Having a fun Sunday afternoon play my harp (Laser harp that is.)

[Lasermad]

All looking good , enjoyed the vid !

paul

[stanwax]

As regards the colour mix... Couldn't you feed the figures into that program... Err... What's it called?.... Begins with 'C' I think

JEM!!!! Stop it now.

Rob

[Jem]

HeHe...

I needed a good chuckle today. It's funny how one mention of the 'C' word can make me smile .

[stanwax]

Ya swine Jem - you know how to push that button

Rob

[dash8brj]

Thats amazing. I nearly had tears in my eyes watching this.

How does the laser harp communicate the notes to the keyboard - do the beams bounce of the mirrors up top, which may be partially silvered, with an LDR behind, or is your harp the stephen hobley design with a sensor on the floor in front of the harp? I noticed it did the fan opening effect so I'm guessing the S H design.

Very impressive. I like JMJ, and the laser harp pieces are my favourite (Rendezvouz and Oxygene)

[Stoney3K]

Thats amazing. I nearly had tears in my eyes watching this.

How does the laser harp communicate the notes to the keyboard - do the beams bounce of the mirrors up top, which may be partially silvered, with an LDR behind, or is your harp the stephen hobley design with a sensor on the floor in front of the harp? I noticed it did the fan opening effect so I'm guessing the S H design.

Very impressive. I like JMJ, and the laser harp pieces are my favourite (Rendezvouz and Oxygene)

From what I've read on the YT description, the sensor mechanism is LDR-based with mirrors, probably partially silvered so the LDR's can pick up transmitted light.

The harp itself can still be scanning, as long as you do some compensation for the beam timing (or just add a huge low-pass filter) on the LDR's outputs you should have no problem there.

The LDR way is more straightforward, but it has a few limitations (requires mirrors, has a fixed number of beams). With the setup you have, it's not difficult to change to Stephen Hobley's design later on.

I have to agree, this needs some 445 with it. Maybe some 650 as well later on, I would love to see one do white.

[Carl B]

From what I've read on the YT description, the sensor mechanism is LDR-based with mirrors, probably partially silvered so the LDR's can pick up transmitted light.

The harp itself can still be scanning, as long as you do some compensation for the beam timing (or just add a huge low-pass filter) on the LDR's outputs you should have no problem there.

The LDR way is more straightforward, but it has a few limitations (requires mirrors, has a fixed number of beams). With the setup you have, it's not difficult to change to Stephen Hobley's design later on.

I have to agree, this needs some 445 with it. Maybe some 650 as well later on, I would love to see one do white.

The mirrors attached to the cross bar are nothing more than plexiglass. I have found some nice but cheap 50mm round dichros to replave the plexiglass that reflect most of the beam but lets enough light pass through to trigger the LDR's. These will also filter out a lot of ambient light. Even though the beam's are scanned the LDR's still work quite well.

The beams are created using Pangolin Live Quick. There is no blanking so when I tell LQ to output at 0% scan angle I get the one straight beam. Then to open the harp beams I just slide the size bar over to 100%. The laser is switched on & off with a key switched 5v supply.

I hope this makes the working of this harp a bit clearer