Reef-PI build thread, go big or go home

[Tristanzs]

So first I'd like to state that I have some electronics experience but have never designed anything beyond a basic circuit before. My plan is to run a primary controller box with built in power supply and 8 controllable outlets. This will include an ATO function with 2 float valves, 2 temperature sensors. The float valves and temp sensors will plug into smaller junction boxes I am going to create so that I can better manage space within the primary control box and allow for quick change should one fail. Essentially I'm going to build the circuit within the primary and then use aviation connectors to run wiring to the junction boxes which will house any application specific boards and mini XLR ports for the individual sensors. I've created a shopping list of parts on amazon and would love any input from people who have experience in this to look over my part selections and perhaps make recommendations to improve on the build.

Here is a link to the parts list http://a.co/1rxciSk

Also I created a diagram of what I envision the setup looking like once complete, it's just a rough idea of how the junction boxes will be setup in relation to the primary control box.

 

[Diamond1]

It Starts! Welcome to the club.

 

[Tristanzs]

Ha not quite yet I'm giving it a few days so people can review my parts list at their leisure and maybe find any flaws in my plan or items I missed.

 

[Ryan115]

1) I am not quite sure on the reasoning for the secondary boxes. There really isn't much to the circuitry for the float switches and the temp sensors (mostly just a few resistors), and the box that you have should be more than large enough. Are you planning to have the outlets contained within that box?

2) The temp probes that you have are one of the things that I would question. That type in general has had very mixed results (across the plethora of different brands). I have had one that rusted completely through within a few months while @Ranjib has had some that have been going for a few years.
The two better recommended replacements would be either the Drok sensors or the epoxy coated ones from Sparkfun (found on Amazon too).

3) If you would like some dummy proofing, you could get some 3-pin mini xlrs to differentiate your sensor ports.

4) Will you be running anything else off of the 5V supply other than the pi? Relays?

 

[Diamond1]

I think your list looks good.
I also agree with @Ryan115 about the temp probes the cheap knock offs are kind of a crap shoot quality wise.
By the way I love the Z-car in you're avatar. I am a big fan of them I have owned one of every model from a 240 through the first generation 300zx.

 

[Tristanzs]

Thanks guys. Mostly the reasoning is to keep everything looking clean and out of the way. I will be adding the outlets to the outside of the primary box. Thanks Diamond it's my toy, I love it to death and decided she needed new shoes for Christmas lol.

 

[Ryan115]

One more comment on your list. I would get a resistor assortment rather than that many of a single value. Or at least get some 1k, 4.7k and 10k.
Between those and the 470 you will be able to handle most situations.

 

[Tristanzs]

Thanks Ryan, I just wanted to make sure I had the kinds I needed so I picked the ones on my list. If anyone has one that they know would be good for me I'd really appreciate it. I'll be updating the list to reflect changes tomorrow.

 

[Tristanzs]

4) Will you be running anything else off of the 5V supply other than the pi? Relays?

I have no idea what else I can run off the power supply really. I mean if I can I'd run as much off it as possible to reduce the need for outlet use. The enclosures I have listed in the amazon link are just placeholders for custom ones I am having a friend 3d print. The primary box will actually be 12x12x6 to give me plenty of depth for the outlets and housing the power supply. To be honest everything is very fluid at the moment, I'm willing to change just about anything if it will improve my build.

 

[Tristanzs]

Does this look like an accurate representation of the way I need to wire my float switches?

 

[Tristanzs]

The way I understand it the PI monitors the switch for on off and then triggers the appropriate port on the power strip to on. I was thinking of simply running the power for my pump through the power supply internally and having a DC jack coming out of my breakout box to plug in the pump. I'm not sure how to replicate the functionality you guys created with this setup. I was thinking it would look something like this, however; I think that bypasses the PI and thus I would be unable to monitor it.

 

[Andrewalex11]

That seems like a nice simple design but personally I would use some solid logic gates to give each float switch their own port to plug into.

 

[Tristanzs]

OK so if I'm understanding your schematic I would solder in the 1k resistors and the logic gate to a PCB and then run to the switches. Then the Pi would turn on power to the pump which would need to be plugged into the power strip at that point correct? Is it possible to power the pump via the power supply I'm building into the system and still have the PI control it's on off?

 

[Ranjib]

Looking forward. The improvements shared above (temperature sensor, single housing, xlr connectors) are sound. I am planning to update the official BOM with these. This should be straight forward.

 

[Ranjib]

That seems like a nice simple design but personally I would use some solid logic gates to give each float switch their own port to plug into.

I am curious why this schematic is better.

 

[Ranjib]

You want to build the power controller from scratch ? theres ADJ SRP8 power strip that will work readily with reef-pi. If you are using scratch power controller, then go for 5v relays, and build a 5V controller. Temperature, ATO , power all can be done in 5V. That way you wont need lm2596 boards. I went with those in the adafruit guides due to the powerstrip.

 

[Bigtrout]

I am curious why this schematic is better.

Wiring 2 switches in series and then to the pi IS a hardwired AND gate! No logic chip needed.

S1 AND S2 both need to be closed to run the light in this example

 

[Ryan115]

@Tristanzs What was your intent for the double float switches?
1) Double switches in sump for redundancy
2) 1 switch in sump, 1 switch in tank/overflow
3) 1 switch in sump, 1 switch in ATO reservoir
4) other configuration

Depending on your intent will change the wiring schematic for it. Also, you can run them independently into separate GPIO ports for more flexibility.

 

[Tristanzs]

I was going to run double float in sump for redundancy. @Ranjib So I won't need the LM2596 boards to control the outlets if I'm using https://smile.amazon.com/dp/B07DNB2...olid=104TCAUWAHXC0&psc=0&ref_=lv_ov_lig_dp_it ?

 

[Tristanzs]

@Bigtrout I was looking at your build thread and your power supply setup is exactly what I'm wanting to do. I have a couple of questions though and was hoping you could explain it to me.
1) When you run the Black White Red and Brown leads off the power supply to the hat on your PI is that what is powering the PI?
2) I see a Yellow and Grey set of leads going from your power supply to the Relay module, are these used to power the relay itself?
3) It appears they power supplies are ran in series, with a positive, negative, and ground ran from your power distribution area to run them? Is this essentially a passthrough from the source that is feeding the outlets?
4) How are you mounting the power supplies to the din rail?

I really appreciate all of the input I've been receiving and all of the great references that allow me to even approach this project with confidence. I've had very little electrical training and never built a circuit before, thankfully I've got soldering experience from RC cars and other projects.