So I'm building a little controller that I want to function 4 devices, I want to have 4 outlets in the cabinet.
So it would house an Arduino, a relay, and the outlets
Any tips?
electrical project boxes; Arduino; electrical
So I'm building a little controller that I want to function 4 devices, I want to have 4 outlets in the cabinet.
So it would house an Arduino, a relay, and the outlets
Any tips?
What are you trying to power and what are you trying to control. Start with control, then design the power. You will never go wrong with that principle in circuits.
what are you controlling? and why not use a bus instead of receptacles?
Because I want to be able to unplug the devices and put them up
The devices will be two electric ball valves, a water pump, and a jacuzzi pump
It is to wash lettuce, drain the tank, filter the water, refill the tank, turn back on agitator (jacuzzi pump) and repeat.
Basically removing a lot of tedious work for me washing aphids off my lettuce
So I only know USA electrical, and I'm going to assume you're in the US. If you're a euro somebody else will have to translate.
Don't use a residential breaker box. Instead, use a box with DIN rail and some UL489 breakers like Eaton's FAZ-C15/1-NA-SP. Refer to NFPA 79 for conductor sizing (free to read with a free account). You can buy a bracket for the Arduino on McMaster-Carr.
>it's for washing things
Make sure to put GFCI receptacles in, and take care to waterproof the box. The NEMA category rating you should shoot for is Type 6. You might consider using waterproof industrial-style connectors and bulkheads for your devices, and keeping the GFCI internal to the box with something like the pictured item.
Repurpose an old computer UPS. You have a nice plastic cabinet with fitted heavy duty cord and 4 - 8 integrated outlets.
that's all well and good on the factory floor with a big companies budget and safety inspectors to suck up to, but I doubt OP wants to spend $1000+, he is probably a small-time farmer / homesteader
Well, you don't technically have to have a breaker in the box so long as all the wires can handle 20 amps and it's on a 20 amp circuit, and if you always plug the box into a GFCI receptacle you don't have to have one inside the box either. If he's in the US, both of these things can be taken for granted, because the sink should have GFCIs near it anyway.
The box should absolutely be waterproof, though.
Buy some aphid lions.
Always curious to see what people want to mix Arduinos and relays for...many ways that can go wrong.
Im seeing these controllino things more and more in semi professional projects. Guess they are okay if they’re in a box and it needs to do stuff that a zelio can’t.
DIN rail with outlets, cheap din breaker. Tiny Eaton boxes with din rails are cheep and ip67 rated. Tiny Rittal boxes come with cable glands and are better but not cheap.
Cool project btw
ABB HAF breaker
IEC60364 or VDE0100 (but just lookup IEC wire size chart).
Also if Europe and it’s going to have a plug, make sure you get a two pole breaker, because you can’t tell line from neutral on a euro socket
>controllino things
yeah a properly made board with optocouplers and shit is one thing, but a homegamer just sticking a relay on a gpio is a different story.
What do you mean? I'm using four relays for my current Arduino behemoth. It is supposed to control a 3.33A heating cartridge and three 1A peristaltic pumps. Is this a bad idea?
When I've combined this many instruments in the past, I've noticed finnicky behavior. When heaters turn on and off, for example, the Arduino LCD may dim or display gibberish. I've suspected that this is due to insufficient power to the system but don't want to needlessly buy high-amperage supplies for safety.
>I've suspected that this is due to insufficient power to the system but don't want to needlessly buy high-amperage supplies for safety.
It isn't needless if the circuit needs it to operate properly; you might just need more capacitive filtering at the right places. And yes, that idiot who implied that avrs and relays are a bad mix is wrong. They work fine together when you design properly, and driving a relay properly is not difficult, and there are plenty of sites that show how.
Depends on the relays and which arduino you're using. You may need flyback diodes and drive circuits.
My confusion is that I'm using two Arduinos, with the only mutual connection between the two being at the serial pins 0 and 1 for communication. When I have these relays turning pumps on and off, both of the relays display gibberish characters and I'm not sure if that's a result of gibberish getting sent between the two?
I haven't ever tried flyback diodes or drive circuits and have started to look into those, so thanks anons.
A written description of the device is as follows:
>Arduino 1 receives input from the user in terms of a target pH and a target temperature and displays a menu through which these changes can be made.
>Arduino 1 sends targets to Arduino 2
>Arduino 2 then measures pH and temperature
>Arduino 2 uses acid/base pumps and a heating cartridge to modify pH and temperature
>when pumps turn on, both Arduinos display complete gibberish
>Arduino 2 then measures pH
I want to be able to do this. Could you please describe your setup, with part names/numbers? Thanks.
Sure thing, here's a list of my materials:
-Atlas Scientific Gravity pH probe/sensor
-20x2 LCD screen (which I had gotten a 20x4)
-3x digital buttons (QTEATAK tactile) for controlling target pH
Measuring pH is actually stupid easy. It takes 5V from the Arduino to power the sensor, you plug it into A0 on the Arduino, and there's a lot of sample code online to do the rest. The only hassle is that you have to recalibrate it every time you turn it on, but that's the world of pH sensors for ya.
Here's a circuit sketch for what I'm describing. Can someone offer me some feedback on to diagram itself as well as the design if it's even legible? I took a basic electronics class but that wasn't enough to train me to write a good diagram.
Are you powering the pumps from the 5V on the arduino? 80 mA is probably their nominal rating and they maybe be pulling a lot more on startup and it's making the arduinos reset. That's quite a clusterfrick to look at btw.
Yeah, they're all powered by the Arduino 5V. What would you recommend as an alternative while keeping the one power supply? Your suggestion seems plausible and I didn't consider that the current draw of the relays themselves would be a problem.
Thanks for the tips. I will order some flyback diodes. These would effectively prevent current spikes when the instruments are turned on and off, but would not prevent the relays themselves from spiking in current, right?
Yes, the temperature probe is digital and reads no problem.
Thanks for the advice and for dealing with my amateur design
Regarding the relays, they dont spike the current, but the voltage across the coil when you turn it off. The flyback diode will clamp the spike and give a path for the coil to deenergize. I suspect youre just getting lucky its not blowing up your transistors or 5V rail the way you have it hooked up sinces there are several paths to "absorb" the spike.
The current will spike when the pump is turned on...or worse if both turn on at about the same time. This could be resetting the Arduino or eventually blow the 5V. If youre already cutting it close the limit with everything hooked up, you should probably add another 5V supply for the pumps.
So do you reckon this would get the job done? I've been told flybacks need to be connected in parallel, so I'm assuming this applies to all components and uses.
Yes the diode should be reverse biased across the pump. What you drew in the diagram is a bit fricky though. When the relay is closed have the pump hooked up to 5V and leave it floating when the relay is open...cover that terminal with some goo (if you ground it you're just bypassing the diode)
Also flybacks on the pumps may be a good idea as well
Also power the relay coils with the arduino? Are they solid state relays?
the relay coils need flyback diodes. they are not optional.
you don't have to draw 5v red trace and ground black trace all over the place. just label the 5v pins and draw lots of small ground symbols.
I see the temperature probe going to a digital pwm pin instead of an analog pin. Is this intentional?
>Arduino, a relay, and the outlets
just one relay? not four?
It's a 4 channel relay
You can just get rf controlled relays that come with a wireless remote off ebay for 20$.
Anyone know when Square D moved from raised amp rating to the white screen print we have today?
If it has a code on the label this pdf might tell you when that one was made https://inspectapedia.com/electric/Square-D-Electric-Panel-Age-Codes.pdf
Other related stuff https://inspectapedia.com/electric/Electrical-Panel-Age.php