HELIOS DAC CHOP Intensity Issue

Hello TD community ! First of all thanks to everyone and the devs, first post around here :slight_smile:

I’ve been playing around with the Helios DAC on Touchdesigner, using the matching CHOP, but I did meet some issues.

Using a pinout board and my multimeter to test each pin output of the Helios DAC while I was playing with all the settings I’ve noticed that the Intensity setting seems to be broken and could be resolved.

From this issue " Helios DAC Issues " the problem seems to have been dismissed but it could in fact be quite useful to correct this feature.

According to my measures and tests I’ve noticed the following :
Measuring output pin n°3 matching Intensity according to ILDA specs

When feeding x,y,r,g,b channels to the Helios CHOP : ouput pin3 is always at 5V, max high, no matter the value for the “Intensity Scale” parameter and the 5 channels

As soon as feeding 6 or more channels in Helios CHOP, then the pin3 goes to 0V, low

I would think I could feed an " i " channel and match that intensity pin, but no matter the value of the 6th or 7th,… the pin3 value would stay at 0, no effects… BUT it actually matches the BLUE value
So let’s say I change the value of the ‘b’ channel to 1, the blue pin °7 of ILDA would output 5V as it should, and the pin3 also goes to 5V…
So it is now matching the BLUE channel instead of the possible 6th ‘i’ channel
AND I can now adjust the Intensity Scale in the Helios CHOP parameter and it does in fact really scale the intensity value independently from the blue output

Now I could really use that Intensity signal output from my Helios DAC and I really hope there could be a quick fix for that in the future.

Also regarding that Intensity, I really think it should behave the same as other colors channels and let the user match the value he wants to send through that other output.

Quick Edit: According to the doc of Helios : there are 4 DACs for RGB + Intensity

  • Max sample rate: 65.5 kpps
  • X/Y resolution: 12 bit (4095×4095)
  • Color and intensity resolution: 8 bit (16 million colors, not including intensity)
  • Shutter signal control

So also Shutter Signal seems to be missing

THANK YOU :slight_smile:

Thanks for the summary and ‘quick edit’ at the bottom which is most useful. We’ll look into this as soon as possible but there are some logistical issues right now getting access to the laser for testing so it might not be immediately. Thanks for your patience.

Thank you Ben for your reply!

No problem for the delay, as long as the issue has been noted and will be fixed at some point in the development this will be awesome!

Also I have to add a final note regarding the Helios DAC CHOP, the X Scale and Y Scale parameters seem to be broken also.
Compared to the X Scale and Y Scale parameters of the Laser CHOP, the Helios DAC Chop doesn’t seem to scale the x and y channels at all, in fact, it has quite a strange effect on the x/y output signals of the Helios, looks like some sort of translate but I’m not sure.

This scaling issue is not the most important because it can be adjusted with the Laser CHOP or some other math scaling, but I have to admit that fixing the 4th DAC channel would be the amazing fix the Helios CHOP has been missing :slight_smile:

Thanks again! Would be glad to help if you need anyone with access to the Helios DAC and a LASER Projector and a Multimeter to test the 4th DAC output :wink:

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