The world's most awesome MIDI instrument

This is a Tesla coil that can be played as a musical instrument. According to the information on the supplier's website it can be driven directly by audio or as a MIDI instrument. The tune is being played by the arcs themselves; by switching them at the appropriate frequency the corresponding musical note is produced. Awesome :-)

Chris at work pointed me at this one as well. Like :-)

Categories : Tech

As it says, "Beautiful light performance"

Well, we did our first performance with the LED strips on Wednesday at Islington Mill in Manchester,and I'm relieved to say they worked flawlessly, even after one of the wheels was dropped just before the performance started! The lighting in the venue was a bit too bright to make a good video, so Andy made a video of the strips in action at Thursday's Travelling Light Circus rehearsal which he's put up on YouTube. Even though I say it myself, I think it's rather good :-)

Seeing the strips in use by the talented TLC performers just gives them an entirely different dimension, and I think the video is really well done as well. For me, one of the best bits of the project has been the opportunity to work with people who have an artistic clue :-)

Categories : Tech, AVR

Connecting a HL1606 strip to an ATmega

I've been left a comment asking how the HL1606 strips are connected up to an Arduino. The wiring is really pretty simple, but depends on exactly which ATmega version you have, as the hardware SPI pins vary from MCU to MCU. The following assumes it's a ATmega328P as used on the more modern Duemilanoves, you'll need to refer to the MCU documentation and the board schematic to find the correct ports and pins for different Arduino versions.

The 328P uses the following pins for hardware SPI:

/CS    Port B Pin 2    (Arduino pin 10)
MOSI   Port B Pin 3    (Arduino pin 11)
MISO   Port B Pin 4    (Arduino pin 12)
SCK    Port B Pin 5    (Arduino pin 13)

I used Timer 2 to drive the fade clock on the strips. The output of Timer 2 uses the following pin:

TIMER2 Port B Pin 1    (Arduino pin 9)

The strips themselves have the following labelling on the inputs:

S-I    Fade clock input
D-I    Data input
CK-I   Data clock input
L-I    Data latch input

So you need to wire up the strip as follows:

ATmega      Strip
/CS     to  L-I
MOSI    to  D-I
SCK     to  CK-I
TIMER2  to  SI

Note that if you want to wire up more than one strip you'll need to work around the fact that the HL1601 strips don't implement the SPI protocol properly. The easiest way is to gate the SCK signal with the /CS line so that when a strip is not being accessed it doesn't see the data clock. I've detailed the problem and the solution more fully in this earlier post,

Categories : Tech, AVR

I'm wheely pleased...

Last night I met up with Andy and Colin of The Travelling Light Circus at MadLab to finally finish off some the LED strips that I've been working on for so long. The original plan was for them to be worn, which would have meant splitting the 4 20-LED strips connected to each strip driver in half, to allow for bending at knees and elbows. That would have meant doing an additional 32 joints, so when they said they'd come up with an alternative way of mounting the strips I was not at all unhappy :-)

Andy managed to source some translucent plastic tube that the strips slide neatly inside. The tube does two things, it protects the fairly fragile strip from damage and it also diffuses the light from the LEDs to increase the viewing angle and provide a nice glowy effect. Andy and Colin's plan was to mount a box to contain the strip driver on the hub of a bike wheel and to then attach the four tubes + LED strips to the wheel as if they were 'umbrella spokes' - the picture below makes the setup clear:

LED wheels

Will of TLC fabricated a really good mounting for the box, and the batteries and strips were simply attached to the bike wheel with cable ties. The wheel itself is mounted onto a large diameter aluminium pole, attached to the wheel where the gears would normally be. The really neat thing is that because Will used rear bike wheels he could keep the freewheel mechanism in place, so simply 'flicking' the aluminium pole sets the whole thing spinning. Of course having got them finished, we had to have a play :-) The first video was taken inside the MadLab building by Sam from Girl Geeks when we had the first wheel finished.

The second video is with two wheels and was taken outside MadLab on Edge Street, just across from the Common bar and we caused quite a commotion, with people coming out of the bar to see what we were up to. As you can see from the video, the patterns on both wheels are synchronised. The slightly wobbly video is because I was filming and operating the radio controller for the strips at the same time - you can hear the switch clicks on the audio as I'm changing the patterns. And I love the obligatory enthusiastic American on the video soundtrack - "Awesome!" :-)

Categories : Tech, AVR