Soon starting Open source low cost RGB laser dac. Need input

[james]

LaserBoy creates waves with RGB+I and I can be caculated as a simple average, a color weighted average or a bitwise OR. Bitwise OR actually makes the most sense because when any one color channel is full on I is full on.

LaserBoy also supports color re-scaling tables. You can make an ASCII text table of 256 positive, even, 16 bit (14 bit) numbers, (first one must be zero, no repeats) for any one or all of the color channels including I, and LaserBoy will save that in the header of the wave and use it as a lookup table to translate the 0 to 255 values that come from the computer's RGB+I values. Since the numbers are all unique per channel, the process can be reversed when loading the wave back into LaserBoy.

The reason the numbers must be even is to leave the least significant bit open for marking ends of frames and re-scanned frames.

LaserBoy is also Open Source!

James.

[macpod]

This is a very interesting project, keep up the good work!

I'm still here, just waiting for more feedback before doing schematic entry and layout. Even if it's just a "yea, these specs and connectors seem ok with me" response


In the meantime I'm working on making some open source p-channel high-side drivers and possibly some tec drivers too. I'd love for these things to exist already, but haven't found anything.

[chad]

How about a review of what you have planed.

chad

I'm still here, just waiting for more feedback before doing schematic entry and layout. Even if it's just a "yea, these specs and connectors seem ok with me" response


In the meantime I'm working on making some open source p-channel high-side drivers and possibly some tec drivers too. I'd love for these things to exist already, but haven't found anything.

[macpod]

It hasn't changed since post #3, but I do know some component values I will use so..

Specs:

• usb
• Small
• low cost
• only up to 64kpps speeds
• 12 bit XY channels (differential, standard ILDA specs [e.g. x+(-5 to +5v), x- (-5 to +5v), gnd]) Tuneable via on-board pots.
• 12bits of Intensity control (not broken out, this connects to the analog laser dac for scaling). If SW doesn't support it, it is maxed.
• 12bit channel for ???? thoughts on use?
• 4 analog laser channels 0-5V (single ended, non-differential) 8 bits, but possibly slightly higher if price is neglegible on components.
• 5v TTL Interlock A (output) and B (input)
• breakout pins if convenient.. but probably not 0.1" headers since those take up lots of board space and make routing more difficult on 2-layer boards.
• mounting holes
• no ilda connector
• Serial number

Technical

• Will use LPC175x series chip. These will allow users to easily update/program the chip without a programmer and provide me with 1024byte usb iso transfers.
• Will have SWD header
• WILL NOT have dedicated i2c, spi, etc breakout headers. Instead I will just try to breakout all the lpc pins in a < 0.1" pitch header. This Hopefully will make "shields" easier to make
• Will use same 4 channel 12-bit dac as on the lasershark
• May use surface mount version of +/-12v power supply instead of through-hole to save automated assembly costs.
• Will use same x/y driving circuit
• Will use same rgb laser channel color circuits.
• Will have 4 leds (usb, power, usr1, usr2)
• Will have two momentary push buttons (RST, PGM)

[mrfloppy]

so its a DAC and controller card in one?

if so, this sounds much like a device i would want if price is right

[macpod]

so its a DAC and controller card in one?

if so, this sounds much like a device i would want if price is right

What do you consider a DAC and what do you consider a controller card?

[mrfloppy]

What do you consider a DAC and what do you consider a controller card?

DAC = the device between a laser projector and PC (usually USB or RJ45)
controller card = the card converting the signals from DAC into TTL/analog modulation and galvo steering


greetz
Mrfloppy

[macpod]

DAC = the device between a laser projector and PC (usually USB or RJ45)
controller card = the card converting the signals from DAC into TTL/analog modulation and galvo steering


greetz
Mrfloppy

In my mind, those are always the same thing. Do you have examples of where the DAC and controller card are different units?

The components should be:
Computer->Usb DAC (aka showcard)->([laser ttl/analog input] and [differential galvo input lines])

[mrfloppy]

yes, my laserworld projector has a small controller card that handles auto audio and DMX IDLA inputs, my DAC only converts USB to ILDA / easylase
using a dip switch on the back i can switch from ILDA to DMX or AUTO/Audio

but i see this has both the functions, so i think ill like it, if price is good enough,

[mixedgas]

In my mind, those are always the same thing. Do you have examples of where the DAC and controller card are different units?

The components should be:
Computer->Usb DAC (aka showcard)->([laser ttl/analog input] and [differential galvo input lines])

Ah, he's been a victim of sound card DACs where you need the level shifter board. The scars will heal in time. ;- 0

Steve