My reef-pi build freshwater style!

[Mikeneedsahobby]

[QUOTE="Bigtrout, post: 6065082, member: 113707”]

Perhaps even dabble in....
SALTWATER!!!!![/QUOTE]

Make sure you where a tux at least 3 times per week if you want corals to survive.

 

[Ranjib]

@Bigtrout how's the controller doing? Any hiccups?

 

[Bigtrout]

No hiccups at all...which says alot. I am in rural NW PA with frequent power and /or internet outtages. And the pi runs flawlessly...i do wonder if my addition of the real time clock helps in this regard, so raspbian doesnt corrupt.

Going to order my ph probe and move to the 3.0 pre release, I already have the ph board from JT mounted and on the i2c bus with an address.its been there since I got it in Feb. Just have to plug in the probe when it arrives.

 

[Bigtrout]

A bit off topic here, but I have a chance at a 60 gallon framed, reef ready cube(tank only with built in overflow) for $100.

Should I go for it? Not ready to set up until fall but i think its a heck of a deal. With my 75 gallon, I dont have alot of room and another long tank is out of the question. But a 24x24 footprint could work...

I looked at the tank, its a marineland and the overflow setup is very dumb, and not easily fixed so I decided to pass on it.

Its time to get my stuff together to install my 40 breeder sump under my 75 gallon so I can ditch the 3 big sun sun canisters.

 

[Ranjib]

No hiccups at all...which says alot. I am in rural NW PA with frequent power and /or internet outtages. And the pi runs flawlessly...i do wonder if my addition of the real time clock helps in this regard, so raspbian doesnt corrupt.

Going to order my ph probe and move to the 3.0 pre release, I already have the ph board from JT mounted and on the i2c bus with an address.its been there since I got it in Feb. Just have to plug in the probe when it arrives.

RTC clock is invaluable if you ask me. I am planning to make a list of recommended things and RTC is one of them. Without it, every restart risks serious time difference induced anomalies in controller behavior.

 

[crusso1993]

I looked at the tank, its a marineland and the overflow setup is very dumb, and not easily fixed so I decided to pass on it.

Its time to get my stuff together to install my 40 breeder sump under my 75 gallon so I can ditch the 3 big sun sun canisters.

Nice! What media will you be using for biological?

 

[Bigtrout]

Water will flow thru:
3 inch thick 10 ppi poret foam
3 inch thick 20ppi poret foam
A ton of pot scrubbies
Ceramic media

My middle section is empty but has enough space for some k1 media if needed

Then it has to flow thru another big block of 10ppi foam to hit my return chamber.

 

[Bigtrout]

Still tinkering with my pwm on my lights, I should really just build my own boards to interface, but dont have the time to do it.

My lights run common ground so basically pwm from the pca9685 needs to turn a p channel mosfet on amd off to run my lights.

I bought these modules, and although they work, and have a really good p channel mosfet in them, the way they did the circuit, they really slowed down the turn off of the mosfet and the optocoupler, by using too high of a pullup resistor. The specs when I bought them said they work at 0 to 1500 hz. In reality they were only usable to about 200 hz, and with the long mosfet turn off times, I didnt get very good resolution. 1 percent duty cycle at 120hz, still had the lights at 20 percent brightness. So these modules were built well, but not engineered very well. They were DfRobot modules.

So leave it to ebay, I found some different modules that use p channel mosfets and are optoisolated. The circuiting is much better allowing for faster mosfet turn off times and more usable range for pwm. These modules are usable with good range to 1000hz. They have a decent p channel mosfet, with a little more on state resistance, but at 4 amps max per channel, they are quite usable. These modules look like this

So I installed these and now I can dim to a real 1 percent at 500hz which is alot easier on the eyes than 100-200 hz. The fish will appreciate the gentler sunrise and sunsets as well!

I should really build my own circuit with either 2 transistors in a push pull configuration, or a mosfet driver IC. That would let me speed up the pwm more but since the PCA9685 only goes to 1500hz, its not worth the bother. The modules I used are usable to 1000hz and cost 7 dollars for 4 of them shipped from China

 

[Ranjib]

Still tinkering with my pwm on my lights, I should really just build my own boards to interface, but dont have the time to do it.

My lights run common ground so basically pwm from the pca9685 needs to turn a p channel mosfet on amd off to run my lights.

I bought these modules, and although they work, and have a really good p channel mosfet in them, the way they did the circuit, they really slowed down the turn off of the mosfet and the octocoupler, by using too high of a pullup resistor. The specs when I bought them said they work at 0 to 1500 hz. In reality they were only usable to about 200 hz, and with the long mosfet turn off times, I didnt get very good resolution. 1 percent duty cycle at 120hz, still had the lights at 20 percent brightness. So these modules were built well, but not engineered very well. They were DfRobot modules.

So leave it to ebay, I found some different modules that use p channel mosfets and are optoisolated. The circuiting is much better allowing for faster mosfet turn off times and more usable range for pwm. These modules are usable with good range to 1000hz. They have a decent p channel mosfet, with a little more on state resistance, but at 4 amps max per channel, they are quite usable. These modules look like this

So I installed these and now I can dim to a real 1 percent at 500hz which is alot easier on the eyes than 100-200 hz. The fish will appreciate the gentler sunrise and sunsets as well!

I should really build my own circuit with either 2 transistors in a push pull configuration, or a mosfet driver IC. That would let me speed up the pwm more but since the PCA9685 only goes to 1500hz, its not worth the bother. The modules I used are usable to 1000hz and cost 7 dollars for 4 of them shipped from China

I am curious why you can not use standard N channel mosfets or tip 120 style transistors. You have to configure them in reverse mode in reef-pi. You should be able to share the GND. We do similar thing for kessil.

 

[Bigtrout]

I am curious why you can not use standard N channel mosfets or tip 120 style transistors. You have to configure them in reverse mode in reef-pi. You should be able to share the GND. We do similar thing for kessil.

A transistor like a TIP120 could work because its not voltage controlled, it is current controlled, but going thru a transistor junction, you lose .7 to 1 volts, and with a darlington like the tip120 you lose 2 or more volts, therefore you lose some brightness. Good mosfets only lose a fraction of this because of their typical good On state resistance. Going thru a good mosfet with 4 amps of current, I only lose .1 to .3 volts.

N channel mosfets are best at low side switching. You place them between the load and ground. Then you need a positive voltage on the gate to turn them on or off.

Because the grounds in my led light are all on a single plane on the pcb ,I can not easily get the mosfet between the load and ground, so i have to use a p channel.

P channel mosfets are best used as high side switches, placed between voltage source and your load. The gate needs a negative voltage in respect to the source(V+) to turn on.

Because my lights are 15 volts, with a p channel fet 14 to 15 volts turns it fully off, 10 to 11 volts turns it fully on. Since the pca9685 on the @Michael Lane hat has only 0-3.3v as its pwm output i need some type of level shifter between the pca and the mosfet. You can use a npn transistor or like my china boards which use an optocoupler.

 

[Bigtrout]

In other tank news, RIP to my Bristlenose pleco male.

He survived a major tank move, fathered several small plecos which are currently in my tank, and I had him 7 years. Heres a pic of him on the right side laying by the driftwood.

 

[crusso1993]

In other tank news, RIP to my Bristlenose pleco male.

He survived a major tank move, fathered several small plecos which are currently in my tank, and I had him 7 years. Heres a pic of him on the right side laying by the driftwood.

Sorry for your loss. Sounds like he had a good life!

 

[Bigtrout]

Sorry for your loss. Sounds like he had a good life!

Checked all tank parameters...everything looking good, 0 ammonia, 0 nitrites, nitrates 12ppm, ph 6.7, kh 4, other fish all looking happy and active, so im attributing it to old age, he was fairly good sized when I got him.

He was my favorite fish, but my wife thought he was butt ugly, lol!

 

[Ranjib]

In other tank news, RIP to my Bristlenose pleco male.

He survived a major tank move, fathered several small plecos which are currently in my tank, and I had him 7 years. Heres a pic of him on the right side laying by the driftwood.

Sorry to hear that. Tank looks gorgeous though

 

[Mikeneedsahobby]

He was my favorite fish, but my wife thought he was butt ugly, lol!

The girl pleco liked him so he must have had personality or told good jokes.

Sorry for your loss.

 

[Mikeneedsahobby]

Still tinkering with my pwm on my lights, I should really just build my own boards to interface, but dont have the time to do it.

My lights run common ground so basically pwm from the pca9685 needs to turn a p channel mosfet on amd off to run my lights.

I bought these modules, and although they work, and have a really good p channel mosfet in them, the way they did the circuit, they really slowed down the turn off of the mosfet and the optocoupler, by using too high of a pullup resistor. The specs when I bought them said they work at 0 to 1500 hz. In reality they were only usable to about 200 hz, and with the long mosfet turn off times, I didnt get very good resolution. 1 percent duty cycle at 120hz, still had the lights at 20 percent brightness. So these modules were built well, but not engineered very well. They were DfRobot modules.

So leave it to ebay, I found some different modules that use p channel mosfets and are optoisolated. The circuiting is much better allowing for faster mosfet turn off times and more usable range for pwm. These modules are usable with good range to 1000hz. They have a decent p channel mosfet, with a little more on state resistance, but at 4 amps max per channel, they are quite usable. These modules look like this

So I installed these and now I can dim to a real 1 percent at 500hz which is alot easier on the eyes than 100-200 hz. The fish will appreciate the gentler sunrise and sunsets as well!

I should really build my own circuit with either 2 transistors in a push pull configuration, or a mosfet driver IC. That would let me speed up the pwm more but since the PCA9685 only goes to 1500hz, its not worth the bother. The modules I used are usable to 1000hz and cost 7 dollars for 4 of them shipped from China

I think I found the mosfet on eBay. It is listed as an e-switch mosfet. It is the exact picture you showed though. It is 1.76 per mosfet. Is this the right one? I am currently running my pca9685 at 100hz.

 

[Bigtrout]

Yes, basically if it looks like this and was called an eswitch. Mine were ebay and 4 of them cost around 7 dollars shipped so the 1.76 sounds about right.
This module gives me better range of dimming at the low end, PLUS lets me up the frequency to a much better on the eyes 500hz

 

[AquaRaider44]

RTC clock is invaluable if you ask me. I am planning to make a list of recommended things and RTC is one of them. Without it, every restart risks serious time difference induced anomalies in controller behavior.

@Ranjib What other things would you recommend besides RTC?

 

[Mikeneedsahobby]

Yes, basically if it looks like this and was called an eswitch. Mine were ebay and 4 of them cost around 7 dollars shipped so the 1.76 sounds about right.
This module gives me better range of dimming at the low end, PLUS lets me up the frequency to a much better on the eyes 500hz

I have 2 on order. It will take 30 days or more to arrive. I received a nice email from the seller. The English was broken a bit but it’s far more than I would expect for a $7 purchase. You can tell the guy cares about his business. Honestly I wouldn’t have expected any customer service on this purchase.

 

[oreo54]

There are others..
https://www.ebay.com/itm/20x-400W-D...=2642848770240636c79eea1a4b71b94ba4f84b5f3c01

Description:

- High power MOS field effect tube trigger switch driver module PWM regulating electronic switch panel.
- Adopts imported large power dual-mos transistor parallel active output, lower resistance, higher current and strong power.
- Perfect support PWM signal: the PWM controller can access PWM signal, which can perfectly supported the frequency of 0-20khz.
- This motor control module can tolerate wide input Voltage (DC 5-36v) it can be applied in various high power equipments,
- Applications: motor,lamp bulb,LED lamp strip, micro water pump etc.

Specification:

- Operating VoltageC 5V-36V
- Trigger Signal Source: digital high/low level (DC 3.3-20V),can connect with MCU IO port, PLC interface, DC power etc; can connect with PWM signal; support signal frequency 0--20KHz.
- Output Power: DC 5v-36v, room temperature sustained current 15A, power 400W! Auxiliary cooling conditions, the maximum current can be up to 30A.
- Operating Temperature: -40~85 Celsius