LED door bell

Hi guys

New to Arduino, but not coding itself. Moderate experience with circuits. I’m looking to create a replica of a unique door bell what’s shown in the below YouTube video. Multiple LEDs, flashing in sequence. Needing the patterns to cycle, start from the beginning and play a sound when pushed.

I’m sure the original has a custom circuit board inside, but to get started I want to build this with an arduino to understand the design. Any help getting started appreciated. Obviously I want to keep the design as small and slim as possible. Will an UNO suffice? Starting point greatly appreciated.



Does your door bell run on AC or DC? What voltage?


@Paul_KD7HB - the one in the video is 12v DC.

Paul - currently just wanting to have a functioning button with the LEDs and sound file to play. Actually making it a functioning “door bell” isn’t a priority at this point. More just a project to learn how to make it work.

my project started as a doorbell. it has grown massive, so there is no point in posting it here

what you need is:
a nano
a button
a debounce library
a sound card

the most practical sound card I have encountered is the Catalex YX-5300. onboard SD card, up to 256 folders, up to 255 files per folder. I use memorable sounds from my generation; movie and TV clips, commercials, music. you could push the button for hours and never hear the same sound twice.

@Geek Emeritus

Wow thanks for the info! I’ll look into your list when I order my arduino.

I have 33 LEDs I need to independently control - will an UNO suffice?

I would recommend a DFPlayer Mini for the sound. They are cheap, easy to use, and can drive a small speaker directly. Record the chime in MP3 format on a micro-sd card and plug it in.

I concur about the Nano. Uno will just be a pain to work with when prototyping. I don't think you need a button debounce library.

For the LEDs, it appears there is an outer ring of red LEDs, and maybe 6 groups of blue LEDs that switch on & off together?

With a 12V supply, you can organise your LEDs into sets of up to 3 in series, maybe 4 for the red LEDs. For groups with more than 3 LEDs, you will need multiple sets in parallel. Each set will need it's own series resistor, which will be a different value depending on the colour and number of LEDs in the set.

The voltage and currents involved are too high for an Arduino to handle, so you must use transistors to drive each group of LEDs. These can be ordinary npn like bc337, with 1K base resistor. Alternatively you could use a uln2003 or uln2803 chip, which is equivalent to 7 or 8 individual transistors.

I have 33 LEDs I need to independently control - will an UNO suffice?

That's not what is shown in the video you pasted the address of (not linked to, btw, it could not be clicked). It seems to show only 7 or 8 groups of LEDs, with 4 to 10 LEDs in each group, not independently controlled.

Apologies about the link - posting from my phone abroad. Expected it to hyperlink.

Yes, after another look it looks like the LEDs are indeed grouped. Will check out the specs on a nano once I’m back with my laptop!

Cheers guys!

Pasted addresses don't magically become links on this particular forum, even if you post them from Narnia or Middle Earth. But it's only one extra click to make a proper link.

Controlling 7-8 groups of LEDs with Nano or Uno is significantly easier than controlling 30+ individual LEDs. With a 12V supply, you cannot supply 30+ LEDs with 5V, it would cause the Uno/Nano's regulator to overheat, so it's important to combine them into sets of 3 in series and power them from 12V. But to do that, you need transistor drivers.

I agree with PaulRB here

Arduino Pro-Mini or Nano
DFPlayer mini
Leds of your choice.


AS far as driving the leds...it depends on how you set them up in the end.

They dont need (seem to?) change color.. so RGB or Neopixels are NOT needed..

HOWEVER.. Nepoixels might be a nice solution.. (might need the RGBW variants?) as they run off +5v.. and can be powered by the VIN pin (if the power source has enough current to drive the total led count)

OR.. you may need to some sort of transistor..

OR the use of a MAX72xx type chip.. (chip, and resistor.. runs of +5v as well)

@PaulRB - I appreciate your candor re the link :wink:

I appreciate all your input fellas. Ordered a Nano on Amazon so I can start playing with it when I get home in a couple weeks.

Question though, once each group is wired in parallel are the separate groups connected each via one of the 8 analog ports?

Question though, once each group is wired in parallel are the separate groups connected each via one of the 8 analog ports?

Are you asking about the LEDs? enhance your clarity.

Yes, each group of LEDs.

Do you have any other kind of electronic components?

If not.. a Nano wont get you very far (as is)..

Perhaps with a breadboard and some jumper wires. and some leds..etc..

Or an UNO.. because it already has female headers on it..

Actually.. I suggest you get both.. (and all the other stuff mentioned too)

Everyone needs an UNO! even if your final product/project will be ported/used with a Nano/Pro-Mini..etc

Look more into neopixels/WS2812 addressable RGB leds. They need 1 IO pin per string and can make regular colored led displays look lame.

If you run out of pins for leds, look into led driver chips though the best of those kind of deserve RGB leds.

Everyone needs an UNO!

I’ve never owned one and can’t imagine needing to.

If you want to fit a ready-made shield, get an Uno/Mega/Due.

If you want to build your own circuit on a breadboard, and then solder it up onto a pcb, get a Nano/Pro Mini/Teensy/Wemos Mini/Maple Mini/Itsy Bitsy/Feather…

You can breadboard DIP AVR's... and use an Arduino to program them.

One person in Japan doesn't even bother with the breadboard to make a Duino that plugs into breadboards or cables, etc.

My favorite breadboard Duino site includes the ATmega1284P which has 40 pins (32 I/O), 2 serial ports, 16K RAM, the biggest AVR made in DIP form (old style chip) for less than $6. It's a nice in-between for Uno/Nano/etc and a Mega2560.

Everyone needs an UNO!

I've never owned one and can't imagine needing to.

I generally advise in that direction.

However I do have a couple of UNOs simply for experimental use, such as testing the "Multi-function Shield" and "LCD Keypad shield" discussed here recently (each of which has a major design fault).

For practical/ useful projects, the Nano/ Pro Mini or WeMOS D1 Mini - even the ESP-01 for such simple things as a Times Square Display or relay control.

Okay guys. Got my nano. Have my LEDs.

I know LEDs typically draw 20mA. My biggest “group” of LEDs are red, of which there’s 14 connected in parallel. At various points in the code animation all LEDs will be lit (7 “groups” - or 34 LEDs. 1 group of red, 5 groups of blue and 1 group of green).

I’m concerned about the board being able to power all these, especially at once. I know each output on the nano will need a resistor but I’m still concerned that my larger groups of LEDs won’t have enough power?