Laser Harp

[Adarsh Hasandka]

@Bhuvana: If you want to make this event even more cost effective, you could consider using the cheap Rs 20-30 laser modules and drive them with a TLC5916 LED driver IC. You can use an MSP430G2231 to provide the PWM signal as well as read all 8 photodiode inputs. If you want to expand the harp, you could involve some multiplexing/demultiplexing and stick with the MSP430G2231 or move to the MSP430G2553. total harp cost would come to around Rs 250 or so instead of 1250 in case of the lasertanks laser modules (Rs 150 each). Just an idea, look into it if you think it's worthwhile.

[pavan k shetty]

Arent those 20 buck lasers really hard to work on?The body cant be soldered on.They were a pain when we tried them in lasertanks.

On Mon, May 7, 2012 at 12:58 PM, Adarsh Hasandka <adarshh...@gmail.com> wrote:

@Bhuvana: If you want to make this event even more cost effective, you could consider using the cheap Rs 20-30 laser modules and drive them with a TLC5916 LED driver IC. You can use an MSP430G2231 to provide the PWM signal as well as read all 8 photodiode inputs. If you want to expand the harp, you could involve some multiplexing/demultiplexing and stick with the MSP430G2231 or move to the MSP430G2553. total harp cost would come to around Rs 250 or so instead of 1250 in case of the lasertanks laser modules (Rs 150 each). Just an idea, look into it if you think it's worthwhile.

--
regards
Pavan K Shetty

3rd Year Btech 

ECE

NITK Surathkal

[Adarsh Hasandka]

True, but if we can use them, they will make the event much, much cheaper... also we need not solder. Since we are going to be mounting them anyway, we can use some really good metal clamps, alligator clips.screws etc. I'm just suggesting that we should consider them.

[Bhuvana Bairy]

hey!

sorry, i couldnt reply earlier.

Amber wants to do laser harp yea? I think I'll be doing the levitating bulb thing. If she isn't interested, then I'll take it up :)

[Amber Afshan]

I'll do the laser harp thing :)

[pavan k shetty]

Someone should look into the sound generation in parallel. Its going to be important in terms presentation and will take some time. A number of different frequencies will have to be generated to get each note and play it using a speaker.

[Adarsh Hasandka]

Look at this:
http://en.wikipedia.org/wiki/Laser_harp
look at the different software modes present here,
On the audio side,
We could possibly interface this with an arduino synthesizer:
http://code.google.com/p/tinkerit/wiki/Auduino
http://arduino.cc/playground/Main/ArduinoSynth
Or we could emulate 8-bit sound using arduino:
http://arduino.cc/playground/Main/SID-emulator

[Bhuvana Bairy]

i had once calculated frequencies for a virtual piano project, i think i still have the values!

[Bhuvana Bairy]

or even better : 
http://www.phy.mtu.edu/~suits/notefreqs.html

the main one is A5, 440Hz. 

[Adarsh Hasandka]

Consider this option,
The msp would output the string number to the synthesizer, possibly an arduino. or it could perform the sound generation itself, though i doubt it has enough flash for the sound code.
with one TLC,74595 we can accommodate up to 8 strings, with two 16, and so on. If we choose to have more strings, I think we should definitely consider going for the cheap Rs20 laser diodes.
Regards,
Adarsh

[pavan k shetty]

Suggest using TLC 5940's since we are printing boards for them anyway.and btw both TLC5940 and 74595 use 3 inputs:sin,sclk and latch clock

[Adarsh Hasandka]

Good idea. TLC 5940 should be easy to use. The code will have to be changed of course, but this shouldn't be a problem.
@Amber: Can you come up with a rough design and budget of what you plan to do?

[pavan k shetty]

You could use the same inputs to the TLC and the shift reg,since they use similar inputs and expected outputs are the same.If MSP is a problem then an arduino could also be used for the whole thing.It has a library for TLC and shift registers.And sounds I think.

On Sun, May 13, 2012 at 3:00 PM, Adarsh Hasandka <adarshh...@gmail.com> wrote:

Good idea. TLC 5940 should be easy to use. The code will have to be changed of course, but this shouldn't be a problem.
@Amber: Can you come up with a rough design and budget of what you plan to do?

[Adarsh Hasandka]

yeah, just an arduino would also work.
@Amber: Consider this idea when you make your abstract/budget. I think with this we can easily accomodate 16-24 strings and make an insanely awesome laser harp.