Introduction: Analog VU Meter and Clock (Arduino Powered)

Picture of Analog VU Meter and Clock (Arduino Powered)
This project brings back the old time Analog VU Meter, with the added functionality of a neat looking clock! When you turn off your music the meters automatically swing into to clock mode. Behind it all is the popular and easy to use Arduino.

This is my submission for the Make-to-Learn Youth Contest:

What did you make?
I made an old style analog VU meter and Clock using 2 analog panel meters, an Arduino, a real time clock, and other simple components. How it works: The unit plugs into a standard 3.5mm speaker jack. The Arduino reads the sound levels and converts it into electric pulses (PWM) to control the analog meters. When no sound is detected, the unit automatically changes to Clock mode and displays the time which is read from the real time clock circuit.

How did you make it?
I got the idea to make an analog VU meter from seeing them used in older audio receivers and amplifiers. I was always intrigued by the effect of a needle “dancing” to the beat of music. With my basic knowledge of electronics and the Arduino platform, I decided that I could make one myself. After searching around the internet to see if anyone had done anything similar, I found that many people create Clocks with analog panel meters. Well, why not include both functions?

Where did you make it?
I made this at home by myself. I like to listen to music a lot and I am always tinkering and playing with electronics. I thought that this would be a fun project to compliment my speaker system which I also built myself.

What did you learn?
I learned a lot from this project. The hardest thing to get right was the programming. I have never worked with analog panel meters before, so getting them to display time and sound accurately was challenging. For example: It was hard to get both meters to point exactly straight up at 6:30. I also learned that connecting the Arduino directly to an audio source can distort the audio. To fix this, I added some resistors and the distortion went away.


Step 1: Materials

Picture of Materials

Shopping List:

- 2, 5v Analog panel meters (Amazon) or (Amazon)
- Arduino (I used the pro mini) (Amazon)
- DS1307 Real time clock (Amazon)
- Protoboard (Amazon)
- 10K potentiometer (DigiKey)
- 2 tactile switches (DigiKey)
- 4 10K resistors (DigiKey)
- 4 white LEDs (optional) (DigiKey)
- USB cable (DigiKey)
- 3.5mm cable (DigiKey)

Total cost is around $47. It will be less if you have some of these parts already.

Step 2: Meter Lights

Picture of Meter Lights

This step is completely optional, but I decided to put some lighting inside my meters.

First, I took the covers off the meters and drilled two small holes for the LEDs. Then I simply hot glued the LEDs into place. Be careful when drilling and hot gluing because the inside of the meters are relatively fragile.

It is better to use diffused LEDs for this application, but I did not have any diffused white LEDs around. So, I diffused some clear LEDs by using some sandpaper.

Don't forget resistors!

Step 3: Assembly

Picture of Assembly

The assembly is pretty straight forward. See the pictures for more details.

Note: If you only want to use it as a clock, you do not need the audio cable or the potentiometer.

Wiring goes as follows:

- USB red wire (5v) to VCC
- USB black wire to GND

- 3.5mm Audio left channel to 10K resistor to Analog 1
- 3.5mm Audio right channel to 10K resistor to Analog 2
- 3.5mm Audio ground to GND

- Potentiometer to Analog 0 (follow potentiometer wiring)

- Buttons - Left/Down to Digital 2  (follow button wiring)
                 - Right/Up to Digital 3

- DS1307 RTC  - SDA to Analog 4
                            - SCL to Analog 5

- Left Analog Meter to Digital 5 (PWM)
- Right Analog Meter to Digital 6 (PWM)

Step 4: Programming

Picture of Programming

The programming for this is relatively simple, but the hardest part is getting your meters to display time accurately. For example, when it is 6:30 both meters should be pointing straight up. Because all meters are slightly different, the PWM values need to be adjusted based on your design. Feel free to use my code, but you will have to change some values because it is set to work specifically with my meters

To program the Arduino Pro I used my Arduino Duemilanove because I don't have a FTDI programmer. Just remember that if you use your Arduino, you have to remove the Atmega chip before you program a separate device.

The code is not perfect, but it works. I don't have a whole lot of programming knowledge, so let me know how I can improve it.

If you only want to use it as a clock, download the ClockONLY code.

Step 5: Enclosure

Picture of Enclosure

I decided to make the enclosure with only two pieces of wood. I drilled out the holes for the meters, painted the base, and screwed on a thin piece of wood which I covered in a thick felt material. I chose this design because it  was easy to build and allows easy access to all of the electronics.

Step 6: Custom Meter Backgrounds

Picture of Custom Meter Backgrounds

Because these meters have to display time, I had to customize the backgrounds. I scanned the back plate of the meters and used MS Paint to create a custom background. Then I printed the design on card stock paper screwed it in place. You can download the designs that I have attached below if you have the same or similar meters.

Step 7: Finish!

Picture of Finish!
It's finished! Plug it into a USB port and plug the audio cable into a jack splitter. Set the time using the buttons and adjust the audio sensitivity with the potentiometer.

Thanks for reading!

Please consider giving me a vote in the Make-to-Learn Youth Contest!

See the video:


andrea biffi (author)2017-06-12

awesome! I wish to make it

ArunK197 made it! (author)2017-02-01

Great Project and I did it..but seem to have couple of problems. Can some one help me to understand what the POT is for?

Second I am not sure what is the time being displayed , is there a way to know the time being sent from Pro Mini ATmeg168.

The 2 switches seem to have no effect when pressed. Also when I try to move my hand close to the switch the time seem to fluctuate and change , its the same with the touching the audio jack.

I used the "FTDI FT232RL FT232 USB TO TTL 5V 3.3V SERIAL ADAPTOR FOR ARDUINO" to program the AT168, One problem I saw was programmer not ready issue, and posting the solution if its useful for someone else. To resolve the issue I choose the correct board in the Audirino IDE and changed the Serial Speed to 19200 in the com port settings on Windows 10.

Any help is appreciated. Thanks

evan.stoddard (author)2013-07-12

Hey I updated your sketch so the person only needs to enter the voltage of their meter and all the math is done automatically... I can send it to you if you want

ArunK197 (author)evan.stoddard2017-02-01

Can you please provide a link to you code please.


edwardo388 made it! (author)2015-12-25

So I made this kind of last minute for my dad for Christmas. I hurried and it's not the best, but fully functioning! The ATMega2560 is way more than this project required, but the only microcontroller I had available at the moment. Ironically, my dad saw a kickstarter campaign offering a more polished version of my analog meter clock and thought it would be a unique gift for me.. so we gave each other the same gift essentially. I still think I won...

hycday (author)2015-09-01

Hi !

awesome project :) I could manage to get the clock working, however, no way of reading the sound from an audio jack...I looked everywhere on other websites/forum/guides etc, no way of catching the ouput from an audio jack, sending it to the arduino, reading it with analogRead and doing something with it...any hints ?

Thanks a lot for your help

Joohansson (author)2013-09-03

Awesome project! I wonder about the reason for your strange scale between 7 and 10 hours?

ChrisE3 (author)Joohansson2015-01-24

The reason is that, on a scale of 1-12, 6 is not in the middle. The gap between 6 and 7 should be at the centre. If you want to have 6 right at the centre, the scale should start at 0 (e.g. for midnight) and the code would need to be tweaked to handle the difference between midnight and noon. Otherwise, adjust the 'hours values' to get a truly linear scale with the 6-7 gap in the middle.

Nice project!

benellisor (author)2014-05-24

having a voltage problem on both the hour and minute meters.

voltage from arduino pro mini will not produce full scale 5vdc.

currently my full range voltage is 0-4vdc. i assume this is a code issue.

if anyone has an idea please let me know.

Zabala (author)2014-03-26

Hi, its great!! i have a analog pannels and you give me an idea. Thanks

So... where is the code and the draws for a pannel? do you have it?

Zabala (author)Zabala2014-03-26

ok i found it, thanks

sBlended made it! (author)2014-02-21

Hello! Great instructable!

One tip for the owners of arduino leonardo: The SDA and SCL ports have to be connected to digital 2 and 3 respectively.

More info here:

(yap, it took me kinda time to figure it out and I thought I had made a mistake :P)

tech-e (author)sBlended2014-02-26

Awesome job! That enclosure is sweet!

licas (author)2013-10-24

Congratulations for your idea.
It´s possible to change the project to make a 5.1 (6) vu meters?

Thanks, Luis

DillyDog (author)2013-07-20

Can you modify the code for seconds and am/pm. I've got a great design in my head but it needs 4 meters!

jdmartin (author)2013-05-25

VERY nice, but does this clock need to be connected via the USB port all of the time, or just during initial setup?

tech-e (author)jdmartin2013-05-25

Thanks! The usb cable is only used for the 5v power. You can also use a 5v wall adapter or plug the usb connector into a usb wall charger.

kimips (author)2013-05-23

Can I make it without the rtc module (i don't need the time)?

tech-e (author)kimips2013-05-24

Yes, you can. If you only want the VU (sound meter) function, just delete all of the code below line 204 in the analogVU_Clock code. Just make sure you leave in the last curly bracket at the end or it will not work.

skavoovie (author)2013-04-26

Would you mind sharing what font you used for your customized panel meter face plates?

tech-e (author)skavoovie2013-04-27

The font is Commercial Script BT

jdhartman (author)2013-03-28

Everything seems to be working for me but the meters are running BACKWARDS! ???
Any thoughts? The serial monitor shows the time is incrementing and decrementing correctly when the appropriate up or down button is pressed. Also the
The meters go high, then low during the startup as they should.

tech-e (author)jdhartman2013-03-28

Check your polarity on the meters. Switch the wires around and give it a try. Also make sure the meters are hooked up to PWM pins on your Arduino. If that is not the problem, open up the Fade example sketch and see what your meters do (remember to change the pin).

jdhartman (author)tech-e2013-03-28

Updating here in case someone else runs into this. Thanks for helping me troubleshoot this today. Kudos to the author- A young person that is going to be successful. The Ardunio Uno requires that a (-) negative value be used for the meter values.
analogWrite(leftMeter, -X) Where x is the chosen value for each instance

---also include negative as shown here----
if (minutes * -4.75 < 255){ // increase PWM value by 4.75 each minute
analogWrite(rightMeter, minutes * -4.75)

bvbernard (author)jdhartman2013-04-14

The value parameter used in analogWrite is an unsigned byte (0..255). I think there is something else going on in either your code or the connections. I've done a similar clock using the Uno with 4 VU meters (Hours, Minutes, Seconds & Moon Phase) using a GPS receiver for time sync. It did not need a negative value.

I want to give thanks to the author as well. He inspired me to do my own version. Thanks.

astroboy907 (author)2013-04-06

What grade are you in? Im in 10th. Nice to see someone younger who does this kind of stuff. I actually have wanted to build one of these with the meter for a while

fredlb (author)2013-04-04

It's great ! I want to make the same !

stumitch (author)2013-03-26

Well done! esp that it is an entry in the youth contest. excellent!

kenyer (author)2013-03-26

cool that you made this. I have this idea in my idea-book for a long time now, but it is so cool to see that someone else had the same idea and really made it!

godfish (author)2013-03-24

This is great.

One thing that would be nice, If an estimate of cost on projects, I've been wanting to make one of these but the cost is what's stopping me.

tech-e (author)godfish2013-03-25

Based on the list the total project cost is around $47 without shipping. If you have some of these parts already it would cost less. You don't need to buy a new usb cable if you have an old one laying around.

mid_life_crisis (author)2013-03-25

That is seriously cool. I keep telling myself to start playing with Arduinos: this might just be the motivation I need.

AJMansfield (author)2013-03-24

You should add a third and fourth meter, one to track seconds, and one that ticks with the seconds like an old-fashioned metronome.

danbemp (author)2013-03-24

This is awesome!

nsilverman (author)2013-03-24

How do you program it? What program or device do you use? I am confused on this step. Please help.

lordzamiel (author)2013-03-24

You forgot the last sentence in step 5: "And looks awesome." Great job!

chabias (author)2013-03-24


twighahn (author)2013-03-24


agis68 (author)2013-03-24

its really nice.

wbrodyjr (author)2013-03-24

This is fantastic! Very creative. I'd be happy just to have it as a clock. The VU meter feature is just frosting on the cake.

onemoroni1 (author)2013-03-24

I love this, original thinking outside the box, modern and retro.

royboy (author)2013-03-24

I TOTALLY want one for my studio

wilsonpv (author)2013-03-24

Muito criativo,parabéns.

vicnur (author)2013-03-24


demonicmember (author)2013-03-22

Do the meters adjust independently for LEFT and RIGHT audio? It does not appear as tho they do. That would be a cool addon

You can see in the video the meters are independent for left and right channels at about the 40 second mark. The right falls while the left meter remains towards high.

tech-e (author)demonicmember2013-03-22

Yes they do. It is hard to tell in the video, but they do work seperately. Left channel to left meter and right channel to right meter. It also depends on the music because some music is more balanced between left and right.

About This Instructable




Bio: Hello! I'm a high school student and I enjoy playing with electronics!
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