General DIY LED thread

[Steven Garland]

Man that sucks... I'm sure you can find a BlueFish or a Storm used for cheap.

I mean shoot I just scored a BF Mini,NanoBox array,Nanobox PSU,7 ldd's,2 3up boards,and a bunch of loose leds for $55 shipped.

 

[AbjectMaelstroM]

Man that sucks... I'm sure you can find a BlueFish or a Storm used for cheap.

I mean shoot I just scored a BF Mini,NanoBox array,Nanobox PSU,7 ldd's,2 3up boards,and a bunch of loose leds for $55 shipped.

I really want to get this working with Reef pi as it is pretty much the only reason I went DIY, so an external controller is my absolute last ditch effort.

I want to know if there is a limitation on the Reef pi/PCA9685 or if im missing something. Hoping Ranjib, Mike or Theatrus can chime in with any ideas of where to start looking.

I don't know much in the are of led lighting/drivers/pwm so I don't have much to go on as far as diagnosis. Could be reef pi running out of steam pushing more than 5 channels?

 

[oreo54]

Maybe. Got a VOM to test the current/voltage out of the 9686 pwm wire?
LDD's require very little but ????
Current draw on the PWM wire does increase as you ramp up..

DISCLAIMER: A bit out of my pay grade here.. ;)
and pretty sure "someones" run 5 plus LDD's here..

you have a separate 5V ps for the 9685 board right?
https://learn.adafruit.com/adafruit-16-channel-servo-driver-with-raspberry-pi?view=all

 

[AbjectMaelstroM]

Maybe. Got a VOM to test the current/voltage out of the 9686 pwm wire?
LDD's require very little but ????
Current draw on the PWM wire does increase as you ramp up..

DISCLAIMER: A bit out of my pay grade here.. ;)
and pretty sure "someones" run 5 plus LDD's here..

you have a separate 5V ps for the 9685 board right?
https://learn.adafruit.com/adafruit-16-channel-servo-driver-with-raspberry-pi?view=all

Using @Michael Lane pi hat, powered by a 12v 2.1a plug, stepped down to 5v via buck converter.

I have a spare 15v 7.6 laptop PSU that I may gut and power the Reef pi. Though I doubt that drivers are taking anywhere close to 2A in PWM juice.

I will check volyage/current on the hat pins for the pca9685.

 

[AbjectMaelstroM]

Maybe. Got a VOM to test the current/voltage out of the 9686 pwm wire?
LDD's require very little but ????
Current draw on the PWM wire does increase as you ramp up..

DISCLAIMER: A bit out of my pay grade here.. ;)
and pretty sure "someones" run 5 plus LDD's here..

you have a separate 5V ps for the 9685 board right?
https://learn.adafruit.com/adafruit-16-channel-servo-driver-with-raspberry-pi?view=all

Reading 3.307v and 0.8mA DC on thr pwm pins at 100% in reef pi.

 

[oreo54]

Looks good to me.. I got nothing else here...
software related??

We’ll sort out the pwm frequency issue soon as we can, in case that’s something useful here

https://www.reef2reef.com/threads/meanwell-ldd-cree-leds-reef-pi-problem.561719/

 

[AbjectMaelstroM]

Looks good to me.. I got nothing else here...
software related??


https://www.reef2reef.com/threads/meanwell-ldd-cree-leds-reef-pi-problem.561719/

Yeah... I don't know anymore.

 

[oreo54]

Well till someone else shows up let's go here:
https://www.reef2reef.com/threads/meanwell-ldd-cree-leds-reef-pi-problem.561719/

If it is checked, try setting the brightness to 50% and measure the voltage on the output. Most meters will average the reading, so you should get around 2.5v.

Implies it should be 5V.. wrong?

anyways try adj the pwm frequency..

See images.. Suggest (for no good reason) "25" on the pi..

@Ranjib
In a nushell, I found that in the setting box for pi pwm, if you input a number, here are resulting hz readings:
Setting 25=400hz
Setting 50=200hz
Setting 60=166hz
Setting 75=133 hz
Setting 100=100hz
Setting 150=66hz
Setting 200=50hz
This formula is the relationship:
10000/pi pwm box setting=measured hz

As for the pca9685, no matter what I put in the setting box, i get 1500hz

1500Hz is out of the spec for Ldd's (1KHz tops)

Try to force it (reload) to below 1KHz.. seems there is/was a bug about this..

 

[Michael Lane]

Yeah... I don't know anymore.

Those voltage readings look good to me, and LDDs shouldn't require much current on the pwm input. I'm running 4 channels on a PCA9685 without any issue. I think I have a handful of spare LDDs, so I'll try to reproduce this.

 

[oreo54]

Those voltage readings look good to me, and LDDs shouldn't require much current on the pwm input. I'm running 4 channels on a PCA9685 without any issue. I think I have a handful of spare LDDs, so I'll try to reproduce this.

Yea!!!.. ;)

 

[Michael Lane]

I just double checked the data sheet, and it does state frequency should be 100 - 1000Hz, so make sure you are in that range. I believe reef-pi defaults to 1500 for PCA9685.

PWM signal is valid between 2.5 - 6v, that part looks good too.

 

[AbjectMaelstroM]

I just double checked the data sheet, and it does state frequency should be 100 - 1000Hz, so make sure you are in that range. I believe reef-pi defaults to 1500 for PCA9685.

PWM signal is valid between 2.5 - 6v, that part looks good too.

Yeah, I had to go back and delete the original PCA driver and remade it at 1Khz, maybe I should go lower?

 

[AbjectMaelstroM]

Well got that sorted with the help of @brandon clow whom pointed out a very obvious fact.... That the pwm wasn't grounded at the driver board side. I completely missed as there is no dedicated plug for pwm ground only pwm pins. After running the pwm ground to an empty power in V- the flicker is gone, running all 8 channels.

With that behind me, a new issue popped up as the Puck leds don't fully power off at 0 pwm and stay lit at what appears to be 1% or less, brightness.

 

[oreo54]

Weird.. you miss the ground and it usually doesn't dim at all..or light w/ the pull downs out..

 

[Michael Lane]

Well got that sorted with the help of @brandon clow whom pointed out a very obvious fact.... That the pwm wasn't grounded at the driver board side. I completely missed as there is no dedicated plug for pwm ground only pwm pins. After running the pwm ground to an empty power in V- the flicker is gone, running all 8 channels.

With that behind me, a new issue popped up as the Puck leds don't fully power off at 0 pwm and stay lit at what appears to be 1% or less, brightness.

That may be a bug in reef-pi. There has been a recurring bug in the PCA9685 driver that doesn't completely turn off the PWM output. I'm not sure if the fix is in a release yet, but @Ranjib would probably know.

 

[Ranjib]

Well got that sorted with the help of @brandon clow whom pointed out a very obvious fact.... That the pwm wasn't grounded at the driver board side. I completely missed as there is no dedicated plug for pwm ground only pwm pins. After running the pwm ground to an empty power in V- the flicker is gone, running all 8 channels.

With that behind me, a new issue popped up as the Puck leds don't fully power off at 0 pwm and stay lit at what appears to be 1% or less, brightness.

Yes, this is a bug in reef-pi pca9685 driver. I plan to fix it soon as i get some time. Definitely before 3.0 release. https://github.com/reef-pi/reef-pi/issues/794

Meantime, if you can, then use a timer to switch off the light power source after due period, as workaround,

 

[AbjectMaelstroM]

Well got that sorted with the help of @brandon clow whom pointed out a very obvious fact.... That the pwm wasn't grounded at the driver board side. I completely missed as there is no dedicated plug for pwm ground only pwm pins. After running the pwm ground to an empty power in V- the flicker is gone, running all 8 channels.

With that behind me, a new issue popped up as the Puck leds don't fully power off at 0 pwm and stay lit at what appears to be 1% or less, brightness.

Aaand we can disregard the "new issue" as it appears to be a known pwm issue to be fixed in upcoming 3

Weird.. you miss the ground and it usually doesn't dim at all..or light w/ the pull downs out..

Yeah, that's partly why I didn't think about it...indidnt expect it to work at all.

Well now that problems are solved.... On to the meat and potatoes. Do I leave the pucks as is, or replace some of the colors. :cool:

Times like these in wish I had a spectral analyzer.

 

[AbjectMaelstroM]

Think I'm going to kill off the yellow/amber and replace it with mints. Maybe add hyperviolets... 3 per fixture? 4 mints per fixture?

What do you guys think?

 

[Halo_003]

Think I'm going to kill off the yellow/amber and replace it with mints. Maybe add hyperviolets... 3 per fixture? 4 mints per fixture?

What do you guys think?

Not sure how many of each to add but I like the idea of the hyper violets. More UV is the only thing I wish these AcroStar Pros had, but granted I haven’t seen them over the rank yet.. I’ve considered adding a couple of 3up boards with some sub 400nm diodes to my build but haven’t decided so far. Adding mints is a good idea, I liked what they did with the spectrum on Nanobox arrays.

 

[theatrus]

Not sure how many of each to add but I like the idea of the hyper violets. More UV is the only thing I wish these AcroStar Pros had, but granted I haven’t seen them over the rank yet.. I’ve considered adding a couple of 3up boards with some sub 400nm diodes to my build but haven’t decided so far. Adding mints is a good idea, I liked what they did with the spectrum on Nanobox arrays.

More violets are coming with the refresh as I switch to the Luxeon C + SemiLED lineup :)