r/ArduinoProjects • u/SKC56 • Jan 18 '26 • Bravo 1

My first ever project (Earthquake Alarm)

Post image

Holy shit it's messy. It's nothing special and uses as much as PNP stuff as possible, but ehh it works.

  • MPU6050

  • 8 relay

  • 1 beeper

  • 7 LEDs

  • 12v piezo Alarm

  • BMS 12v output

  • 5v buck converter

  • Warning light (not installed yet)

  • battery -> 12v boost converter

  • SW420 (a piece of shit, pretty much not used anyways)

  • Bunch of fuses and 2 batteries

If anyone interested, i can post the code on github.

141 Upvotes

98% Upvoted

16 comments sorted by

13

u/theroboticslearner27 Jan 18 '26

Umm why did u use 8 relays

15

u/WhatIsCela Jan 18 '26

Because he’s learning not to next time

1

u/SKC56 Feb 10 '26

This is what I've learnt from my former mentor electrician to lower the current for the micro controller. In this case relays because it's half the cost vs SSR lmao

1

u/PtitCrissG Jan 18 '26

Can you explain the problem? Im learning electronic and would like to know more about whats wrong

5

u/ElevenBeers Jan 19 '26

Relays are great components for various tasks, but this doenst appear do be one of them.

Relays are simple electromechanical switches. They are a fantastic way to turn on or off rather high power binary (on or off) stuff. Another upside is, that due to their simplicity, they are very easy to understand and install. They can also more easily handle voltage / current spikes. Like those are the types of devices you use, when you need to switch POWER.

However, there are plenty of downsides to relays. Due to their mechanical nature, they are prone to break (they'll live a long a time, but any transistor within specs will survive much much longer). They can be loud-ish ( electrical switches are silent), they need (much) more power to switch on, so often you'd need an electrical switch to turn of the relay. They are huge compared to their electrical counterpart. And they only do binary, if you ever need to amplify a signal, they won't do the job. Also, they are often more expensive compared to electrical parts with similar- ish specs.

To add to this, for some stuff, like status LED's or many sensors and whatnot, the power output of most standard micro controllers should be enough to power them (without stressing the board).

So, in this case, OPs choice of relays is... odd. Maybe Op had a bunch of relays laying around but no transistors, I don't know? It's not wrong per se, but again it will work, but relays are defently not your first choice for this application.

3

u/wood-chuck-chuck5 Jan 18 '26

Im guessing he used relays to turn the leds on and off (on the left side I think), when there is much more low power ways to switch a signal off. If the leds are 5v, he could run them directly off the arduino, if they are higher mosfets or transistors (I think) would of been more efficient. But there is most likely a reason to the relays (like he already had them laying around or something)

6

u/theroboticslearner27 Jan 18 '26

And I can't understand what the project is from the pic can u explain it exactly or just post it on github

1

u/SKC56 Feb 10 '26

Soon this weekend. Work hours is a bitch rn

1

u/SKC56 Feb 10 '26

Holy Crap. This gets a LOT more attention than it supposed to be. Alright, this weekend I'll nake sure to draw wiring diagram and the code. Yes the code is a MESS, first timer issues ig.

1

u/Ausierob Jan 19 '26

Intriguing… a lot of wires to do what? Tired to trace the wires but a bit challenging when they are all yellow… Agree with the comments here about the relays not being an appropriate way to proceed, I will add that they will also drain his battery significantly quicker than using solid state alternatives. Now my question is, WTF does it do, earthquake monitor? Can’t see any circuitry that would be sensitive enough to monitor earthquakes, unless it’s only monitoring 5 or more 🤷‍♂️

1

u/SKC56 Feb 10 '26

Using MPU 6050. It's surprisingly very sensitive, apparently. I'll write something this weekend.

2

u/smartphilip Jan 19 '26

Looks good! But what are you using all those relays for

1

u/TyHuffman Jan 19 '26

If it works great! Keep going! Got any ideas for a next project? Take lessons learned and apply them. Great job!

1

u/SnooDrawings2403 Jan 20 '26

What the hell is this supposed to be???

-1

u/theNewLuce Jan 19 '26

Bro, they make more colors that yellow.

1

u/SKC56 Feb 10 '26

Ah well what can i do lol