May I start a laser harp build thread?

[Squonk]

Looking at that schematic I see that the LM7906 has pins 1, 2 and 3 listed as Vin, GND and Vout, the same as the LM7806. This may be wrong.

Thank you, Neil! This completely solved the problem of the -6V output. Unfortunately, though, the +5 and +6 that were working before I rewired the last regulator are now both giving me +3.5 V. I'm hoping that fixing one part of this circuit didn't break the others.

[Carl B]

I've down loaded the plans for the frame-less laser harp of Stephen's.
Obviously some code is needed for the control of the galvo and the sensor. Is this code part of the downloaded file or do we have to copy it from the .pdf and what equipment is needed to copy the code to the circuit.

Reading though the .pdf it is very obvious that Stephen put a lot of work in to the design for this harp.

Carl

[Squonk]

I've down loaded the plans for the frame-less laser harp of Stephen's.
Obviously some code is needed for the control of the galvo and the sensor. Is this code part of the downloaded file or do we have to copy it from the .pdf and what equipment is needed to copy the code to the circuit.

Reading though the .pdf it is very obvious that Stephen put a lot of work in to the design for this harp.

Carl

The pdf plans that you buy include a text document with the Arduino code.

[Squonk]

Got it sorted. The other problem I was having came from not having the common wire grounded well.

Now on to the second stage. I'm sure I'll be back hat (or soldering iron) in hand soon.

[Squonk]

Managed to get through the first part of the harp circuitry this weekend and am now looking at 10 nice green harp strings on my dining room ceiling. I'm sure there are more challenges ahead, but this is really encouraging!

[Carl B]

Great to hear you are making progress with the harp.

I take it you are driving the scanner with a differential signal. The reason I ask is because I have a spare set of 10k scanners but the signal input is only single ended. If these scanners are up to the job then it seems I have most of the main hardware needed to build a frameless harp.

The big stumbling block for me will be the electronics as I'm OK with basic circuits but beyond that and zero experience with any form of computer code programing I'm a bit stuffed.

Would like to see photo's as we like looking at photo's here on PL, especially of people building projects.

Carl

[stanwax]

Hey Carl
Im not far away if you need any help with the elecronics side

Rob

PS I will give you a bell later about next weekend

[Carl B]

Cheers Rob.

When I get round to starting this rebuild of my harp, I'll just be going for the basic Mk1 setup without the Wii remote and will be using my hot 150mW CNI green laser that's doing about 250mW.

I've not read the PDF in full yet but is it possible to assign beams to any note on a keyboard or are they preset to a defined note? The ability to change the note assignment is a must for me.

May be looking at a new project to get finnished ready for UKLEM 4 in Feb. And bash everyone's ear's with some J M Jarre again.

Carl

[Squonk]

I take it you are driving the scanner with a differential signal. The reason I ask is because I have a spare set of 10k scanners but the signal input is only single ended. If these scanners are up to the job then it seems I have most of the main hardware needed to build a frameless harp.

The big stumbling block for me will be the electronics as I'm OK with basic circuits but beyond that and zero experience with any form of computer code programing I'm a bit stuffed.

Would like to see photo's as we like looking at photo's here on PL, especially of people building projects.
Carl

Hi, Carl. The input to the scanner (one motor from a Scanpro20 set) is S+, S- and ground, so I guess I am using a differential signal. I'm in the same boat with you when it comes to circuitry, though, and might not know what I'm talking about here. Steve Hobley mentioned somewhere on his forum that he thought 10K scanners might be acceptable.

The plans Steve sells come with code for the Arduino, so if you can figure out how to upload it to the chip, you're pretty well set. I'm hoping to modify the code to give me 12 "strings." I think the strings are assignable to just about any note. As you noted, Steve has also modified his harp to use a Wiimote for sensing the position the hand (via the reflected laser light) in space. If I get to the point where I can integrate that, I'm thinking I could use it to tell the harp which octave to play based on how high on the "string" the hand breaks the beam.

Will try to post a pic or two soon, but am a little leery about the amateurishness of my circuit building.

[Things]

10K should be fine, afterall, its only drawing a single line!

And yes, please post pics as you build your project I know I and alot of other people like to watch these things get built