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

Hi friends ....
i'm planning to use one cheep PWM driver from china for moon lighting. In this i'm really not happy to connect my PWM (5v) from pca9685 to my led Driver (5v pwm)
If the drive fail, high volt from driver will burn the pca9685 or pi . So is it necessary to isolation pwm power between them... if so how to do it ...

3W-5-35V-LED-Driver-700mA-PWM-Dimming-DC-to-DC-Step-down-Constant-Current.jpg

here is the product link

https://www.tanotis.com/products/ta...vMapxB9UUJJax70K0dBTvfMc1Xp-orWoaAgnKEALw_wcB
Hello, welcome to R2R and I'm glad to see you found the Reef-Pi.

I recommend that you use a PCA9685 to generate the pwm signals then scale to the voltage needed using a mosfet as per the guide here https://learn.adafruit.com/reef-pi-lighting-controller/circuit-construction "The power MOSFET based control circuit for the 12V actinic LED strip is mounted on a small Mint Tin size perma proto board. A common N channel logic level power MOSFET is used, with the PCA9685 PWM output connected to the Gate pin (green wire), the Source pin connected to the -Ve end of the LED strip (blue wire) and the Drain pin connected to GND." This will work for most applications and if your moon lighting is not 12v just replace the 12v on the diagram with what you need.
 
Hi friends ....
i'm planning to use one cheep PWM driver from china for moon lighting. In this i'm really not happy to connect my PWM (5v) from pca9685 to my led Driver (5v pwm)
If the drive fail, high volt from driver will burn the pca9685 or pi . So is it necessary to isolation pwm power between them... if so how to do it ...

3W-5-35V-LED-Driver-700mA-PWM-Dimming-DC-to-DC-Step-down-Constant-Current.jpg

here is the product link

https://www.tanotis.com/products/ta...vMapxB9UUJJax70K0dBTvfMc1Xp-orWoaAgnKEALw_wcB
From the initial look, I think this circuit already has those safety nets and you can use it readily, but we need specs (Datasheet) for that chip to be sure. I'll let others who know more chime in..
 
@Ranjib After working this many ways I have finally found a way to implement the parabolic lighting pattern which replicates the sun's constantly changing intensity. As per https://www.advancedaquarist.com/2013/12/lighting and many other studies and the chart posted by @Bigtrout a while back

y = a(x-U)2 + E

Reef-Pi Settings Which I use for example
Min 0 - Q
Max 70 - E
Start 10 - W

Start time 9 - R
End time 21 - T

Middle of day (needs to be calculated) - U

U=((T-R)/2)+R
U=((21-9)/2)+9
U=(12/2)+9
U=6+9
U=15

Now we start to fill out and solve

y = a(x-U)^2 + E
y = a(x-15)^2 + 70

To find a, plug in the values to (x,y) from the known start point (R,W) (9,10):

y = a(x-15)^2 + 70
W = a(R-15)^2 + 70
10 = a(9-15)^2 + 70
10 = a(-6)^2 + 70
10 = 36a + 70
-60 = 36a
a = −1.666666667

The final equation is

y = −1.666666667(x-15)^2 + 70

y is now the intensity %
x is now the time where hours are whole numbers and minutes are a decimal for example 9:30 is 9.5

e36038dad589677678222616a98439ed.png
 
@Ranjib the dernal cycle also has a bug where when I set the minimum to 0 and the start to 10 because 10 is the starting threshold of the mars aqua's working it is not ending at 10% at 21:00 or starting at 10% at 9:00 instead it appears to ignore the starting value and is ending at 0 at 21:00 which shuts off the lights early and too quickly as it should ramp down from 70 to 10 with the last bit being the slowest and instead it blows throught 10% and shut the lights off at 8:25 by going under the 10%

12ffa72121f8d5525f97b395263a43bd.png
 
@Ranjib the dernal cycle also has a bug where when I set the minimum to 0 and the start to 10 because 10 is the starting threshold of the mars aqua's working it is not ending at 10% at 21:00 or starting at 10% at 9:00 instead it appears to ignore the starting value and is ending at 0 at 21:00 which shuts off the lights early and too quickly as it should ramp down from 70 to 10 with the last bit being the slowest and instead it blows throught 10% and shut the lights off at 8:25 by going under the 10%

12ffa72121f8d5525f97b395263a43bd.png
Can test with setting the min 10 and start at 0. I’m planning to remove the start setting
 
@Ranjib After working this many ways I have finally found a way to implement the parabolic lighting pattern which replicates the sun's constantly changing intensity. As per https://www.advancedaquarist.com/2013/12/lighting and many other studies and the chart posted by @Bigtrout a while back

y = a(x-U)2 + E

Reef-Pi Settings Which I use for example
Min 0 - Q
Max 70 - E
Start 10 - W

Start time 9 - R
End time 21 - T

Middle of day (needs to be calculated) - U

U=((T-R)/2)+R
U=((21-9)/2)+9
U=(12/2)+9
U=6+9
U=15

Now we start to fill out and solve

y = a(x-U)^2 + E
y = a(x-15)^2 + 70

To find a, plug in the values to (x,y) from the known start point (R,W) (9,10):

y = a(x-15)^2 + 70
W = a(R-15)^2 + 70
10 = a(9-15)^2 + 70
10 = a(-6)^2 + 70
10 = 36a + 70
-60 = 36a
a = −1.666666667

The final equation is

y = −1.666666667(x-15)^2 + 70

y is now the intensity %
x is now the time where hours are whole numbers and minutes are a decimal for example 9:30 is 9.5

e36038dad589677678222616a98439ed.png
I have recently introduced a sine wave profile as part of the pwm profile work, which gives very similar effect (0 to pi )
 
Can test with setting the min 10 and start at 0. I’m planning to remove the start setting
Seems like that works. Seems as if the settings are confused or maybe I am lol. I assumed min was to keep it on a minimum light at all times regardless of timer and start was how you wanted it to start or something. Idk lol.
 
@Ranjib Just got my ph calibration solutions at 7 and 10. What is the recommendation on how to do it. Should I wash the probe in rodi then put in 7 first or 10 first? How long should it sit there? Do I just wrote down the mv values or do I need to run some commands? Thanks! Excited!
 
Seems like that works. Seems as if the settings are confused or maybe I am lol. I assumed min was to keep it on a minimum light at all times regardless of timer and start was how you wanted it to start or something. Idk lol.
yes. The start setting is confusing and I am planning to remove it. Light UI will go through many changes, including pluggable profiles, ability to customize 1 min to 15 min interval values etc etc..
 
@Ranjib Just got my ph calibration solutions at 7 and 10. What is the recommendation on how to do it. Should I wash the probe in rodi then put in 7 first or 10 first? How long should it sit there? Do I just wrote down the mv values or do I need to run some commands? Thanks! Excited!
temperature is more important. Gentle rinse in normal salt water or ro di water is good but not necessary if you ask me. Whats most important is the calibration done at same temperature as tank and the probe is there for some time so that the readings gets settled (few minutes at least)...
 
@Ranjib Just got my ph calibration solutions at 7 and 10. What is the recommendation on how to do it. Should I wash the probe in rodi then put in 7 first or 10 first? How long should it sit there? Do I just wrote down the mv values or do I need to run some commands? Thanks! Excited!
Yes.. keep it for few minutes, poll the probe at 15s interval and just watch the readings in dashboard or log, note it down.. then run the calibration command
 
When will we see that? I'd love to see that asap!
Don't ask for timelines they imply promises, and we have only one planned release , during thanksgiving :)
all the beta releases will be in between but not any specific cadence, its as and when I get those done..
 
Don't ask for timelines they imply promises, and we have only one planned release , during thanksgiving :)
all the beta releases will be in between but not any specific cadence, its as and when I get those done..
Any way I could buy you a coffee or red bull to get that pushed in the next beta ;)
 
Can someone help me troubleshoot a Temp Sensor Probe DS18b20. It was working fine, I rebooted the pi and it went missing.
Red - GPIO 1, Yellow - GPIO 4, Black - Ground GPIO 6 4.7ohm resistor. I tried resetting the database using
sudo systemctl stop reef-pi.service
sudo rm -f /var/lib/reef-pi/reef-pi.db
sudo systemctl start reef-pi.service
with no luck
 
Can someone help me troubleshoot a Temp Sensor Probe DS18b20. It was working fine, I rebooted the pi and it went missing.
Red - GPIO 1, Yellow - GPIO 4, Black - Ground GPIO 6 4.7ohm resistor. I tried resetting the database using
sudo systemctl stop reef-pi.service
sudo rm -f /var/lib/reef-pi/reef-pi.db
sudo systemctl start reef-pi.service
with no luck
Did you try to delete the sensor and re add it
 

ARE YOU READY TO CONFESS TO CRAZIEST, DUMBEST, FUNNIEST THING YOU’VE EVER DONE IN REEFING?

  • Yeah, I'll confess! (Share your story in the comments!)

    Votes: 14 58.3%
  • Nah, I'll keep mine a secret...(Don't be like that, share with the class!)

    Votes: 10 41.7%
Back
Top
Home
Post thread…
Market
What's new