Fast reef pi build, I hope.....

[stefanm]

The objectives of this build,

Run my jebao dp4-s dosing pumps (this is the slave model and doesn't have a controller) I want to be able to run all four heads via a pca 9685 pwm driver.

Control 8 outlets, chiller, heater, sump lights, skimmer and pumps.

Later I may add my lights to the PCA 9685, right now they're running on a DIY version of storm X also on a PCA 9685 on an Arduino Uno, that'll need a full days worth of concentration and a lot of rewiring, so back burner for now.

So far I've mounted the pi, the l293d and the PCA 9685, just need to test the first of the l293d modules, if it works I'll set up the other one, then I'll move onto the temp sensors and the relay module. I have hopefully a few hours free to make some more progress.

 

[That Crusso Kid]

Looks good!

How big is the box you're using?

 

[stefanm]

Looks good!

How big is the box you're using?

Roughly 6.5 X 6.5" and 2.5" deep.

 

[stefanm]

The finished project should look like this, the power bar will have two more 2 pin sockets to supply power to the pi and another to the relay, which will have its own independent power supply. There's a 12 volt PSU in the power bar to supply power to the dosers.

 

[Diamond1]

Cool! I like the nice neat look and the small form factor.
Are you using the ADJ powerstip?

 

[Diamond1]

Never mind posted the ADJ question while you were posting....

 

[stefanm]

Never mind posted the ADJ question while you were posting....

I'm not in the US, one of those would have made my life easier.

This is the relay module I'll be using, it has a jumper for active high or low inputs, so hopefully I've covered everything, I've not tested it so hoping all channels work, I did see some mixed reviews on Amazon today regarding this.

I also picked up a panel mount stereo jack today, so can keep the temperature sensors separately from the other cables, this is all going under my tank, earlier this was all planned for an Arduino build with a touch screen and was to be mounted above the tank, so this is so much better especially as I have a ton of space under the tank (I have a remote sump) and wires can be shorter.

 

[Ranjib]

Following :-)

 

[stefanm]

Had a problem yesterday getting the l293d's to give any output, I was getting an error on gpio 4, so went back to the console and redid the i2c and 1 wire, also made sure the spi was disabled, I also changed the jumper wire incase of poor connection, also checked the output of the 12 volt PSU discovered it was giving 17 volts, so swapped that out too.

Hooked it up and had my daughter click run on the calibration screen, it worked got 8.4 volts at 70%, this was running two gpio pins, will have another attempt with a single gpio, if that works the dosing is sorted then I can move on to the relay module, hopefully I won't need the uln chip circuit, this is a 5volt module. Fingers crossed as my wife is getting p*ssed off with all the wires etc...

 

[stefanm]

Ok today I managed to test two of the outputs on the l293 module with a single gpio output per pump, all working as it should.

I also done a quick test on one of the relays, again no problem working as it should.

All I need is half a day without distraction and I can finish it all off, I'll probably need to split it up over the weekend, fingers crossed I can complete by Sunday evening....

 

[stefanm]

Two down, two to go...

 

[Ranjib]

These are the Jebao slave doser ?

 

[stefanm]

These are the Jebao slave doser ?

Yes, it cost approximately $40 after exchange rate from a local dealer here, cheaper than buying from China! now it seems that one of the l293d shields is faulty on one channel, I suspected this when I first tested it, just a simple job of swapping the chip over I hope.

Next issue I'm having is the relay module, screwing more than 1 wire into a terminal just doesn't work, anyway I found this terminal connector in my car audio spares box, going to hot glue it down and hook up everything individually, fingers crossed it should be all good.

 

[Ranjib]

I am seeing people using various pushin connectors in other reef-pi builds here in r2r

 

[theatrus]

Yes, it cost approximately $40 after exchange rate from a local dealer here, cheaper than buying from China! now it seems that one of the l293d shields is faulty on one channel, I suspected this when I first tested it, just a simple job of swapping the chip over I hope.

Next issue I'm having is the relay module, screwing more than 1 wire into a terminal just doesn't work, anyway I found this terminal connector in my car audio spares box, going to hot glue it down and hook up everything individually, fingers crossed it should be all good.

Those terminal blocks may not be big enough for 2 larger gauge wire (16AWG and up). If you do use terminal blocks for multiple wires, mechanically joining them (twist) before inserting makes sure the clamp holds both tight - but this is easier with stranded wire. Even better is crimping a ferrule over the stranded wire bundle.

I'd use Wago connectors (since Germany :)) to join the wires outside of the terminal blocks if you're using solid core personally.

 

[Ranjib]

@stefanm do you need any help here?

 

[stefanm]

@stefanm do you need any help here?

Its all working apart from a couple of things, as I mentioned on the main thread I was getting small shocks off a wire I'd removed and the 3.5mm stereo jack, so I've a feeling that one or two of the PSU's maybe faulty to some extent, I have a new 12 volt PSU for the dosers it has earthing on the AC input, for the 5 volts I'll either buy the genuine raspberry pi psu or a meanwell 3 amp PSU, I'm leaning more towards the meanwell as it also has earthing on the ac input, I just feel it's safer, especially as our mains power fluctuations are frequent here, along with daily power cuts, the pi and other kit is on battery backup, only lights and chiller aren't.

 

[Bigtrout]

The meanwells are a safer option...they are backed by a good manufacturer and in my testing alot more stable than wall warts.

 

[Ranjib]

The meanwells are a safer option...they are backed by a good manufacturer and in my testing alot more stable than wall warts.

I would echo that. I also think multimeter should catch stray voltage .. and lastly I’m not sure how to interprete the ac tester results for dc circuit

 

[stefanm]

I would echo that. I also think multimeter should catch stray voltage .. and lastly I’m not sure how to interprete the ac tester results for dc circuit

Yes the AC tester thing is whack, although humidity is low right now and I was wearing socks yesterday on a tiled floor and have a cat, could be static, though the doubt it, I'll replace the PSU's hopefully this week and report back.