My reef-pi build freshwater style!

[Ranjib]

@Ranjib What other things would you recommend besides RTC?

UPS. Note, i dont use any of those . My power and network is pretty stable (touch wood), and I also use extensive monitoring (web operations style), with everything pulled in prometheus/grafana and alert based on it. Something I should probably write up somewhere... :sigh:

 

[Bigtrout]

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.

Sounds like the same one i dealt with...it wont take 30 days...he told me that as well, but they arrived in 16. He will even put a trackin number in ebay for u

 

[Bigtrout]

There are others..
https://www.ebay.com/itm/20x-400W-DC-5-36V-Large-Power-Mosfet-MOS-FET-Trigger-Switch-Driver-Module/264284877024?_trkparms=ispr=1&hash=item3d889b30e0:g:LJYAAOSwrANctHOH&enc=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&checksum=2642848770240636c79eea1a4b71b94ba4f84b5f3c01

Those wont work for our beamswork lights
..they are n channel fets

 

[oreo54]

Those wont work for our beamswork lights
..they are n channel fets

NPN MOSFETS are perfect for Beamsworks LED's as long as you aren't splitting channels.. then yes PNP ones are needed..
TC-420 runs 5 NPN (5V PWM gate) MOSFETS..
Needed to be reversed for splitting Finnex planted plus into 3 channels..

 

[Bigtrout]

We are both splitting the channels, so PNP it is...I like my moonlights. Besides that reef pi with a pca9685 has the same functionality as a tc420, and can control 16 channels

 

[Michael Lane]

@Ranjib What other things would you recommend besides RTC?

I also recommend setting up watchdog timer. My reef-pi locked up (with lights on). Good thing it was lights instead of doser... For me, root cause was SD card error. Maybe RTC would have prevented this, but it's a pretty old card by now.

 

[oreo54]

I also recommend setting up watchdog timer. My reef-pi locked up (with lights on). Good thing it was lights instead of doser... For me, root cause was SD card error. Maybe RTC would have prevented this, but it's a pretty old card by now.

SD cards wear out due to many log writes..

it's a very weak point and common..
https://hackaday.com/2019/04/08/give-your-raspberry-pi-sd-card-a-break-log-to-ram/

The fragility of SD cards is the weak link in the Raspberry Pi ecosystem. Most of us seem to have at least one Pi tucked away somewhere, running a Magic Mirror, driving security cameras, or even taking care of a media library. But chances are, that Pi is writing lots and lots of log files. Logging is good — it helps when tracking down issues — but uncontrolled logging can lead to problems down the road with the Pi’s SD card.

From a personal trusted source:

I was noticing how many folks were burning out SD cards doing these big expensive builds (with swap files) instead of using a USB drive for the kind for stuff that thrashes the SD card. Faster too.

My dev board has a pocket USB drive hooked up to it for that reason.

 

[Bigtrout]

I also recommend setting up watchdog timer. My reef-pi locked up (with lights on). Good thing it was lights instead of doser... For me, root cause was SD card error. Maybe RTC would have prevented this, but it's a pretty old card by now.

This is something I need to do, just in case.

 

[Bigtrout]

I bought a Milwaukee 911/2 ph probe and some calibration solution packets, it was all supposed to come today, hasnt showed up...UPS lost the dang package...uggghhh...time to fight with UPS and Amazon

 

[Bigtrout]

@Michael Lane or @theatrus
How hard is designing a pcb?

Im ok with the fet modules I just got but being the perfectionist that I am, I can make a better module to be able to use 1500hz from the pca9685 at full resoultion from 0 to 100 percent. Yes I could do totem pole or push pull transistors to drive a p channel fet but thats more complicated than I need and needs 3 bjts and a bunch of resistors to do correctly.

My thoughts were using a tc426 which is a dual channel inverting gate 1.5amp driver to drive 2 p channel fets. Its 8 pin dip, only needs a .1uf and 4.7uf capacitor on V+ to smooth the chip power in, and can use 3.3V logic directly on inputs to drive 2 seperate fets at up to a 18v power supply. So I could do all thru hole components. Id only need 1 tc426, 2 good p channel fets, a .1 and 4.7uf capacitor and 2 10 ohm resistors and a few odd connectors to make a dual channel pwm mosfet module. It could easily use n channel fets instead. The chip datasheet does say to have a large ground plane to tie all the grounds together.

Any input would be welcome.

I could easily do 2 of these on stripboard laying in wire for the higher current section but thought this could be a nice add to the project to easily tie simpler led strips to pwm.

 

[Michael Lane]

Designing a pcb has its share of challenges, but I'm sure you'd be able to pick it up pretty quickly. It sound like you know how you want the circuit to work, and that's half the challenge.

I started with Eagle, but switched to Kicad since it is open source and to get around the size limit. I find the physical layout to be the most difficult task, but I think it does get easier with practice. If you don't plan to etch the board yourself, then through hole is fine. Lately, I like to use JLCPCB for manufacturing the board.

Keep us posted on your progress. I'd be happy to see your designs and provide whatever feedback I can. I'd also look forward to seeing advice from theatrus, his work looks really good, so I'm sure I could learn a lot from it too.

 

[Bigtrout]

Im looking at thru hole with easy parts and would like to add the design to the pi github so others could easily roll their own. With the right fets and design, these could easily do 5 amps per channel thru the fets with little heat buildup.

 

[Ranjib]

Im looking at thru hole with easy parts and would like to add the design to the pi github so others could easily roll their own. With the right fets and design, these could easily do 5 amps per channel thru the fets with little heat buildup.

totally looking forward to this

 

[Bigtrout]

I bought a Milwaukee 911/2 ph probe and some calibration solution packets, it was all supposed to come today, hasnt showed up...UPS lost the dang package...uggghhh...time to fight with UPS and Amazon

I ended up having to go on an unplanned trip out of town and had my wife tangle with UPS and Amazon.
Ph probe arrives Tuesday!!!

 

[Mikeneedsahobby]

I just got my 2nd probe and ph board for the planted tank. Install today, hopefully.

 

[AquaRaider44]

I just got my 2nd probe and ph board for the planted tank. Install today, hopefully.

Sweet post an update with some pics of your setup and tanks. I used to love fresh water.

 

[Mikeneedsahobby]

Sweet post an update with some pics of your setup and tanks. I used to love fresh water.

Thanks, It is up and running!

Here is my build thread.
electrical idiot builds a controller - a reef pi build

 

[Bigtrout]

Woohoo, my ph probe finally got here!
Boohoo, my calibration solution packets a day or two behind.

I went with the Milwaukee MA911B/2.
So far plugged in to the ph board sitting in its shipping solution, its giving me a pretty steady raw reading of around 7350.

I suppose I could megadose some water with baking soda to get an 8.2 and add some to water to get a definite green(7) with my ph test kit, but ill probably just wait and calibrate it correctly.

Note to self, buy a jug of distilled water to mix my calibration solutions when the packets get here.

 

[AquaRaider44]

Woohoo, my ph probe finally got here!
Boohoo, my calibration solution packets a day or two behind.

I went with the Milwaukee MA911B/2.
So far plugged in to the ph board sitting in its shipping solution, its giving me a pretty steady raw reading of around 7350.

I suppose I could megadose some water with baking soda to get an 8.2 and add some to water to get a definite green(7) with my ph test kit, but ill probably just wait and calibrate it correctly.

Note to self, buy a jug of distilled water to mix my calibration solutions when the packets get here.

Just wait for the proper solution it's not worth it being off.

 

[Bigtrout]

Im old school, drawing up my mosfet driver circuit on paper...lol
Will have to post it up later.

Ill probably do my pcb layout on graph paper before I start learning pcb making software.