Topic: Discussion on blanking timing adjustments and new EzAudDac 1.08 version

[drlava]

Yes, ok.  So now that that's straight, let's get back to the subject of in what state a frame should be sent to a controller driver, and what a controller driver should do with that frame.  If the frame is known to be pre-optimized such as the dolphins sequence, it should sent to the controller driver as-is.  The controller driver then takes it and applies the neessary blanking delay because it has been set up previously to work with the DPSS rig that it is driving.  What you get out, whether it is the dolphins frame or the ilda test frame, is a proper-looking frame.

[James]

I think the issue is where you find the intelligence that can, if necessary, make two distinctly different modifications to the stream of data that eventually gets clocked out the DAC to become a set of analog signals.

1. points optimization

2. color to scanner time alignment

If you do it in the driver, then you need to know how to tell your driver what to do, when.

If you do it in the preparation of a wave, then it might be well noted in the header of the wave.

You can't expect to set standards on how this is done!

This is the very art of it!

It is what makes one system better than others.

It is also what leaves it open to infinite future possibilities!

James. 

[drlava]

Yes, I was only suggesting that #2 be done in the driver/controller, as it is well suited for it.  It doesn't need to be told what to do, it will do the alignment all of the time.  The alignment tuning could be done with a set-up program (using the ilda test frame) just for the driver itself.  Once it's set, it can be forgotten!

[James]

Absolutely! 

Once I figured out that my PCAOM is about 7 samples @ 48KHz ahead of my galvos, that has remained a constant in my universe!

However, your universe may vary; hence the ability to adjust for such an anomaly.

James. 

[James]

There is a related issue that I saw at SELEM.

300Evil's RGB was weird on the green.

I think the rise time was just too long.

It was really strange. Sometimes the green was there and you could see white (not magenta!) and other times it looked like there was no green there at all.

I think that is something that could be compensated for in software, but should probably be corrected with a better laser diode driver.

Sample shifting won't fix this issue.

This is a matter of rise time, and how hot the diode is when it is asked to come on again. This is a much more complex issue of thermal hysteresis (I think).

James. 

[James]

I was only suggesting that #2 be done in the driver/controller

Eeeiiiiiiwwww !!!

James. 

[drlava]

if you have downloaded 1.08, download it again as there has been a bugfix fir the single frame writing function.