Hey guys, long time no see! I fell out of the laser hobby for a long while, but I still kept a good bit of stuff around to tinker with!
5 years or so ago, I bought LSX basic and a RIYA Lite DAC from DrLava IIRC. I grabbed a super cheap set of "15kpps" galvos, too. Never got very far with it, fudged a lot of cheap green pointer modules trying to make them modulate, blew up a flex drive or two, then gave up. I recently discovered the uber-cheap e-bay RGB modules, so I picked up the cheapest TTL one I could find. I figured I'd play around with this, then maybe start upgrading things as I go. There are so, so many new to me diodes to play with. I'm especially stoked over the easy and cheap analog greens... Anyway, what I've got works rather well for what it is. I've limited the scan angle to around half using the RIYA settings program, then I can scale down in LSX and actually manage sharp corners at 18k or so! I have no idea what my actual scan angle is, but ILDA pattern is less than a foot wide at 6 feet or so, so it's not much at all.
All this is fine and good, but I'm having a strange output lag problem. The show will uh, show, fine in the preview window but the output will hang on a frame, then skip a few to catch back up. It's not a slightly discernible thing, there's times where it's gotta be playing less than a frame per second. The PC I am using should be up to the task (4770, 8GB, R9 290x) but it does seem to be CPU dependent. I can run youtube and realtime together and pretty reliably get the lag issue, but other times it will power through it just fine with no lag. I'm not trying to display too many points, either. One show that will lag pretty reliably is the wave expression demo show (test_live_audio_scope.rtd) Turning OpenGL rendering off seems to help a little, but the lag will still be there. I'm using a USB2.0 port directly on the motherboard, and while I can't disconnect all USB stuff I've pulled everything but the keyboard and mouse with no improvement.
My RIYA is old enough that it has the USB plug problem, but I don't think it's a physical connection issue. Sometimes I have to plug the thing in once or twice to get it recognized, but wiggling the USB connector once the connection is open/show playing does not seem to cause the lag directly. I just found out about the connector issue searching up a fix for this problem. Besides a non-lite ethernet multibus dac, I haven't been able to find anyone else with this issue besides a German forum mentioning "i" series processors missing some old processor commands or something along those lines. I'm not too sure that sounds right, pretty sure i series was a thing when LSX released?
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I don't have any other non i7 computers to test, and if I did I'm not sure my license from this PC would transfer anyway. The RIYA is supposed to be a dongle, but Drlava needed what looked like a hardware id generated number for my specific computer. Should I e-mail DrLava for any new updates? I think my version is current up through 2014 or so.
I guess my question is, is this a hardware limit of my cheap DAC or am I experiencing some other issue? My understanding is it's capable of 50kpps, so I can't be trying to display things too complicated? I don't have many (any) ilda files to test other player software, and the RIYA test program only lets me draw a frame at a time, so it's no good for checking lag. I guess that's what I'll probably try next, that or exporting a show to ILDA. I can do that, right?
Thanks guys!