Reef Pi, on a wish and a prayer!

[Ranjib]

Hi Ranjib just noticed your post,
as an addendum to what I've said to Michael I've Just taken a quick look at these power strips on google it may well be the way to go they aren't that expensive either

This is our old guide for building power controller from scratch https://reef-pi.github.io/build-guides/power/
The screenshots are outdated , but the theory/concepts should be still useful

 

[Michael Lane]

Can you provide a link to the relay board you are planning to use?

I think this can be accomplished with a bit of patience and dedication. The guides are helpful and the community is fantastic. I think my boards are very convenient, but they still take some DIY elbow grease.

 

[PaulJ2303]

CHeers guy's

Here is a link to the relay board Ive ordered from amazon:
Aas you can see it's a 12v board but having just looked at Ranjb's scratch build guide i must say i'm quite drawn to the simlicity of driving the relays directly from the gpio's and i suspect that might be the way to incorporate the dosing circuitry onto my pi ?
if so I'm happy to send it back (god bless Amazon) and get a 5v version for example:
what do you guy's think ?

 

[Michael Lane]

Running a relay board directly from the gpio usually works, but could technically have problems. The rpi used 3.3v on the gpio pins. That's usually enough to trigger 5v relay boards, but it's not guaranteed since it is a lower than expected signal. It's also possible that turning all relays on at the same time could require more power than the rpi can provide over gpio.

I'd say the 12v relay board is fine, and will work well with a ULN2803. Connect it 12v to the ULN2803 and relay board. All grounds get connected. 8 gpio go the ULN2803, and then on the relay board.

 

[PaulJ2303]

Ok cheers Michael will do.

BTW thanks for the tip about the 'Jebao dp3s' Ive put one on order

 

[PaulJ2303]

ok so I've made some progress over the last week.
here is a pic of my Pi I've almost completed the power controller, thanks for the advice @Michael Lane:

One issue i have is how to connect the AC outlets to the relays as the wiring diagram on the relay is'nt very descriptive:

 

[PaulJ2303]

So before i finish the power controller part of this build I'm going to branch off a little and try to attach this beast to it:

I am hoping for some help with this stage as i want to try and control all three dosing pumps using the same pi as i'm using for the rest of it.
please pile in with any advice

 

[AbjectMaelstroM]

ok so I've made some progress over the last week.
here is a pic of my Pi I've almost completed the power controller, thanks for the advice @Michael Lane:

One issue i have is how to connect the AC outlets to the relays as the wiring diagram on the relay is'nt very descriptive:

This covers the process of wiring the relays fairly well. Chime in if you have any issues.

 

[Ranjib]

So before i finish the power controller part of this build I'm going to branch off a little and try to attach this beast to it:

I am hoping for some help with this stage as i want to try and control all three dosing pumps using the same pi as i'm using for the rest of it.
please pile in with any advice

pi itself has two pwm controls and you should be able to control at least two of those pumps using them

 

[PaulJ2303]

pi itself has two pwm controls and you should be able to control at least two of those pumps using them

Thanks Ranjib, is there a way to control all three?

 

[PaulJ2303]

This covers the process of wiring the relays fairly well. Chime in if you have any issues.

Thanks very much for that, although here in the UK I'll have to find different plugs I understood how you wired it all up.

Cheers.

 

[AbjectMaelstroM]

Thanks very much for that, although here in the UK I'll have to find different plugs I understood how you wired it all up.

Cheers.

Glad you got it sorted. Though I can't take credit for the video as it's not mine; just something I came across when I first started messing with Reef Pi.

 

[Michael Lane]

You'll probably need to get a pca9685 board to get more pwm channels.

Here's my post modding the doser, but it doesn't have instructions. I helped Aquaraider do the same in his build thread. Take a look at those instructions.

 

[PaulJ2303]

Cheers Michael

 

[PaulJ2303]

Here's my post modding the doser

Unfortunately the link to this post doesn't work for me could you plz post it again.

in the mean time i'll be over here learning about pwm, pca9685 and other arcane acronym's
nice

 

[Michael Lane]

The link to AquaRaider's thread seems to work. That's the good one anyway.
I can pull the details over tonight.

 

[PaulJ2303]

Thanks Michael,
I know you guys have carried a few people through this process now and you should know it's appreciated

 

[PaulJ2303]

I'm having trouble getting the Jebao dp3s dosing pumps to work. i wonder if anyone could point me in the right direction
ive got as far as this:

my board is wired exactly like this.
is there anything else i need to do to get it to work.
i assumed that the pumps would be controlled using the SCL / SDA pins on the PCA9685 but on @AquaRaider44 build thread there is talk of wiring some GPIO pins up but i'm not sure where to wire them up ?

 

[PaulJ2303]

here are a couple of pics of the pca9685 board and it's connections



as you can see the uln2803 is on the board underneath and the outputs to the dosers are connected directly to that.

 

[PaulJ2303]

here are a couple of screen shots of my configuration