VU Meter With GlowDuino

This is a super simple way to visualize audio in a mesmerizing way with the GlowDuino Uno microcontroller board.

Supplies

You only need a few things:

-A GlowDuino Uno board for display:

https://www.glowduino.com/shop/p/uno

Or at:

https://www.tindie.com/products/glowduino/glowduino-uno-a-better-arduino/

-An audio jack for input:

https://amz.run/6QMH

-An aux cable to connect the circuit to a source:

https://amz.run/6QMI

Step 1: Wiring the Audio Jack

No matter where you get your audio connectors, you need to determine the pinout of the connectors. On a 3pin audio jack, the pinout is as follows:

The tip is the Left Channel

The middle ring is the Right Channel

The sleeve of the connector is the Ground

At this point is a good idea to use jumper wires that can be directly connected to the microcontroller. I soldered my wires to a jack connector on one side and left the pins at the other end, but you can also get connectors where soldering is not required. A link for that is above in the supply list.

Step 2: Connecting the Audio Jack

When the audio connector is ready to use, it is time to connect it to the microcontroller.

Connect the ground wire to one of the GND pins of the board. Connect the other two wires to one of the analog inputs of the board. I used A6 and A7, but you can change the pins used in the code later.

Step 3: Editing and Uploading the Code

// Replace A6 and A7 with the pin of your choice
// Audio inputs (analog pin):
#defineLeftChannelA6
#defineRightChannelA7

// Here you can set the maximum and minimum levels.
// 0 is 0V and 1023 is 5V. 
// Set the range of input voltage
#defineMinimumVolume0
#defineMaximumVolume350

// Uncomment if you want stereo inputs
#defineStereo

In order for your setup to work as you like, you can edit the top half of the code.

The first thing you want to do is set which pin you are using. The default in the code is A6 and A7, but you can use any analog pin you wish.

Then you need to adjust the volume levels. Audio levels typically range between 0 and 2V, but it changes with every device. To match the volume of your own device, you need to adjust these levels. Just choose two numbers, upload the program, and see if it matches the volume of your device. If you see too many lights or too few, you can choose a different value and correct the measured volume level.

Lastly, if you have only one channel input, you have to comment out the "#define Stereo line" with "//".

If you are using the stereo mode, each channel will have 6 LEDs and will move from the outside to the middle. If you are using the mono mode, then that one channel will use 12 LEDs and move from right to left. Also notable that in mono mode, the dominant channel is the Left. So if you only connect one channel you need to define the Left Channel only.

Once ready, you can hit save and upload the program to your board.

Download the code from the file below to edit.

Step 4: Ready

Checkout the video: https://youtu.be/Wq9Tn1E1nkE

And you have a functional volume meter just like that.

One advantage of the GlowDuino board here is that you don't have to connect anything else for it to display the audio. Thanks to its onboard LEDs, you can have a neat and tidy board.

Sit back and watch the mesmerizing LED show!