Sound to Light Color Shield for OLEDUINO v2

This project is a Sound-to-Light Color Shield designed for the OLEDUINO-V2. The shield includes a low-voltage microphone preamplifier and a rectifier circuit that converts the AC audio signal into a DC voltage. This DC signal is fed to the analog input pin (A1) of the OLEDUINO-V2.

When the microphone receives sound, the preamplifier generates small DC pulses corresponding to the audio signal. The OLEDUINO-V2 microcontroller reads this signal through its ADC and processes it to control a NeoPixel digital RGB LED strip.

A 3-pin header is provided on the board for easy connection of the LED strip. Users can develop their own code to create various effects such as:

• Sound-to-color conversion
• Sound-activated ON/OFF control
• Sound-based lighting patterns and animations

This is a fun and versatile project that can be used in many creative applications.

D1 and C6 convert the AC audio signal into a DC voltage, which is measured by the Arduino’s ADC. The user can adjust the RC filter values according to the application requirements.

Features

• 5V DC supply
• 3-pin header connector for LED interface
• Compact size
• PCB dimensions: 25.4 mm × 25.4 mm

Microphone Amplifier

Electret microphones are commonly used in portable electronics because of their small size, low cost, and relatively good signal-to-noise ratio (SNR). The small package size, low operating voltage and excellent AC performance of the TLV6741 make it an excellent choice for preamplifier circuits for electret microphones. The circuit shown in Figure is a single-supply preamplifier circuit for electret microphones, consist the TLV6741 device. TLV6741 10Mhz, low broadband noise, pro, operational amplifier

This project uses an op amp in a transimpedance amplifier configuration to convert the output from an electret microphone in to an output voltage. The common voltage of this circuit is constant and set to mid-supply eliminating any input-stage cross over distortion. Diode and capacitor on output converts audio AC signal in to DC signal.

OLEDUINO-V2

https://www.electronics-lab.com/project/oleduino-v-2/

Arduino Code

Arduino Code provided to test the board, user may modify and write own code to create light to RGB light effect

More Information on Neo Pixel LED: https://www.adafruit.com/product/1138

Connections

• CN1: No Use
• CN2: NeoPixel LED, Pin 1 = VCC/5V DC, Pin 2 = Data, Pin 3 = GND
• Arduino Pins: D9 Digital Pin = NeoPixel Data Pin, Analog A1 = Audio Signal Input

Schematic

Parts List

Connections

Gerber View

Photos

TLV6741 Datasheet