as a result of much earlier electronic experimentation, as show by last week's Micromen BBC program, about the Acorn vs Sinclair battles of the 80s.

A fully capable ARM chip able to control a complex thing like a mobile with it's full color displays and wifi, 3g bluetooth etc will cost a minimum of 150 pounds(and that's just for the chip), and so for hardware hacking isn't really worth the investment, as no-one will buy it for £150 when you can buy a proper ARM based phone at Tescos for 15 pounds.

But an arduino can still be the basis for some kind of cheap system, perhaps one that costs only around 50 pounds to prototype.

What I'd like to see though isn't a project to make something that mimics phones, but is to make a functional leap and create the simplest possible thing that can serve as a household computer, taking the most basic functions: communication, data transfer, storage and interface, and concentrating on being low power, cheap to make and open in design.

Things to use:

• Voice: OCR to Voice, voice to text etc, getting rid of keyboards. (Although the processing power needed for this might not make it a good idea. Maybe it would only record messages, send them around and play them back.
• "Touchscreen" or head tracking as with http://johnnylee.net/projects/wii/ and other ideas.
• Casing: Recycled materials. Tire, sensors from old electronic items, mass produced plastic packaging etc, natural materials such as bamboo and balsa.
• It could use sd cards for storage, send data over audio channels, and we could copy data in and out using the miniusb.
  
• Could a photo sensor and piezo combine to create an interface perhaps? The photosensor would do distances, and piezo would check for sound. Sound + distance can easily reproduce the rubbish but simple keypad used in mobiles.
  
• Display: The tellymate! http://www.solarbotics.com/products/50652/ but if it can plug into an old flatscreen monitor, all the better.
  

There has to be a cheap way of generating images or sending data. Using ethernet and a fast local network, it can control a huge array of devices, and there are new technologies coming out all the time such as 3g modems and IP over electricity.

With the basis of an arduino, or of it's cheaper clones, an open hardware device could be created able to plug into a monitor or a television and use a modern but inexpensive interface such as IR gestures or touchscreen, powered by AA batteries or crank power!

So here are some links I've collected to do with ARM chips and netbooks:

http://news.cnet.com/8301-13505_3-10198879-16.html Ubuntu triumphs in the modern netbook market.

http://www.embeddedarm.com/software/software-arm-linux.php A linux ARM distro for a specific chip, price TBC...

http://www.embeddedarm.com/products/arm-sbc.php $110...

If a workshop was set up to make something that sold for £40 pounds or less, people would buy it. But the sets could take the price down to half of that if it was just simple parts and lots of inventiveness...

A weekend building an arduino based robot

[The bot itself, looking sombre]

Last month, I went away to Stourbridge, a great centre of technology and robotics in the UK's scenic midlands. Here are some notes, pictures and film from that journey.

(I lied about Stourbridge).

The little train that brought me over from the main rail routes felt like a mix between the Totoro cat train and the slowly chugging train of death that inevitably carries away dead steampunks.

I later learned it had been built with very little money, so the health and safety was very minimal, and it was always breaking down.

But my friend Mat lives on the side of this sleepy town. He said that to one side of his house there was wasteland and empty industrial buildings. The other side, he warned was a land of chavs with blue neon underlit cars, there were also pubs and strip clubs, and lots of nurseries.

For a long time, Mat had been collecting arduinos and sensors of all kinds, hoping for a weekend of calm in which to play with it all. He invited me over to build a sonic robot.

So I had gone over for a weekend of playing with cool tech, which turned out to include generative sound with PD and Max MSP, arduinos, robots, cameras, c++ libraries, and lots of gaming. It's for a show he wants to do next year.

We also talked about the idea of a combined virtual and real tree: perhaps feeding into each other. My tree would live in Second Life or Opensim, and would be made of a robotic avatar, which would talk to it's attachments and generate detachable fruits if it was paid Lindens or fed nice textures. Mat's would live in real life, made of arduinos, servos and LEDs, and might for example produce virtual fruits with a GPS location that you'd need an AR platform to go and find them with.

So Thursday was a quick introduction to the arduino. We did the first hello world tutorial and got out Mat's extensive collection of arduinos, roboduinos, arduino diecimila, cornettos, arduino super maxis, calippos and mars bar ice creams. So after getting one LED's worth of blinking satisfaction, we created two little things out of plastic:




To make these, we sawed a CD box cover in half, attached three ultrasonic oscillators on either side (which were bought for a tenner each at coolcomponents.co.uk). And inside the box covers was a little arduino, controlling it. Our idea was to then wire this up so that music could be played based on it's tactile nature, and based on some 80s experiments with infra-red range finders.

But then we got out PD, and started playing around with that, as well as getting out loads of computer games like Left 4 Dead and Fight Night round 4 - great inspiration for messing with electronics and sound generation.

So next morning came a fun Puredata workshop, downloading it, setting it up on linux, and generating random sounds in our stoic Stourbridge surroundings, a local JD Wetherspoons, to the annoyance and tutting of the locals. I learnt that you can wire up Playstation 3 controllers to PD via USB and they will control anything on the PC. It looks a lot harder to figure out than Max MSP but in it's help files' introduction page it mentions Xenakis and Stockhausen.

And then, after some stir fry, we put together a robot kit, the kind you buy at bookshops or museum shops. This one was from Robot Shop (although I can't find a link to it direct. Mat says it's called the Rover though). We ripped out the frame and the wheel motors and attached them to an arduino. After we'd put 20 tiny bits of metal inside 20 tiny little holes on each track, it was quite easy to get the arduino controlling a single tracked wheel, but there was not enough power to run them both, much less to carry loads of shit around like a robotic pack horse mini me. It would have needed a transistor and a 9v battery, which means a trip to Maplins.

So we sidestepped that whole issue and added the contents of a £50 Edimax webcam and wifi pack to the robot.

[To indoctrinate robots into the human world, it is traditional to filially imprint them with some late night Jonathan Ross]

We removed the webcam from the white side of it's plastic container, displaying it's internal LED(s) as well. This we then taped on to the robot box. and on top of the whole thing went the WIFI router, which was also in the pack from edimax. I soon downloaded an android IP cam app, and had connected to the camera over the wifi router, although being plugged in doesn't make our little robot any better at being autonomous...

But we could add batteries at some point. It needs either a 6v, 9v and 12v battery, or just a rack of AA batteries like a radio controlled car.

[Slightly menacing blue lights, again showing a strange resemblance between television and sound bot]

We also thought of using one of the range finders for it, so that it would have an easy way of avoiding obstacles, but then Mat's games with video to audio pretty much got rid of that need.

And we took loads of photos of the photos it was taking. But to get the camera working on linux, I needed a bit longer, as I had to download all the info and a big 150 meg library to my g1 (As a sign of the times, there was no working internet in the flat, but we both had it via 3g on our phones, which we'd use to transfer files via USB cable).

Meanwhile, I wrote my first C++ library for arduino, stealing shamelessly from a Twitter library, found online, which was able to deal with basic authentication.

So easy to make robots nowadays! I bet in future our robot dolls will be home made too.

I'm back now, a few hours later. We've taken a slight detour with a Max/MSP patch that interprets Mat's Mac's camera and turns it into ostinato piano notes based on how bright each pixel is. After that, Mat enlarged it by 250 times, by taking each pixel in a row and doing this based on the average. It's about as good as the range finders were to begin with. We had loads of fun and made a couple of videos of Mat playing his computer like a piano sampling theremin.

It's also, to my mind, a lot more accessible than a range finder, ultrasonic or IR, because everyone has a camera in the UK and everyone is being videoed or is watching video constantly through the day.

Imagine an installation where you took over all that CCTV in a space, and used it to generate sound based on the people passing through it.



I kept working on my C++ library, and it is now able to log in, request a page, and get an error code of 200 from the camera. Also, you can now install it in the arduino development environment and it will run out of the box, even giving an example. It's not much really, but it was late... And with the pdf of the cgi calls, it will soon be able to deliver lots of info to the arduino based on the images it sees.

Next step will be to get the little camera for the robot sending data back to the Arduino, so that it can pick up visual info and use it to tell where it's going. I had a geeky time messing around with the arduino and it's Ethernet shield, getting it to be a web server and client(ooh, arduino p2p, I count the days until your birth), but unfortunately still not managing to get it to connect to anything useful.

Mat's final vision for the robot is that it is eventually able to find it's way around using the camera, and able to find the most musical place, so that in it's symbiotic relationship with humans, it can deliver pleasurable noises. We also still kept the first basic idea of using our original rangefinder interface, maybe mounted on the robot, or in an area close to it, so as to allow people to play duets with the robot, and find even better noises based on what it finds.

[Our little robot relaxes after a long and arduous hacking session]

How to do memory:
Instead of storing sound samples on an SD card (which could also be good, for obtaining on-board recordings), it could store much more data based on the images it sees, before it turns them into noise. On a 9 hour day, 15 frames a second, so for a minute it would need 900 samples. So for an hour, 54000 samples. it would have 486000 individual samples to take care of. BUT each row of elements has 256 individual integers. So that gives 124 416 000 bits stored in a day, i.e around 15MB.

But that's only if it was gathering this stuff all day: it only needs to gather the stuff it likes(based on an algorithm Mat's got in mind), so maybe a 30 sec vision based sample at most, which would then be stored on the SD card so that it could be played back in combination with other stuff it liked. Samples could maybe be stored in 3 types (Lady Ada's wave shield allows the playing of 3 sounds at a time - enough for percussion, chord/drone and soloist/multiple tones).

Mat's algorithm would do a fitness test:

   is this a C major chord, or a scale, or something I can identify?
       Yes:
           What type is the sound: percussive, slow tone, quick tone?
               store a segment(type)  
           Move slightly forwards or back to try and get nice variations.
       No:
           Turn X degrees left or right.

Arduinos and bits bought from:

Devonrobotics.co.uk, corecomponents.co.uk
Robot shop construction kit: £40 including an arduino!
Lady Ada Wave shield kit: also quite cheap, and including another Arduino.
skpang.co.uk : very cheap bits and oscillators.

Dorkbot's New Hackspace

Here below you see a miniature, or pocket version of what was recently displayed at a large event in Bath by the newly hacktivised dorkbot bunch, who were given the challenge of providing a musical experience for a tech related arts event. They had to build a smaller version for testing, so they say, or most probably, because they could and because it was fun.




So Dorkbot has finally grown up from being a show and tell of the media, design, internet, engineering, musical and generally creative dork-peoples of Bristol. It has now gained much attention from event organisers and maker faires, as popular electronics has it's second rennaisance in arduinos and strange inventions, and as the closet sound benders of Bristol started messing with all that, so they are booked to play quite a few places, in the sense of course, of playing strange new-millennium unicycles that generate sounds by bending a microprocessor's own vibrations.



Tonight, we plotted the needs for the upcoming (23rd and 24rth October) event in Cardiff, where many a sound unicycle will parade the streets(um, of the venue), a veritable orchestra in fact, for which bass parts are now sought. Here is the shopping list for now:

2 Sunshields for bike wheel (to shade a small section at the top where the optical sensors are)
2 Battery packs for 6AAs
2 Arduinos
Wires
3 or 4* optic sensors
£4 speakers from the garage near John's friend's house
2 power plugs
2 jack sockets.



* The 4, as explained by John Honnibal, was due to the possibility of having an extra track around the side of the disk, which provides the musical score for the device, and to have that synchronise the other notes. This is shown in the first image, at the top of the blog post.

But perhaps I should explain a bit about this space that has been kindly given to Dorkbot by local networkers and community IT group Bristol Wireless, so as to be used as a Hackspace. It's housed at Hamilton House in exotic stokes croft(where from the bar below, a local play takes place each day, next to Bristol Wireless's offices, and so far just an internet connection, some power sockets, and lots of possibly useless, potentially dangerous electronic devices in large plastic containers. Oh and some unicycles.


The idea is to keep it running weekly as a time in which to make stuff, rather than show stuff you've made as with the Pervasive Media Labs sessions. I hope those like me who have never done a day's soldering in their lives will soon learn to count their ohms, tell their resistors from their capacitors, and others will get to work with interesting people who bring their creations to new audiences or new collaborations. But the Dorkbot, mixed media feel is not lost. It's still meant to be a mix of whatever is made by electricity, and I hope the musicians and engineers can be quickly joined by dancers, poets and cooks. (But I do also remember a Cube Cinema based dorkbot where even the electricity rule was broken, and most of the show and tell was about open source cola and distributed apple tree orchards).

So, we now have a bristol hackspace, and lots of things to build each tuesday, for upcoming events, some leaning more towards outreach(such as a busking and empty shop takeover event in late November), others more towards art(such as the Arnolfini's December based IT/hacking programme). I must end with another list, this time of the first hackspace invention ever to be built as a kit and sold. Here are some of the parts that might be required:


In each pack (of a total of maybe 20 packs?):

A small used flyer, or some thin cardboard on which to print a circuit board and on to which the device will be assembled.
1 diode
2 capacitors
2 potentiometers
Chips
etc

1 pack of 20 or 50 plastic parts ziploc bags.


As well as this creation, allowing people to come to a workshop and go home with something interesting, we'll also be on the lookout for some cheap sound making toys from pound stores or toy shops, so as to circuit bend these as well. Meanwhile though, I'll definitely have to learn to solder!

Where's the Salad?

A while ago, I put on an event in which people from Bristol grew and made a salad, based on Alison Knowle's "Proposition No 2":



It was very nice, and I made a preparatory video:



as well as there being a radio interview, a sound art play with radio and some homemade chopping noises(with poet Andres Andwadter), lots of photos of the event itself and some graphics about it. But I want to make this, as well as more audio, this time of the live chopping duet between lollorosso and improvising trio, into a video and tell the story that way. So I'm really sorry, but it's going to take me a while. It was an incredible experience, and thanks to all who came. Especially to those who brought us salad!

A list of future physical/virtual computing arts projects

I have to write up so much from recent events, but as usual at these times, my head is buzzing with ideas for other stuff to do next (all based on a long weekend of messing with arduinos, robotics, Puredata and Max/MSP), so I thought it best to document that first. So. I would like to make:

• An enactment of a score I wrote a long time ago, involving dancers/actors performing with a box, that follows different parameters based on what stage the performance is at. It would be a black box, interacting with the movement and words only through sound. It would be capable of "jamming" or following music in some way or other. (Link suggested by Mat)
  
• A dance based implementation of the MaxMSP script that my friend Mat quickly put together last weekend, which allows webcams to interpret visual data as audio samples(more on that in the next post). I want to invite a duet of dancers to perform with this webcam audio, in December, but mostly scriptless, just a result of trying things out with the kit and seeing what shapes to pull so the sounds are better!
• An outdoors sound object capable of sensing it's environment (possibly via sensors able to see light and soil moisture, so a bit like a plant again). It would turn those senses into audio. I would program it with my own samples and prototype it with PD, though so it would sound somehow like my own thing. The main part of it would be that it could play a morning raga: if it's dark, play a generative solo sound. As sound increases, find a melody and vary it, keeping the main bit for later. Percussion joins in when light reaches a certain moment, and follows warmth or moisture. I've got most of the bits of this. I'm wondering how to keep it safe out there in the rain and damp all the time though. And I want to get it solar panels and make it self sufficient, or even read more data from that into music as well!
• An exhibition, soon, of the musical robot we prototyped and got started this weekend (looking for venues at the moment).
• The two trees, from the previous post. This will hopefully debut on Burning Man's Second Life incarnation, Burning Life.
  
• Maybe in future, a watcher system to protect plants against night time garden pests. It would have a wire going into each plant pot. It would use the noted aversion that slugs and snails have to small electrical charges (this is why they don't like copper), together with a motion sensor or some other sensors, to (gently) zap them whenever they come by. The natural extension of this would of course be a mobile robot that had all these things in it, and a good way of finding it's way around the garden.

So some of these are very real and coming soon if not here already. The Burning Life land grab is tonight (3am! late night tonight for me then) for example, but other things I just want to note down for the future...

A tree spirit for Opensim / Burning Life

I want to make a self replicating distributed bot + attachment system, which is coupled with a physical computing version of itself which my friend Mat Dalgliesh is making as a physical creation.

Here is the spec:


The tree idea is a reflection of a physical computing tree, created using arduinos, sensors and motors.

Leaves are attachments with a built in fall script. When they fall, they slowly degrade, becoming darker until they become a particle effect and delete themselves. New leaves take donations from users. If they get donations, they grow bigger and live longer. They pass this donation to the trunk who divides it around the rest of the plant.

Here is a little bit of a proto-leafgen script:

// Rez an object on touch, with relative position, rotation, and velocity all described in the rezzing prim's coordinate system.
string object = "Leaf"; // Name of object in inventory
vector relativePosOffset = <2.0,>; // "Forward" and a little "above" this prim
vector relativeVel = <1.0,>; // Traveling in this prim's "forward" direction at 1m/s
rotation relativeRot = <0.707107,>; // Rotated 90 degrees on the x-axis compared to this prim
integer startParam = 10;



default {

state_entry() {
vector myPos = llGetPos();
rotation myRot = llGetRot();

vector rezPos = myPos+relativePosOffset*myRot;
vector rezVel = relativeVel*myRot;
rotation rezRot = relativeRot*myRot;
llSetObjectName("Leaf");
llRezObject(object, rezPos, rezVel, rezRot, startParam);
}

touch_start(integer num_detected) {
llRequestPermissions(llDetectedKey(0), PERMISSION_ATTACH);
}

run_time_permissions(integer perm) {
if (perm & PERMISSION_ATTACH) {
llAttachToAvatar(ATTACH_RHAND);
}
}

}



Fruits are controlled by all the other parts: they accumulate currency, and can spawn more of themselves when small. When big, they have a drop script. It becomes a little ball that gives something nice, like textures, or sim currency when picked. Just before it drops, it transfers any remaining goodness inside it to the trunk



The trunks are all bot avatars, run after being prepared by humans. Each time the tree needs to grow by another bit, another avatar is needed to be attached to a linking attachment. By use of animations, they could even be intertwined with each other. It uses currency to upload textures of it's older self - used in all other parts. If restarted, the bot scripts will start from seedling.

The avatar is heavily made up: it will have trunk and root- like attachments. sounds and animations, and then generators for the fruits and leaves, It is a bot, communicating with the attachments it wears via hidden channels. Maybe that's how a tree spirit should.



Roots are born when the tree is on some land. They could be non physical and locked to a place, so they function as an anchor. It can be engineered that only way it could be moved would be by the addition to the tree of a rooting script, temporarily making the tree physical. Not sure if these will be needed really though.

To kill it, because it can respawn trunks which automatically wear leaves and accumulate money, you would have to ddos all the bots that run it, and they can be connecting from different servers, which could make it quite a resilient little plant.

So this is an opensource project at the moment. It is a cross between content, character design ecology and commerce. It should be fun! Let me know if you'd like to be involved!