Pool water light show... question about audio input levels

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DuaneB
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Joined: Tue Jan 03, 2017 7:25 pm
Real Name: Duane Benson

Pool water light show... question about audio input levels

Postby DuaneB » Tue Jan 03, 2017 7:48 pm

Hi... I didn't know what DMX was last week, but I started a project to build some laminar water jets with built in light control for my inground swimming pool. I had already purchased a pi 3 and some arduinos with RS-485 shields with the idea that I would design my own protocol and write the software, but once I did a bit of research it seemed like DMX was a very well-matched protocol and it was perfectly compatible with all the hardware pieces I already purchased. So... in just a few hours, I had found QLC+ for the pi, had it installed on the pi, configured to talk over my RS-485 hardware and was controlling my LED lights that will eventually be embedded into a series of underground water jets that shoot illuminated water streams out of the walkway and into my swimming pool.

My overall design is a Raspberry Pi as the master controller with 6 water jets as fixtures. Each water jet will have an Arduino embedded and connected on an RS-485 bus. In addition to RBG LEDs on each water jet, I will also be building a "cutter" on each water jet that will chop the water stream as it flows to produce "segments" of water that fly through the air. I will also have a "knocker" on each water jet that simply bumps the jet to make a disturbance in the water stream that will reflect the light in the stream. So, in the end, each water jet will be a single fixture with RGB, cutter, and knocker capabilities. (Maybe these end up as three distinct fixtures per water jet... I'm still learning DMX).

Clear as mud? Here is a pic to illustrate the water jet...

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I have yet to add an acrylic rod through the center of the water jet, the LED's will be at one end of the acrylic rod, outside of the water jet housing, the acrylic rod acts as a light pipe that will project the LED light directly into the water stream as it exits the jet. With a perfectly clear water stream, the light will not be visible until it splashes down somewhere, or if the stream gets disrupted (by the knocker).

That's the water side... I'm still fine tuning this prototype jet, the water stream isn't quite perfect yet.

On the electronics side... here is QLC+ running on the raspberry pi, sending DMX data to my arduino which is using PWM on digital outputs to drive three LEDs. I am using a USB sound card dongle to receive an audio signal (from a chromecast, which is irrelevant, but cool).

https://drive.google.com/open?id=0B27Fb ... Tl0R2YtNDA

After all that... my problem is not even related to the water stuff, but thought some of you might find it interesting :-)

My "problem" is that the levels in an audio widget are very low and I'm working with 5%-6% triggers to get these lights to trigger. I am using a 30ms single shot chaser to get this effect and simply using the audio widget to trigger a cue for each color.

Is there any way for me to adjust the audio level on the USB sound card so that the audio widget has higher levels to trigger from? Currently it is volume dependent and I have to crank up the output from the Chromecast (which also feeds my audio amp) to get suitable levels to trigger the audio widget.

Since I'm an absolute newbie at DMX and QLC+, I'm open to learning new ways to accomplish an audio driven unattended light show (so we can just play music at the pool and have the lights chase with the music). However, I think I may also need to build some custom light shows in QLC+ to get the best effects from the combination of lights, cutters, and knockers that will be available on each water jet.
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fooschnickens
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Real Name: Taylor

Re: Pool water light show... question about audio input levels

Postby fooschnickens » Wed Jan 04, 2017 5:31 pm

That's quite the project!

Unfortunately the problem you describe is fairly well known. Windows users especially suffer from it though I've never fiddled with it on the Pi.

Since you're already using Arduinos in your setup, I'm wondering if you could task one inline with your audio feed to act as a trigger and send a signal to operate your chaser outside of the QLC widget.
DuaneB
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Joined: Tue Jan 03, 2017 7:25 pm
Real Name: Duane Benson

Re: Pool water light show... question about audio input levels

Postby DuaneB » Wed Jan 04, 2017 7:40 pm

Thanks for the feedback... I'm not surprised that this is a common problem.

I have thought about doing an FFT on an external device and sending it to QLC+ on the Rpi... maybe an Arduino, or possibly even with a PC. Arduino would be better since it keeps things self-contained without a full PC in the mix.

I'll keep experimenting. I've also ordered a new USB sound card (Behringer UCA222), but I don't expect this to fix the problem.
DuaneB
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Joined: Tue Jan 03, 2017 7:25 pm
Real Name: Duane Benson

Re: Pool water light show... question about audio input levels

Postby DuaneB » Thu Jan 05, 2017 2:52 am

Having fun learning and found a different approach for triggering on audio signals... I set up a lightjams installation on my pc, enabled the wifi on the Rpi and have lightjams triggering the lights over artnet while the RPi is still running QLC+ and bridging the artnet to DMX network.

https://drive.google.com/open?id=0B27Fb ... TRUaTVkWEk
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fooschnickens
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Real Name: Taylor

Re: Pool water light show... question about audio input levels

Postby fooschnickens » Fri Jan 06, 2017 1:28 am

DuaneB wrote:Thanks for the feedback... I'm not surprised that this is a common problem.

I have thought about doing an FFT on an external device and sending it to QLC+ on the Rpi... maybe an Arduino, or possibly even with a PC. Arduino would be better since it keeps things self-contained without a full PC in the mix.

I'll keep experimenting. I've also ordered a new USB sound card (Behringer UCA222), but I don't expect this to fix the problem.

I tried using that same device since I had it laying around for quick track recording for live shows in case the performers wanted it. I was able to get slightly better results since I could really up the gain on it, but since the signal was so distorted at that point it was a case of (quickly) diminishing returns. I had the best results putting the audio signal through a crossover so that only the lower frequencies would come through and then cranking that as far as I could. Worked decently well for some so-so beat matching, but required routing the signal through our effects rack and I doubt you want to add any more devices than is absolutely necessary.
DuaneB
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Joined: Tue Jan 03, 2017 7:25 pm
Real Name: Duane Benson

Re: Pool water light show... question about audio input levels

Postby DuaneB » Fri Jan 06, 2017 5:44 pm

I'm fairly impressed with the combo of lightjams and QLC+ working together... Lightjams seems much better suited to audio triggered light shows, but it seems to lack the customization and ability to build shows that QLC+ provides. I want both.

For the purpose of my residential pool light show, I think I'll stick with this combo for now... it does introduce a PC into the mix, but since it's all WiFi from the PC perspective it's pretty easy to make the Pi/Arduino setup a permanent installation, then just fire up the PC when I want to do audio triggered displays.

I've done a bit more work on my water jet "fixture"... added an acrylic rod up through the center of the jet to act as a light pipe to get the LEDs projected into the water stream...

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