I have a pretty big automation project which has one problem: after I turn off 2 pumps and turn on 2 solenoids my arduino dies and stops executing code. I'm attaching the diagram which shows how everything is wired (notice, I did not include other components which work fine). Could you help me prev…

[image] avtem: after I turn off 2 pumps and turn on 2 solenoids my arduino dies and stops executing That's to be expected with that wiring. Motors and solenoids need kick back, free wheel, diodes.

Indeed! [image] Flyback diodes and why you need them General Electronics Any component that relies on an electromagnet or coil of wire for its operation will be inductive, that is the nature of coils of wire. Common examples are relays, solenoid and most types…

[image] avtem: notice, I did not include other components which work fine). While I am pretty sure @Railroader has identified the problem, missing things out is not a good idea because the things you missed might work themselves but be the cause of other things not behaving.

It would help if you read and followed the advice in the pinned post re 'How to get the most from the forum'. One thing you will learn is that kind of photo is not helping. The schematic is the instructioins, we want to know where YOU connected the wires. A simple hand drawn diagram of where every w…

Strange, why do so many tutorials don't even mention installing diodes... So I should put a diode on all solenoids, pumps and relay then?

[image] avtem: put a diode on all solenoids, pumps and relay then? All inductive loads needs it. Naked relays are electromagnets inside but the relay-modules usually have those diodes already. Motors and solenoids needs it even if relay fingers switch them. The sparcs/voltage kicks when switc…

[image] avtem: Strange, why do so many tutorials don't even mention installing diodes Because once they've got your page view they really don't care much if it works?

Welcome! It appears you are suffering from interference, and your pictures confirm that it is likely to be a serious problem. You have built a fantastic noise generator, not a controlled system. To get better help you need to post an annotated schematic showing exactly how you wired it. Include al…

[image] avtem: Could you help me prevent these voltage drops? Kickback diodes won't prevent voltage drops if that is actually the problem. Powering the Uno via the 5V output pin is usually not a good idea, especially if you don't have a well regulated and clean supply. I would power it via t…

[image] avtem: Strange, why do so many tutorials don't even mention installing diodes Because they are not always needed.

Arduino browns out after changing state of these 4 components

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PerryBebbington April 30, 2026, 7:22pm 3

Indeed!

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Arduino browns out after changing state of these 4 components

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