Laserharps Pre-order!

[csshih]

Dan's had some spotty 'net connection so I'll see if I can get in touch with him


Craig

[dnar]

Thanks. More questions.

At some point yesterday I had "Calibrating..." on the LCD, but I am not sure how I managed to get into this mode. There is an almost total lack of "user documentation" for the software. Can you provide this please?

Also, using a 300mW 445nm laser, I have found the whole detection system to be very poor. I would love to see the schematic and software as I am sure I can improve this substantially. Question: is the software sampling the ambient light level just prior to enabling the laser modulation, then looking for a delta once the laser is on?

As it is this will be useless for what I have planned.

PS.When the harp is closed, the scanner is "parked" at full deflection. I would like to change this to be "centered" (less heat).

The modulation looks less than ideal on my DSO. The modulation signal could be enabled for each beam much sooner than it is also, visible power is being lost. This could be a user tunable.

Also, per bank MIDI channel definitions would be great, so I can change "instrument" not just notes....

Another issue I have noted, the beams get brighter when triggered, this tells me the main line code is doing most of the work and the modulation is extended due to additional processing. I would have implemented this with a timer interrupt routine to produce the scan and modulation signals... Out of interest, does the code use the Arduino boot loader and DigitalWrite routines, because that IO method is SLOW!

This is one "kit" that access to the code and schematics would be great, as I am willing and able to improve this quite substantially. I see no need to protect any IP here, as it's not about the money right?

I am getting closer to simply reverse engineering the schematic and writing better code from scratch...

[Things]

Thanks. More questions.

At some point yesterday I had "Calibrating..." on the LCD, but I am not sure how I managed to get into this mode. There is an almost total lack of "user documentation" for the software. Can you provide this please?

This is kind of a useless mode, I was intending to remove it from the latest firmware but forgot about it.

Also, using a 300mW 445nm laser, I have found the whole detection system to be very poor. I would love to see the schematic and software as I am sure I can improve this substantially. Question: is the software sampling the ambient light level just prior to enabling the laser modulation, then looking for a delta once the laser is on?

The software should never see any ambient light level, as the opamp circuitry is designed to only detect quick pulses of light. Using it under LED or fluorescent lighting would be an issue here, there isn't really much yo can do about that other than putting wavelength pass filters on your sensors and avoid using lighting of that colour (If you're on stage, for example).

Then again, 300mW of 445nm really isn't all that bright. The sensor is fairly centered around green for best detection, there is a good chance you simply don't have enough light for a solid reflection.

As it is this will be useless for what I have planned.

Seeing as I haven't done any more runs on these, you could easily sell it again for what you paid, if not more now that it's assembled.

PS.When the harp is closed, the scanner is "parked" at full deflection. I would like to change this to be "centered" (less heat).

I have noticed this too, and am looking at ways of dealing with it.

Also, per bank MIDI channel definitions would be great, so I can change "instrument" not just notes....

Have been planning on adding this functionality, however no one has really bothered asking for it so I put it on the backburner for a while.

Another issue I have noted, the beams get brighter when triggered, this tells me the main line code is doing most of the work and the modulation is extended due to additional processing. I would have implemented this with a timer interrupt routine to produce the scan and modulation signals... Out of interest, does the code use the Arduino boot loader and DigitalWrite routines, because that IO method is SLOW!

Correct, however the harp does already use timer and hardware interrupts. The issue here is we only have 1 core to work on, and sending the MIDI messages are what takes the largest amount of time in the code.

Yes, it does use the Arduino bootloader, however it uses portmapping instead of digitalWrite for better speed.

This is one "kit" that access to the code and schematics would be great, as I am willing and able to improve this quite substantially. I see no need to protect any IP here, as it's not about the money right?

Not so much the money, but the fear of my work being leaked. I have been very reluctant to share the code as I have spent many days and nights working on it, and I'd hate to see someone just spreading it around. It also means I'd get constant messages asking why their DIY system isn't working, how to fix the code, what the code does, explain the code step by step etc etc. Much easier if I know the hardware everyone is working with, thus why I ran these kits.

I am getting closer to simply reverse engineering the schematic and writing better code from scratch...

If you feel you really need to, go ahead, but I've never had anyone bring up the requests/issues you are, so there was never any push for me to change it.

If you can write out a complete, straight to the point list of what you want/want changed, I'll look into it. I have some spare time coming up I could deal with it in.

[dnar]

Thanks. So no chance of getting the source under an nda? How about I send you my code changes and you continue to release with my improvements?

I am offering you code improvements by someone with years of embedded real time experience.

You didnt reply to question re ambient sampling ?

[Things]

I've sent you an email.

Dan

[Carl B]

Hey Dan, If you and Dnar start collaborating together to improve the code for the laser harp kits will others who have bought them benefit from this collaboration?

I am very happy with the way my kit is working now but any improvements can only be good thing, right?

[Things]

You bet

Dan

[dnar]

Ok, I have made some improvements to the electronic design and re-written the code pretty heavily, it's working pretty well now and is truly Polyphonic (not really before). Here is a quick demo, I'll post more details and photos on the weekend.

[taggalucci]

Nice looking green you got there Wayne

[Carl B]

Ok, I have made some improvements to the electronic design and re-written the code pretty heavily, it's working pretty well now and is truly Polyphonic (not really before). Here is a quick demo, I'll post more details and photos on the weekend.

I take it this not just an update to the code but also physical changes to the harp PCB as well?

Carl