LASER Harp

[G Bulmer]

After the meeting, I did a quick google, and found:
http://www.make-digital.com/make/vol15/?pg=67
http://www.make-digital.com/make/vol15/?pg=69
http://www.make-digital.com/make/vol15/?pg=71

I have that issue of the Make Magazine too.

It is a midi controller, and uses an Arduino.

It starts off by making a LASER Theramin.

GB

[G Bulmer]

On Aug 29, 12:52 am, G Bulmer <gbul...@gmail.com> wrote:
> After the meeting, I did a quick google, and found:http://www.make-digital.com/make/vol15/?pg=67http://www.make-digital.com/make/vol15/?pg=69http://www.make-digital.com/make/vol15/?pg=71

>
> I have that issue of the Make Magazine too.
>
> It is a midi controller, and uses an Arduino.
>
> It starts off by making a LASER Theramin.

Ooops, should have posted this too, by the same person as the Make
article:
http://www.stephenhobley.com/build/

GB

[hellocatfood]

I'd certainly like to start building this! Looking at the materials
list do we have any those?

Ant

On Aug 29, 1:25 am, G Bulmer <gbul...@gmail.com> wrote:
> On Aug 29, 12:52 am, G Bulmer <gbul...@gmail.com> wrote:
>

> > After the meeting, I did a quick google, and found:http://www.make-digital.com/make/vol15/?pg=67http://www.make-digital....

[G Bulmer]

On Aug 31, 10:38 pm, hellocatfood <bv3...@gmail.com> wrote:
> I'd certainly like to start building this! Looking at the materials
> list do we have any those?
>
> Ant

I have 5 low-cost micro red laser modules from Odicforce:
http://s243333424.e-shop.info/shop/article_OFL85/Micro-Red-Laser-Module---5-Pack.html?shop_param=cid%3D13%26aid%3DOFL85%26

They need to be driven by a current limited supply (a resistor will do
to start), and an Aduino can drive it. It needs to be kept below 1mW
so that eyesight isn't easily damaged.

According to stuff on the net, less than 1mW is 'okay' because a
normal person blinks quickly enough to avoid eye damage.
This all seemed a bit dodgy to me, so I got red LASER SAFETY GOGGLES:
http://s243333424.e-shop.info/shop/article_OFL149/Laser-Safety-Goggles-EP2-Protected-Wavelength%3A-200-380nm-_-600-760nm.html?shop_param=cid%3D6%26aid%3DOFL149%26

If green LASERs are used, the guy who runs Odicforce said they should
have Infrared filters too; he said green LASERs emit a lot of
Infrared, which they eye does not respond to by blinking, so be
careful. Odicforce sells green LASER SAFETY GOGGLES too:
http://s243333424.e-shop.info/shop/article_OFL52/Laser-Safety-Goggles-EP1-Protected-Wavelength%3A-200-540nm-_-800-2000nm.html?shop_param=cid%3D6%26aid%3DOFL52%26


The laser Harp in the article uses six Sharp GP2D12 or GP2D120 IR
range measuring.
This is actually the 'guts' of the instrument. It measures distance
to, for example, your hands. This works whether or not their are
lasers.
The lasers are really showing you where to put your hands, and the
range measuring sensors do all of the work to figure out how far away
your hand is.

The cheapest places to buy those sensors that I've found are (USA) at
about $8 + P&P etc:
http://www.junun.org/MarkIII/Store.jsp
http://www.hobbyengineering.com/H1061.html
http://www.roboticsconnection.com/p-22-sharp-gp2d12-ir-sensor.aspx

UK (£8.40 inc P&P):
http://cgi.ebay.co.uk/Sharp-GP2D12-infrared-Sensor_W0QQitemZ220474148808QQcmdZViewItemQQptZUK_ToysGames_RadioControlled_JN?hash=item33554887c8&_trksid=p3286.c0.m14

Six would be about £50. A bit expensive for my school projects :-(

Those sensors look nice to use, they produce an analogue voltage to
represent distance. That would be fed into an Arduino analogue pin,
and a sketch reads that, and decides what note to play.I keep meaning
to try them for robotics. At least one of the micromouse guys have
used them.

One of the articles explains how to use an Arduino to generate MIDI
events, so, I imagine almost any midi instrument can be used.

I would suggest starting with a one-string "Theramin". Then all of the
basic electronics, and playing music gets solved using only one of
those distance-measuring sensors.

Once something is working, there'd be lots of room for experimenting
with different sensors, and ways to control the notes.

I am thinking a nifty solution might be a single laser scanned across
an arc using my 'mechanical TV' mechanism set up to work as a camera.
GB

[Michael Nicholls]

I did like the look of the laser harp.

Sounds like the "Theramin" is the perfect place to start it.

I remember you describing your 'mechanical TV' and since the lasers
are separate from the sensors then it sounds like a great way of
keeping cost down.
Would love to be involved if there is anything I can contribute.

Mike

On Sep 1, 1:38 pm, G Bulmer <gbul...@gmail.com> wrote:
> On Aug 31, 10:38 pm, hellocatfood <bv3...@gmail.com> wrote:
>
> > I'd certainly like to start building this! Looking at the materials
> > list do we have any those?
>
> > Ant
>

> I have 5 low-cost micro red laser modules from Odicforce:http://s243333424.e-shop.info/shop/article_OFL85/Micro-Red-Laser-Modu...

>
> They need to be driven by a current limited supply (a resistor will do
> to start), and an Aduino can drive it. It needs to be kept below 1mW
> so that eyesight isn't easily damaged.
>
> According to stuff on the net, less than 1mW is 'okay'  because a
> normal person blinks quickly enough to avoid eye damage.

> This all seemed a bit dodgy to me, so I got red LASER SAFETY GOGGLES:http://s243333424.e-shop.info/shop/article_OFL149/Laser-Safety-Goggle...

>
> If green LASERs are used, the guy who runs Odicforce said they should
> have Infrared filters too; he said green LASERs emit a lot of
> Infrared, which they eye does not respond to by blinking, so be

> careful. Odicforce sells green LASER SAFETY GOGGLES too:http://s243333424.e-shop.info/shop/article_OFL52/Laser-Safety-Goggles...

>
> The laser Harp in the article uses six Sharp GP2D12 or GP2D120 IR
> range measuring.
> This is actually the 'guts' of the instrument. It measures distance
> to, for example, your hands. This works whether or not their are
> lasers.
> The lasers are really showing you where to put your hands, and the
> range measuring sensors do all of the work to figure out how far away
> your hand is.
>
> The cheapest places to buy those sensors that I've found are (USA) at

> about $8 + P&P etc:http://www.junun.org/MarkIII/Store.jsphttp://www.hobbyengineering.com/H1061.htmlhttp://www.roboticsconnection.com/p-22-sharp-gp2d12-ir-sensor.aspx
>
> UK (£8.40 inc P&P):http://cgi.ebay.co.uk/Sharp-GP2D12-infrared-Sensor_W0QQitemZ220474148...

[G Bulmer]

On Sep 3, 2:07 pm, Michael Nicholls <nicholls...@googlemail.com>
wrote:

> I did like the look of the laser harp.
>
> Sounds like the "Theramin" is the perfect place to start it.
>
> I remember you describing your 'mechanical TV' and since the lasers
> are separate from the sensors then it sounds like a great way of
> keeping cost down.
> Would love to be involved if there is anything I can contribute.

I think we could quickly make a short-range distance-sensor from a
couple of ultra-bright LEDs, light sensors and white gloves.
I have all the parts except the white gloves.
We'd need to to hook up an Arduino (got one of them) to a midi-synth
of some kind (I haven't got one of those).
For simplicity we could drive a piezo-speaker with a tone controlled
by the distance sensor, just to see if any of it works, and take it
from there.

GB

[Michael Nicholls]

My Dad's company sells first aid and he sells rubber gloves (I think
they do white), so I could easily get hold of some if they would be
any good?

Mike

[nikki]

Rubber gloves would probably be quite unpleasant to wear after a while
(based on my experience doing science workshops!), doubly so if
there's any passing pairs between wearers to be done...

I'd go for cotton ones. Twitter says photographers use them a lot. You
can get them from boots (look a bit expensive), or even RS does
packets.
http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=3679429

Failing that, my skin's nice and pasty, I'm sure its reflective
properties are really very good :)

nikki




On Sep 4, 10:39 am, Michael Nicholls <nicholls...@googlemail.com>
wrote:

[Michael Nicholls]

lol i like the idea you can use the hard if you haven't been holiday
this year ;-)

Good point about the rubber gloves. Will find out if he is anything
similar to the cotton ones, although I doubt it.

Mike

On Sep 4, 11:31 am, nikki <genzai...@googlemail.com> wrote:
> Rubber gloves would probably be quite unpleasant to wear after a while
> (based on my experience doing science workshops!), doubly so if
> there's any passing pairs between wearers to be done...
>
> I'd go for cotton ones. Twitter says photographers use them a lot. You
> can get them from boots (look a bit expensive), or even RS does

> packets.http://uk.rs-online.com/web/search/searchBrowseAction.html?method=get...

[G Bulmer]

On Sep 4, 11:31 am, nikki <genzai...@googlemail.com> wrote:

> Rubber gloves would probably be quite unpleasant to wear after a while
> (based on my experience doing science workshops!), doubly so if
> there's any passing pairs between wearers to be done...

Hmm, that is not a pleasant thought ... :-(

>
> I'd go for cotton ones.

Yes.

> Twitter says photographers use them a lot. You
> can get them from boots (look a bit expensive), or even RS does

> packets.http://uk.rs-online.com/web/search/searchBrowseAction.html?method=get...
They are discontinued :-(
I'd be happy with 30p a pair!

>
> Failing that, my skin's nice and pasty, I'm sure its reflective
> properties are really very good :)

Nice :-)

I was thinking of white gloves for a few reasons:
1. Get a nice strong reflection, so cheap light sensors would work at
a greater distance,
2. Reduce the variability between players hands, so there would be
less set-up.
I thought this would be a nice improvement if we had visitors
playing it.
3. Looks quite deliberate, a part of the performance, like a conductor
putting on gloves.

GB

[nikki]

14p a pair?
http://cgi.ebay.co.uk/EPIC-WHITE-COTTON-GLOVES-SIZE-10-BRAND-NEW_W0QQitemZ260459251278QQcmdZViewItemQQptZMen_s_Accessories_UK?hash=item3ca494c64e&_trksid=p3286.c0.m14

> 3. Looks quite deliberate, a part of the performance, like a conductor
> putting on gloves.

s'all about the performance :)

[G Bulmer]

On Sep 4, 5:20 pm, nikki <genzai...@googlemail.com> wrote:
> 14p a pair?http://cgi.ebay.co.uk/EPIC-WHITE-COTTON-GLOVES-SIZE-10-BRAND-NEW_W0QQ...
My hero !-)
BTW, do you understand how glove sizes work? Any idea how big size 10
is?

>
> > 3. Looks quite deliberate, a part of the performance, like a conductor
> > putting on gloves.
>
> s'all about the performance :)

Absolutely!
Especially if you were forced to experience my "musical talent" :-(

GB

[nikki]

> BTW, do you understand how glove sizes work? Any idea how big size 10
> is?

hopefully like this: http://www.pricedright.co.uk/content/gloves.cfm

> > s'all about the performance :)
>
> Absolutely!
> Especially if you were forced to experience my "musical talent" :-(

Garry, meet Alfonso: http://www.vimeo.com/6415435

[G Bulmer]

On Sep 5, 9:16 am, nikki <genzai...@googlemail.com> wrote:
> > BTW, do you understand how glove sizes work? Any idea how big size 10
> > is?
>
> hopefully like this:http://www.pricedright.co.uk/content/gloves.cfm

Thank you!
So 10 is pretty big!
In retrospect, the bigger the better from a performance
perspective ...
"I am just going to put on my HUGE hands to play ..."

>
> > > s'all about the performance :)
>
> > Absolutely!
> > Especially if you were forced to experience my "musical talent" :-(
>
> Garry, meet Alfonso:http://www.vimeo.com/6415435

Impressed! That makes everything much clearer.
Alfonso does look very cute too.

GB

[G Bulmer]

On Sep 4, 5:20 pm, nikki <genzai...@googlemail.com> wrote:
> 14p a pair?http://cgi.ebay.co.uk/EPIC-WHITE-COTTON-GLOVES-SIZE-10-BRAND-NEW_W0QQ...

Ordered.

GB

[G Bulmer]

On Sep 4, 5:20 pm, nikki <genzai...@googlemail.com> wrote:
> 14p a pair?http://cgi.ebay.co.uk/EPIC-WHITE-COTTON-GLOVES-SIZE-10-BRAND-NEW_W0QQ...
>

> > 3. Looks quite deliberate, a part of the performance, like a conductor
> > putting on gloves.
>
> s'all about the performance :)

The £1.44 is for one pair, not 10 pairs.

Garry