reef-pi :: An opensource reef tank controller based on Raspberry Pi.

[Bigtrout]

So I have been successfully using reef pi since the start of November. Mainly the temp and Lighting PWM function. I ran into an issue today that has me wondering about the limitation of the PCA9685 board. I run 3 boards, one for each light fixture. They are equipped with a ldd mean well 1000mA (blues), 1000mA(Whites), and a 700mA(UV/Violets). Each board has jumpers to enable the PWM function of the ldd driver. I use a total of 9 pins from the PCA board, all works great until I go 80% on my blues, 60% on my whites, and 80 on my UV/Violets. The entire system dims to almost in half on every pwm output (visually, since the system status in terminal shows whats set in the UI of reef pi). I can pull all 9 jumpers and 100% on every channel without issue. I am only using the PWM portion of thePCA9685. I did validate that I can run a 80/60/80 on two lights and the last one at a 80/10/80 without loss but anything higher on the last one starts to dim the rest of the system.

Any ideas? I have also played with the frequency with stop and start command in the terminal after to make sure its getting a fresh start after hitting update int he UI.

How are you powering your PCA board?

 

[brandon clow]

How are you powering your PCA board?

Right from the pi...that's what I have been wondering if I need to get a separate 5v power supply to the pca board.

 

[Bigtrout]

Right from the pi...that's what I have been wondering if I need to get a separate 5v power supply to the pca board.

And you are running just a pwm signal from the PCA, one to each meanwell LDD? Do you have a pic of your hook ups

 

[stefanm]

Right from the pi...that's what I have been wondering if I need to get a separate 5v power supply to the pca board.

If it helps, I run a clone of storm x for my lights, based on Arduino, the PCA is powered directly from the Arduino, the pwm output goes to the meanwell drivers, the ground and + are not used on the output, should be the same on the pi, you do need to put are wire from the output side of the pwm ground and common it to the PSU of the lights.

And don't forget the pull down on the ldd's from the pwm.

 

[Bigtrout]

If it helps, I run a clone of storm x for my lights, based on Arduino, the PCA is powered directly from the Arduino, the pwm output goes to the meanwell drivers, the ground and + are not used on the output, should be the same on the pi, you do need to put are wire from the output side of the pwm ground and common it to the PSU of the lights.

And don't forget the pull down on the ldd's from the pwm.

Grounding was going to be my next question, kinda why I wanted to see his hookups

 

[brandon clow]

I am only using the PCA for the PWM side of things. All of the other wires are running from pi to PCA. I should be running the PCA input ground to the Mean Well PSU as well?

 

[brandon clow]

I see the picture did not attach

 

[brandon clow]

Well I added a ground into the pca circuit to my meanwell psu and that really made a big difference!

 

[Bigtrout]

I am only using the PCA for the PWM side of things. All of the other wires are running from pi to PCA. I should be running the PCA input ground to the Mean Well PSU as well?

No you need a wire from the PCA pwm output ground to the light PSU ground.
What you are doing is making sure both grounds are common to each other so voltages have a common reference point. The meanwell driver takes +3.3v on the pwm pin to work. + 3.3v above its GND. When you send a seperate signal to the LDD that signal is referenced to what? Its not referenced to anything. By connecting the PCA output GND to the GND of the light PSU that +3.3 volts is now referenced to the LDD gnd.
Without a common reference point the PWM was a "floating" signal and may have been your problem.

 

[brandon clow]

No you need a wire from the PCA pwm output ground to the light PSU ground.
What you are doing is making sure both grounds are common to each other so voltages have a common reference point. The meanwell driver takes +3.3v on the pwm pin to work. + 3.3v above its GND. When you send a seperate signal to the LDD that signal is referenced to what? Its not referenced to anything. By connecting the PCA output GND to the GND of the light PSU that +3.3 volts is now referenced to the LDD gnd.
Without a common reference point the PWM was a "floating" signal and may have been your problem.

I did this and it works great, no more issue and it seems the general output is now increased by quite a bit per my par meter/visually! Thanks!

 

[Bigtrout]

No problem, glad I could help. This is why reef pi is awesome, great software, and good support if you run into trouble.

 

[Bigtrout]

Im good on the electronic end of things with reef pi, but I do have a software question. Can reef pi be setup to interface to IFFT or home assistant or the like?
Would be awesome to tell Alexa, im going to feed my fish, and have a macro started to shut off my filters for a time...etc

 

[b4tn]

Im good on the electronic end of things with reef pi, but I do have a software question. Can reef pi be setup to interface to IFFT or home assistant or the like?
Would be awesome to tell Alexa, im going to feed my fish, and have a macro started to shut off my filters for a time...etc

Now that would be cool!

 

[tatties]

could someone with no coding experience do this reefpi? sounds interesting.

 

[b4tn]

I’m having an issue with macros. Specifically turning off times. I need to switch off my power heads as part of a feeding routine. Since all my power heads are on timers if I select to turn it off it just comes back on after 30 seconds or so. I built a macro to turn off all my power head timers then turn them back on after 5 seconds to test and when I hit run nothing happens. Does this function not work yet?

 

[Ranjib]

could someone with no coding experience do this reefpi? sounds interesting.

Yes. You need some familiarity with computer, but no programming required

 

[Ranjib]

Im good on the electronic end of things with reef pi, but I do have a software question. Can reef pi be setup to interface to IFFT or home assistant or the like?
Would be awesome to tell Alexa, im going to feed my fish, and have a macro started to shut off my filters for a time...etc

There’s api , so you can do pretty much anything you want. I know there are reef-pi google home assistant integration out there

 

[rushbattle]

Yes. You need some familiarity with computer, but no programming required

I wouldn’t know where to even begin coding something very simple, but I use reef-pi pretty easily.

 

[Ranjib]

I’m having an issue with macros. Specifically turning off times. I need to switch off my power heads as part of a feeding routine. Since all my power heads are on timers if I select to turn it off it just comes back on after 30 seconds or so. I built a macro to turn off all my power head timers then turn them back on after 5 seconds to test and when I hit run nothing happens. Does this function not work yet?

I think it’s a bug. Let me take a look

 

[dmolavi]

There’s api , so you can do pretty much anything you want. I know there are reef-pi google home assistant integration out there

There is? Where? I use Google Home and it would be cool to have this (maybe...assuming my kids don't get carried away and shut everything off with it).