Supply Issues with Arduino project

Projects General Guidance
1

Hello everyone!

This thread is a follow up to this project : Driving stepper motor with Arduino and A4988 - Project Guidance - Arduino Forum

I made a bit of progress since then by streamlining the code, adding a solenoid valve, a switch for the power supply, and I tried to implement remotely supplying the Arduino via its Jack port. Here is the current scheme of the circuit :

Just to clarify, the two wires coming out of the rotary encoder (on the bottom) are 2 extra pins for the central push button.

I am using a buck-converter (https://www.gotronic.fr/art-regulateur-ajustable-1-25-a-30-v-ef03061-23543.htm) as a way to step-down the voltage coming from the power supply (24V, 1A).

The issue that I am currently facing is that when I plug the whole prototype with the power supply, everything turns on no problem : the ON LED from the Arduino turns on, the Nokia 5110 screen turns on (but the backlight is very dim) and for some reason the motor starts slowly spinning although no command was sent to do so (The motor is controlled via a menu interface on the LCD screen)... But stops running after 2-3 seconds.

I instantly thought that this might be an issue from the buck-converter stepping down the voltage too much, so I tried to play a little bit with the screw from the potentiometer to change the output voltage, but I am afraid of destroying the circuit, and for the moment I do not have a multimeter available to test the output voltage.

I was just wondering if the problem was coming from the buck-converter as I mentioned previously or from the wiring diagram itself, maybe I fucked-up some of the connections? I wanted to have the point of view from experts!

P.S : the circuit that I was using previously, powering the Arduino with the USB cable and my laptop works perfectly! Here is a scheme of 'stable' version of the prototype :

If you have any ideas,

Thank you in advance!

Best,

Tom

Pump_Prototype.jpg
Pump_Prototype.jpg2793×1803 539 KB

2

Did you properly "tune" the buck converter to output the correct voltage?

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F**ing has a "schematic view". It will initially look like a bit of a mess but if you move the components around so that related things are near each other, you will get a diagram that is much more readable than the breadboard view.

The basic principle is to minimise the number of lines that cross other lines. Use ground and power symbols so you don't have ground and power snaking all over the diagram.

The schematic view also has the advantage that the part numbers are readable and the pins on the parts are labelled.

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Thank you for the very fast answers!

First of all sorry for the double thread, it bugged for some reason, I can't erase it now...

To reply to Power_Broker : As I mentioned I tried 'tuning' the potentiometer, but I'm afraid of increasing the voltage too much and I unfortunately don't have a multimeter available right now, I'll try it as soon as possible.

To reply to MorganS : I'll definitely output the circuit in "schematic view" it should look much better, thank you for the advice!

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@Tomtop, please do not cross-post. Other thread removed.

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Tomtop:
I'm afraid of increasing the voltage too much and I unfortunately don't have a multimeter available right now

.....and therein lies the problem. Voltage is too low. But as you said, you need that multimeter for tuning.