This project was submitted to 'Creative Electronics', a Beng Electronics Engineering module at University of Málaga, School of Telecommunications (https://www.uma.es/etsi-de-telecomunicacion/).

The idea of this project is given by the situation due to COVID-19 in which the planet is currently, that is why I wanted to give a touch of joy to a garment that has become a mandatory part of the wardrobe.

Autor: Carlos Fernández Mejías

Supplies

Arduino Nano.

Heat shrink wires.

Wires.

HandMade Mask (See the mask design step below).

330 ohm resistor (To prevent spikes on the data line that can damage your first pixel).

NeoPixel Wheel - 16 x WS2812 5050 LED RGB (You can configure a ring with more or less LEDs in the program).

Power supply for the Arduino Nano (See the Power supply step for more information).

Electret microphone .

Costure Kit (To make the mask if we make it ourselves and also to sew the components)

Of course you will aso need a soldering iron, flux and tin to solder the components.

Step 1: Mask Design

For this project I have decided adapt a handmade fabric mask, for this I have used a personalized design, you can find designs of all kinds on YouTube, in the image you can see the measurements that I have used for mine, although the measurements should change according to your size and the type of battery you chose.

Measurements are from a test mask I made for a larger face size.

I also recommend sewing the mask so that we have protection between the components and our face, for this I have decided to make an opening in the middle to be able to manipulate the components.

You will also need two rubber bands to tie the mask to your ear.

Step 2: Programming the Software

To implement the software, I used Adafruit's Neopixel library. You can find the library here:

https://github.com/adafruit/Adafruit_NeoPixel

You can find the software explained step by step in Spanish and English.

In the following github repository you can access the code used:

https://github.com/carlosfernandezmejias/Led-Mask

Step 3: Power Supply

In my design the Arduino Nano provides power to both the microphone (3.3V) and the led ring (5V), using the corresponding pins on the Arduino. To power the arduino we will use the Vin pin, it must be powered with a power supply between 6 and 12 volts.

In the schematic I have added a 9 Volts battery to save costs even though it is heavier, but you can also use for example a higher cost lithium battery, it will reduce the weight of the mask.

Step 4: Wiring and Sewing

You can see the schematic of the circuit in the image that I have left, obviously the position of the components will change when implementing them in the mask.

Connections:

3.3 V to microphone V+ pin.
GND to microphone V- pin.
Analog pin to OUT microphone pin.
Digital pin to Neopixel ring data input pin. (You should use a 330 ohm protection resistor between the pins)
GND to Neopixel ring Ground pin.
5V to Neopixel ring Power pin.

First I have sewn the led ring in the center of the mask, then I have made a hole next to the arduino nano to be able to pass the wires(this depends on how your mask design is), I recommend placing the microphone and the arduino on one side of the mask and the battery on the other to compensate a little the weight.

When soldering the cables to the components, I recommend using heat shrinks to protect the joints of the cables with the components and thus avoid damaging the circuit.

I also recommend being careful when soldering the components in the mask as we could stain it.

Step 5: Power Consumption and Weight

I am attaching a table with the consumption and weight of the components that I have used in this project. Two very important factors as we seek the balance between weight and battery life.

We also have to take into account the weight of the wires used and the adapter for the battery.