Laserharps Pre-order!

[csshih]

does anyone else have reports on if they've got theirs working or not? We want to make sure everything works well before the second batch which is coming soon

Craig

[Carl B]

I have had mine built and working for the last week. I did take it to the UKLEM last weekend and managed to play a couple of Jarre tune's (Oxygene 7 & Chronologie 3) but there are some issues that still need sorting.

I have been in contact with Dan about slowing down the scan speed of the harp in the full open play position to match the scan speed of when it is opening / closing. The reason for this is to reduce the work load on scanners that are only rated 15 - 20kpps and to give DPSS lasers more chance to respond to the modulation. My 400mW Green laser looks to be doing only 40mW when the harp reaches the full open position.
I have been given details about how to do this but have yet to actually try changing some settings.
In non blanking mode the harp looks mega with the laser at full power and the sensor responds much better but the top (right) beam note also seems to be on most of the return stroke of the scanner. It's like the top note is not being clipped quick enough before the scanner returns to the bottom (left) beam. I do remember Dan saying that getting the harp to work properly in non blanking mode was a bit more tricky but maybe this could also be solved by just slowing down the scan speed.

The other thing is the midi note velocity when hitting a beam. I think I'm right in saying that Dan was to implement some ability to change this in an update of the note programmer but I would recommend that the default be set to 100. The upper limit being 127, when I am playing my keyboard the velocity I hit the keys is usually around the 100 mark so I think this should be the same for the harp.

Apart from the above I am really pleased with the kit. It went together well and work first time I powered up.

I will try and post some photo's and video of my harp when I get some more fog fluid. In the mean time here are some photo's of the harp, sensor and internals.


I'm hoping that I will be getting 2W's of blue to go with the green in the next few weeks. With 2W+ of power I am hoping that I will be able to reduce the value of the sensor pot. making the harp a lot less sensitive to ambient light.

Carl

[GoolGaul]

@ Dan.
Here is a web page that may be of use to you about MIDI protocol.
http://www.gweep.net/~prefect/eng/re.../midispec.html

According to this page there is a definite Note Off command that should be used to stop a note playing. This may explain the reason why I am getting a stuck note when the harp is opening.
Just changing the velocity to 0 technical dose not stop the note.

Edit : Just reread the web page above and it says that a note with 0 velocity is concidered as Note Off. Sorry for doubting you.

Carl

Sending a note with VEL = 0 vs. sending a NOTE OFF...

I think that the VEL=0 could be problematic for portamento and playing samples.
With a long release time or a 'free=running' envelope, a note can "survive" a NOTE OFF, but not a VEL=0...

Then again, if you turn VEL off in the sound, since they're all 100 anyway, it might not matter.

[csshih]

It's been quiet, but another run is in the works. This time it will be 30 kits.

Craig

[CJ9]

Hi Craig, a few questions I have:

Is the scanner controllable on an axis as a laser projector is (i.e. what resolution does it have)? Or is it programmed for just the beams?
Are the MIDI notes stored in the uC?
Does this come with any documentation about it? And do we get the source code, or a pre-programmed uC (and hex code)? For example, if I wanted to make some changes to the code to suit my needs etc.

Thanks!

[Things]

Q1. The kit outputs a voltage signal you just connect right to your galvo amps, as you would an ILDA signal.
Q2. Yes, they are stored in the uC's EEPROM.
Q3. Yes, it comes with an assembly manual (Emailed to you when the kits are shipped out). The source code isn't included, I've spent a LOT of my own time working on it for these kits, I'd prefer it wasn't leaked

However, my modifications included allowing you to modify any settings you should ever need to. You can look back a few pages and read a bit more about it.

[csshih]

quick update to all you waiting:

while my studies are keeping me a bit busy I hope to be able to ship in approximately 2 weeks (after testing/verifying the kits are good to send out!)

Craig

[Carl B]

I thought I would bump this thread with news about the latest version of code for these laser harp kits I have been testing along with Dan (Things).

This latest version of code (v2.45) has resolved the issue of the beams going very dim once they reach the fully open play position when operating with blanking mode on.
I got to test v2.43 at the end of last week and that was the version that had resolved the beam brightness issue but another blanking issue found it's way in to that version. I told Dan about it and with in two days this latest version of code was sent to me and in my opinion the code for the harp operating in blanking on mode (the preferable way in my opinion) is now perfect. This is with a 400mW laser. Lower powered lasers should work but the sensor pot will need at least a 200k resistor putting in line with it.

I did try the harp with the blanking off and this just overloads the sensor with light in the house making this mode unusable.
A dark or high ceiling may be the answer to this issue.

So anyone who bought a kit from the first run should be able to get a code update soon and I would think that v2.45 will be loaded in to the second run of kits.

A big thanks to Dan for his hard work in making these kits available and solving the issues with the code.

If you have ever wanted a laser harp then I would strongly recommend you get your name down for one of the second run of kits.
Ordering details are listed above in this thread.

Carl

[Things]

Hi guys, yes, as Carl has said, I now have upgrade packages ready for everyone that will let you upgrade your harps to version 2.45 of the code. The beam brightness increase will blow you away, I highly recommend upgrading. It also fixes a few other small internal issues.

Please send me an email at lpfthings[at]gmail[dot]com and I will send you the program and the instructions. Please include your forum username in the email

The 2nd batch of kits are underway, and should be ready to ship very soon, you can order from illuminationsupply as usual The new batch will ship with 2.45 default (Unless I encounter any more issues between now and then).

[csshih]

2nd batch is out! instructions to follow soon!

Craig