LED Spectrum FM Bluetooth Audio Speaker DIY Kit

Introduction

This document describes the LED Spectrum FM Bluetooth Audio Speaker DIY Kit, a project designed for users to gain a better understanding of electronic circuits and develop soldering skills. The kit features a 12-piece LED spectrum display that visually represents music rhythm, offering a dynamic lighting effect. It supports multiple audio sources including FM radio, Bluetooth-enabled devices, AUX input, U-disk, and TF cards, powered by 3W 4ohm speakers for clear, loud sound.

Features

1. Multi-Audio Source Selectable

The device supports various audio inputs: Bluetooth, FM, AUX, U-disk, and TF Card. It can play MP3 or lossless music files, with a screen display indicating the current audio source. Playback functions (play/pause, next/prev, volume control) are accessible via the remote controller or onboard buttons.

2. Bluetooth Player

Equipped with a built-in Bluetooth audio receiver and power amplifier, this device can directly drive 4ohm 3W speakers, delivering clear and high-quality sound.

3. LED Spectrum Display

Features 12 pink, blue, and green LEDs that flash in sync with music, creating a dynamic visual effect. The LED audio indicator flashes at both ends simultaneously, with adjustable sensitivity via a potentiometer.

4. Dual Channel Stereo Speaker

The system can drive two 3W speakers, providing clear and powerful stereo sound.

5. DIY Hand Soldering

This is a DIY kit requiring manual installation of components. It is an excellent educational tool for electronics hobbyists, beginners, and students, enhancing soldering skills and fostering interest in electronic technology.

Parameters

Use Methods

1. Power Switch

Use the Red/Black Switch to turn the power supply ON or OFF.

2. Audio Mode Selection (MODE Button)

Press the MODE button to cycle through playback modes: Bluetooth, FM, AUX, U-disk, and TF Card. For U-disk or TF Card playback, ensure the media is inserted first.

3. Music Control (SCAN Button)

Short press the SCAN button to play or pause music. Press and hold for 3 seconds to initiate automatic radio search in FM mode.

4. Volume Up (VOL+ Button)

Short press VOL+ to switch to the next track. Hold VOL+ for 3 seconds to increase the volume.

5. Volume Down (VOL- Button)

Short press VOL- to switch to the previous track. Hold VOL- for 3 seconds to decrease the volume.

6. Volume Adjustment (Potentiometer)

The potentiometer is used to adjust the volume and is operated with a screwdriver.

Component Listing

NOTE: Users can complete the installation according to the PCB silk screen and component list.

Schematic Diagram for LED Spectrum Indicator

A schematic diagram is provided, illustrating the electronic circuit layout for the LED Spectrum Indicator. This diagram details the connections and components used in the circuit.

Application

• Training welding skills
• Student school projects
• DIY production
• Project Design
• Electronic competitions
• Gift giving
• Crafts collection
• Home decoration
• Souvenir collection
• Graduation design projects
• Holiday gifts

Installation Tips

1. Prepare Welding Tools

Ensure you have the necessary tools ready before starting:

• Soldering iron (under 50 Watt recommended)
• Rosin core ("radio") solder
• Wire cutters
• Wire strippers
• Philips screwdriver

2. Patience During Installation

Wait patiently until the installation process is fully completed.

3. DIY Kit Nature

This is a DIY kit; the user is responsible for completing the installation.

4. Component Handling

Exercise caution when using the soldering iron. Prolonged contact with components may cause damage. Always take note of component polarity for correct installation. Avoid short-circuiting.

5. LED Installation Guidelines

Install LEDs according to specified guidelines to ensure they light up correctly. It is recommended to install complex components first and ensure all components are oriented and placed correctly.

6. Pre-Installation Checks

Verify that all LEDs are functional and light up after installation. It is advisable to review the installation manual before commencing.

7. Anti-Static Precautions

When handling electronic components, wear anti-static gloves or an anti-static wristband to prevent damage from static discharge.

Installation Steps

Step 1: Install 5pcs 510ohm Metal Film Resistor

Install five 510 ohm metal film resistors at PCB locations R5, R13, R14, R17, and R18. The color bands for these resistors are green, brown, black, black, and brown.

Step 2: Install 4pcs 100ohm Metal Film Resistor

Install four 100 ohm metal film resistors at PCB locations R7, R8, R11, and R12. The color bands are brown, black, black, black, and brown.

Step 3: Install 3pcs 5.1Kohm Metal Film Resistor

Install three 5.1K ohm metal film resistors at PCB locations R2, R4, and R6. The color bands are green, brown, black, brown, and brown.

Step 4: Install 2pcs 1Kohm Metal Film Resistor

Install two 1K ohm metal film resistors at PCB locations R9 and R10. The color bands are brown, black, black, brown, and brown. Note: The screen printing indicating 510ohm on the PCB should be ignored for these resistors.

Step 5: Install 2pcs 10Kohm Metal Film Resistor

Install two 10K ohm metal film resistors at PCB locations R1 and R25. The color bands are brown, black, black, red, and brown.

Step 6: Install 2pcs 200ohm Metal Film Resistor

Install two 200 ohm metal film resistors at PCB locations R15 and R16. The color bands are red, black, black, black, and brown.

Step 7: Install 1pcs 2Kohm Metal Film Resistor

Install one 2K ohm metal film resistor at PCB location R28. The color bands are red, black, black, brown, and brown.

Step 8: Install 1pcs 1Mohm Metal Film Resistor

Install one 1Mohm metal film resistor at PCB location R3. The color bands are brown, black, black, yellow, and brown.

Step 9: Install 2pcs DO-35 1N4148 Diode

Install two DO-35 1N4148 diodes at PCB locations D1 and D22. Pay close attention to the installation direction. The 1N4148 diode has a black mark, and the PCB has a white mark to indicate the correct orientation.

Step 10: Install 4pcs DIP-8 IC Socket

Install four DIP-8 IC sockets at PCB locations U1, U2, U3, and U4. Each IC socket has a mark (notch) on one end, and the PCB has a corresponding curved silk screen printing mark. Align these marks to ensure the correct direction for IC placement.

Step 11: Determine LED Polarity

It is crucial to install LEDs correctly to ensure proper function. Several methods can be used to identify the positive (anode) and negative (cathode) leads:

• Lead Length: The positive (anode) lead is typically longer than the negative (cathode) lead.
• Plastic Case Inspection: The negative (cathode) lead may appear thicker or bigger inside the plastic case compared to the anode lead.
• Edge Observation: The negative (cathode) lead is often closest to the flat edge on the plastic case.
• Testing: A 3V battery or multimeter can be used. The pin connected to the positive terminal of a 3V power supply is the anode if the LED lights up. Caution: do not power for longer than 0.5 seconds.
• PCB Markings: The positive (anode) lead is indicated by a white '+' mark on the PCB.

The accompanying diagrams illustrate these methods: one shows a shorter pin labeled 'Negative Cathode' and a longer pin labeled 'positive pole'; another shows a flat edge on the plastic case indicating the 'Negative (cathode)' side, and a thicker/bigger metal part inside also indicating the 'Negative (cathode)' side.

Step 12: Bend LED Pins

Bend the pins of each LED to a 90-degree angle, paying attention to the bending point and direction to ensure proper functionality.

Step 13: Install 4pcs 5mm Pink LED

Install four 5mm pink LEDs at PCB locations D2, D3, D4, and D5. Ensure correct polarity as determined in Step 11.

Step 14: Install 4pcs 5mm Blue LED

Install four 5mm blue LEDs at PCB locations D6, D7, D8, and D9. Ensure correct polarity.

Step 15: Install 4pcs 5mm Green LED

Install four 5mm green LEDs at PCB locations D10, D11, D12, and D13. Ensure correct polarity.

Step 16: Install 1pcs 4.7uF Electrolytic Capacitor

Install one 4.7uF electrolytic capacitor at PCB location C4. The PCB silk screen printing features a white marking indicating where the negative (cathode) lead should be inserted. The shorter lead is the negative pole. The capacitor must be placed horizontally.

Step 17: Install 1pcs 100uF Electrolytic Capacitor

Install one 100uF electrolytic capacitor at PCB location C2. The PCB silk screen printing features a white marking indicating where the negative (cathode) lead should be inserted. The shorter lead is the negative pole. The capacitor must be placed horizontally.

Step 18: Install 2pcs 0.1uF 104 Monolithic Capacitor

Install two 0.1uF 104 monolithic capacitors at PCB locations C1 and C3.

Step 19: Install 1pcs 9.7mm MIC Microphone

Install one 9.7mm microphone at the MIC location. Pay attention to the marked pin, which indicates the negative pole, to differentiate between positive and negative poles.

Step 20: Install 1pcs 1Mohm Potentiometer

Install one 1Mohm potentiometer at the RP location. Note: This component needs to be installed on the other side of the PCB.

Step 21: Install 4pcs DIP-8 LM358 Amplifier

Install four DIP-8 LM358 amplifiers at PCB locations U1, U2, U3, and U4. Look for a gap mark on one end of the IC and a corresponding gap mark on the DIP-8 IC Socket. Align these marks to indicate the correct installation direction of the IC.

Step 22: Install 1pcs PH2.0-2P Wire

Install one PH2.0-2P wire at the CZ location on the back of the PCB. Connect the red wire to the '+' pad and the black wire to the '-' pad. Incorrect connection may damage the LED spectrum board.

Step 23: Connect PH2.0-2P Wire to 4ohm 3W Speaker

Connect the PH2.0-2P wire to the 4ohm 3W speaker. Ensure the red wire connects to the '+' pad of the speaker.

Step 24: Prepare Acrylic Boards

Carefully tear off the protective film from the surface of the acrylic boards.

Step 25: Mount DC-005 Power Socket

Fix one DC-005 power socket onto an acrylic board using its nut.

Step 26: Mount Red/Black Switch

Fix one Red/Black switch onto an acrylic panel. Ensure the switch's buckle is properly engaged. Pay attention to the correct installation direction.

Step 27: Connect Power Socket and Switch

Cut approximately 3cm of red wire. Connect this wire between the DC-005 power socket and the Red/Black switch. Ensure correct pin selection for the connection.

Step 28: Connect Wire to DC-005 and Switch

Connect one 10cm PH2.0-2P wire to the DC-005 power socket and the Red/Black switch. The red wire connects to the switch, and the black wire connects to the DC-005 power socket. Refer to wiring diagrams if wire colors differ.

Step 29: Install FM Antenna

Crimp about 3cm of wire to serve as the FM antenna and install it onto the Bluetooth receiver's designated pad.

Step 30: Mount Bluetooth Receiver

Fix the Bluetooth receiver onto an acrylic board using two M3*6mm screws and two M3 nuts.

Step 31: Connect LED Board to Bluetooth Receiver

Cut the PH2.0-2P plug from the LED board. Connect the red and black wires to the Bluetooth receiver's '5V' and 'GND' terminals, respectively. Note: The red wire connects to the '5V' pad, originating from the 'IN+' pad.

Step 32: Secure LED Board with Copper Pillars

Fix two M3*5+6mm copper pillar screws onto the LED board using two M3 nuts.

Step 33: Mount LED Spectrum Board

Mount the LED spectrum board onto another acrylic board using two M3*5mm screws.

Step 34: Mount 4ohm 3W Speaker

Fix one 4ohm 3W speaker onto an acrylic board using four M3*6mm screws and four M3 nuts. Ensure screws are installed in the correct direction.

Step 35: Mount First 4ohm 3W Speaker to LED Board

Mount one 4ohm 3W speaker onto the LED acrylic board using two M2*10mm screws and two M2 nuts.

Step 36: Mount Second 4ohm 3W Speaker to LED Board

Mount the second 4ohm 3W speaker onto the LED acrylic board using two M2*10mm screws and two M2 nuts.

Step 37: Mount Bluetooth Receiver to LED Board

Fix the Bluetooth receiver onto the LED acrylic board using two M2*10mm screws and two M2 nuts. Ensure the mounting holes of the LED board and acrylic align correctly.

Step 38: Connect Speakers to Bluetooth Receiver

Connect the two speaker wire plugs to the white sockets on the Bluetooth receiver.

Step 39: Install Acrylic Board with Switch

Install another acrylic board with the switch using two M2*10mm screws and two M2 nuts. Do not tighten these screws too tightly at this stage.

Step 40: Connect Switch to Bluetooth Receiver

Connect the PH2.0-2P plug from the Red/Black switch to the red socket on the Bluetooth receiver. NOTE: Ensure no other wires are near the FM antenna to avoid signal interference.

Step 41: Fix Top Acrylic Board

Fix the top acrylic board using four M2*10mm screws and four M2 nuts. Secure the screws previously left loose in Step 39.