Introduction: Desk Bluetooth Speaker With Audio Visualisation, Touch Buttons and NFC.

Hi there! In this Instructables I'm going to show how I made this Desk Bluetooth speaker which has Amazing Audio visualisation with touch buttons and NFC . Can be easily paired with NFC Enabled devices with just an tap. There are no physical button there, only just touch on wood at the top of the speaker where the volume+ and volume- had been indicated and booooomm magic happens!!.

The device incorporates two internal 15watts speakers one downward-firing and other up firing : a 2.5-inch (6.4-centimeter) woofer and a 2-inch (5-centimeter) tweeter. Woofer take up roughly the lower half of the cylinder. The air chamber above the speakers reportedly decreases distortion and enhances the tweeter's sound.

Your standard portable wireless speaker just won’t hack it if it is not designed to pump 360° omni-directional sound. This speaker delivers full 360° field of surrounding audio.

Step 1: Photo Gallery.

Step 2: Parts and Supplies.

  • 15watt 2.5-inch (6.4-centimetre) woofer
  • 15watt 2-inch (5-centimetre) tweeter.
  • PAM8610 Class D Digital Audio Power Amplifier Board.
  • Audio Bluetooth module.
  • 4700uf 16v Capacitor.
  • Arduino Pro Mini.
  • TTP223 Touch Sensor.
  • NFC Tag.
  • FTDI Breakout board.
  • 40x WS2182B Addressable LEDs.
  • XL4015: DC/ DC Buck Converter, 5 A/36 V
  • 12v 2A Power Adapter
  • 1x DC Barrel Power Jack/Connector.
  • Heat shrink Tubes.
  • 7x Brass Hex Standoff M3x15
  • 16x M3x8 Hex socket screws.
  • Frosted Acrylic cylinders lamp shades (200mm lenght x 94mm dia)
  • 1" PVC Pipe (180mm)
  • Cylindrical wooden block (OD: 94mm)
  • Wooden Plyboard (3mm x 100mm x 100mm)

Step 3: The Enclosure.

For the Enclosure type, I've selected cylindrical type enclosure.

The Frosted Acrylic Cylinder

The base is wood and is housing for the woofer speaker and the middle part is frosted Acrylic will helps in diffusing the 40 WS2812B leds used. The top part is also wood which holds the tweeter speaker into the place.

Step 4: Selection of Speaker Driver.

I've used a pair of speaker drivers, in which one is woofer and the other one is tweeter. Both are 15watt units. Since the audio signal is broken up into different frequency ranges to be sent to different speakers, it only makes sense that the speakers be designed to handle those frequency ranges. That’s where woofers and tweeters come in. A woofer is a speaker designed for low-frequency sounds and a tweeter is a speaker designed for high-frequency sounds.

A woofer is a speaker that is sized and constructed so that it can reproduce low or low and mid-range frequencies well (more on this later). This type of speaker does most of the work in reproducing the frequencies you hear, such as voices, most musical instruments, and sound effects. Depending on the size of the enclosure, a woofer can be as small as 4-inches in diameter or as large as 15-inches. Woofers with 6.5-to-8-inch diameters are common in floor standing speakers, while woofers with diameters in the 4 and 5-inch range are common in bookshelf speakers.

A tweeter is a specially designed speaker that is much not only much smaller than the woofer but is tasked with only reproducing audio frequencies above a certain point, including, in some cases, sounds that human ear cannot directly hear, but can sense.

Another reason that a tweeter is beneficial is that since high-frequencies are highly directional, tweeters are designed to disperse high-frequency sounds into the room so that they are heard accurately. If the dispersion is too narrow, the listener has a limited amount of listening position options. If the dispersion is too wide, the sense of direction of where the sound is coming from is lost.

Step 5: Base Part of the Unit.

The base part contains the woofer speaker driver as well as the power port, in my case which is an DC barrel jack.

After marking the location of the jack, I had drill the section using a 12mm Wood Flat Drills Bits.

Step 6: Adding the Dc Jack to the Base.

Barrel connectors provide only two connections, frequently referred to as “pin” or “tip” and “sleeve”. When ordering, there are three differentiating characteristics of a barrel connection- inner diameter (the diameter of the pin inside the jack), outer diameter (the diameter of the sleeve on the outside of the plug), and polarity (whether the sleeve voltage is higher or lower than the tip voltage).

After soldering both the wires, secured them using heat shrink tubing and placed the jack to its place and hot glued it.

At the end I trimmed the excess hot glue.

Step 7: Mounting the Woofer Unit to Base.

Here, first I've soldered the speaker wire to the speaker driver and then secured them using heat shrink tubing. I've kept the wire long enough to reach the main circuitry. Then marked the speaker unit holes and using 2.5mm drill bit, made the holes for the screw. After that fixed the speaker driver using M3x8 screws.

Step 8: 3D Print the Holder.

I've created a simple 3D file for the holder. Printed the file in PLA at 20% infill.

Using some hot glue mounted the 3D printed part to the base of the unit.

Step 9: Electronics.

  • Arduino Pro mini

Arduino works as the main brain for the audio visualisation. Analog Audio signal is converted in digital signals as per the code for the WS2812B addressable LEDs.

  • WS2812B Addressable LEDs

What’s great about these LEDs is that we can control even the entire LED strip with just a single pin from our Arduino board. Each LED has three connectors at each end, two for the powering and one for the data. The arrow indicates the data flow direction. The data output pad of the previous LED is connected to the Data Input pad of the next LED. We can cut the strip to any size we want, as well as distance the LEDs using some wires.

  • PAM8610 Class D Digital Audio Amplifier

The PAM8610 is a 10W (per channel) stereo Class-D audio amplifier with DC Volume Control which offers low THD+N (0.1%), low EMI, and good PSRR thus high-quality sound reproduction. The 32 steps DC volume control has a +32dB to -75dB range. The PAM8610 runs off of a 7V to 15V supply at much higher efficiency than competitors’ ICs. The PAM8610 only requires very few external components, significantly saving cost and board space.

  • XL4015 DC-DC Buck Converter

This DC-DC buck converter xl4015 voltage regulator board features an XL4015 step-down switching regulator capable of current up to 5A, capable of converting higher voltage to a lower voltage, without requiring additional power supply.

  • TTP223 capacitive touch sensor.

Here is a simple capacitive touch switch circuit for electronics hobbyists. Even though the circuit uses smd components, construction of the touch sensor switch is not very hard because the whole circuit can be easily fabricated on a piece of smd prototyping board. At the heart of the circuit is an inexpensive (`20) smd chip TTP223 commonly available in BA-6 package. The TTP223 is a touch pad detector IC which offers one touch key, designed for replacing traditional direct key button switch with diverse pad size. Low power consumption and wide operating voltage are the contact key features for dc or ac application

  • RFID/NFC Clear Tag - 1KB

This is a blank 13.56MHz Classic 'laundry' tag - often used for laundry or identification but also found in other systems where a small proximity card is desired. This one is clear! The tag contains a small RFID chip and an antenna, and is passively powered by the reader/writer when placed a couple inches away.

  • Audio Bluetooth Module.

The use of Bluetooth Stereo Audio devices has increased over the years with such modules being used in the various applications, with their use extending from vehicles to smartphones. These modules take in Audio data via Bluetooth and transmit it through Serial communication. This module has a supply voltage of 3.6V to 4.2V with current consumption less than 10mA in idle mode & 55mA in Active mode.

Step 10: Preparing the LEDs

Let’s start by taking a closer look at the LED strip. It consist of type 5050 RGB LEDs in which the very compact WS2812B LED driver IC is integrated. Depending on the intensity of the three individual Red, Green, and Blue LEDs we can simulate any color we want.

Here I've use total 40 LEDs to make a strip out of it. I know this individual are not great for the strip, but I've plenty of this individual laying around so I decided to use them

Note; WS2812B Led strip would be much easy if you are willing to use.

Step 11: Testing the Program

For programming the Arduino, I've used the FastLED library. This is an excellent and well documented library which enables easy control of the WS2812B LEDs.

Desctiption: So first we need to include the FastLED library, define the pin to which the LED strip data is connected, define the number of LEDs, as well as define an array of type CRGB. This type contains the LEDs, with three one-byte data members for each of the three Red, Green and Blue color channel.
In the setup section we just need to initialize the FastLED with the parameters with defined above. Now it the main loop we can control our LEDs anyhow we want. Using the CRGB function we can set any LED to any color using three parameters of Red, Green and Blue color. In order to make the change happen on the LEDs we need to call the function

Step 12: How Touch on Wood Works?

You can use it to detect and switch on external units. A capacitive touch sensor module based on the dedicated TTP223 touch sensor IC. The module provides a single integrated touch sensing area of 11 x 10.5mm with a sensor range of ~5mm. An on-board LED will give a visual indication of when the sensor is triggered. When triggered the modules output will switch from its output.

Here is the youtube video form where I got this idea.

Step 13: RFID/NFC Clear Tag Programming

This is a blank 13.56MHz Classic 'laundry' tag - often used for laundry or identification but also found in other systems where a small proximity card is desired. This one is clear! The tag contains a small RFID chip and an antenna, and is passively powered by the reader/writer when placed a couple inches away.These chips can be written to & store up to 1 KB of data in writable EEPROM divided into banks, and can handle over 100,000 re-writes.

I burn Audio Bluetooth's MAC Address onto the chip using Android APP called "NFC Tools".

e.g my Bluetooth MAC Address is C5:90:A4:EB:D2:F8

Step 14: Wiring

According to the schematic I wired up the buck converter, capacitor and audio amplifier using some long wires and secured them with heat shrink tubing.

Step 15: Adjusting Voltage for Arduino.

PAM8610 requires 12V of power, but the Arduino pro mini and WS2812B runs on 5V. So to efficiently lower the voltage level from 12V to 5V I've used the buck converter.

Before soldering the Power wire to arduino, I had set the voltage to 5V using the potentiometer on buck converter at given 12V.

Step 16: Volume Buttons.

The volume button on this bluetooth module shares common vcc line, so I soldered wire to each input line of the button for the touch buttons output.

Step 17: Installing the LEDs and the Diffuser

I rolled the LED strip from bottom to the top end and fix it using hot glue. Soldered the wire to the LEDs coming from the Arduino and secured it.

The cylindrical acrylic fits snugly onto the bottom wooden base.

Step 18: Fixing the Twitter.

Using 4x M3x8 hex screw I fixed the twitter in place and I've also drilled the hole according to the ring for the top part of the unit in which standoff will be inserted.

Step 19:

For the top most part of the unit I've used 3mm plywood with 100mm x 100mm sides.

Using coping saw I cut out the circle out of it as per the size of the ring, and using glue, attached the 3d printed ring to the wooden piece and drilled the hole for the standoffs.

Step 20: Installing the NFC and Touch Sensors

Using Hot glue I fixed the NFC and both the touch sensors to the bottom of the wooden piece and wired the touch sensors.

Step 21: Adding Standoffs.

Here I've used brass standoffs of M3x7. Screwed them to the drilled holes and attached the down ring using 4x M3x8 hex screws.

Step 22: Adding Rubber Feet.

Attached the rubber feet to the base of the unit to, secure from spillage and adding additional grip to it.

It also works as dampers, absorbing all the vibrations coming from the woofer unit.

Step 23: Marking of Volume Sign

At last using black marker I marked the sign of volume + and - where the touch sensor is present behind of the wood and the using Wood Wax, polished the wood.

Step 24: Plug and Play

Plugged and Powered the 12V 2A adapter to Speaker unit and the speaker is ready to rock.

♥ I hope you liked this project, let me know in the comments if any queries ♥

Thanks!! for Your support.

Audio Contest 2018

Second Prize in the
Audio Contest 2018