The VS1003 MP3 Onboard Microphone Module is a complete, cost-effective audio solution built around the VS1003B audio codec from VLSI Solution. It combines high-quality MP3/WMA/WAV/MIDI decoding with onboard voice recording capability, making it a versatile choice for embedded audio projects, voice playback systems, and interactive devices requiring both audio output and microphone input.
At the heart of the module is the VS1003B single-chip audio decoder and ADPCM encoder. It contains a high-performance, low-power VS_DSP4 processor core, working data memory, 5.5 KiB of on-chip RAM for user applications, serial control and data interfaces, and a high-quality variable-sample-rate mono ADC and stereo DAC followed by an earphone amplifier . The chip can decode MP3 (MPEG 1 & 2 audio layer III), WMA 4.0/4.1/7/8/9, WAV (PCM + IMA ADPCM), and General MIDI / SP-MIDI files, and supports streaming for MP3 and WAV .
The module includes an onboard microphone for voice recording, along with a line input for external audio sources . Recording uses the IMA ADPCM encoding format (mono), and the recorded audio can be saved directly to a file by the host microcontroller . The module also features a 3.5mm audio output jack capable of driving a 30-ohm load (earphones or small speakers), and supports bass and treble controls for audio adjustment .
Communication with the module is handled through the SPI bus, which internally connects to two separate interfaces: the SCI (Serial Control Interface) for register access and configuration, and the SDI (Serial Data Interface) for streaming audio data to the decoder . The DREQ (Data Request) pin indicates when the VS1003B is ready to receive more data, ensuring smooth audio streaming without buffer overruns .
The module operates from a 5V DC supply and includes onboard AMS1117 regulators providing 3.3V and 2.5V for the VS1003B’s analog, digital, and I/O power domains . A 12.288 MHz crystal provides the clock reference, and the chip includes an internal PLL clock multiplier . The module also includes a power indicator LED and exposes 4 general-purpose I/O pins (GPIO0–GPIO3) for additional customization .
Whether you are building a voice playback device, an MP3 player, a message recording system, or an interactive audio project, the VS1003 module provides a proven, well-documented foundation. It is suitable for individual makers, students, and businesses purchasing in bulk for product development or educational programs.
Features
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VS1003B audio codec — Single-chip MP3/WMA/WAV/MIDI decoder with ADPCM encoder
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Onboard microphone — For voice recording and voice playback applications
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Multiple audio formats — Decodes MP3, MP3+V, WMA, WAV, MIDI, and SP-MIDI
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Line input — For external audio sources alongside the onboard microphone
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IMA ADPCM recording — Mono voice recording with file-saving capability via host MCU
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Stereo DAC and earphone driver — High-quality 18-bit oversampling DAC capable of driving 30-ohm loads
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SPI interface — Separate SCI (control) and SDI (data) buses for flexible integration
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Onboard regulators — AMS1117 provides 3.3V and 2.5V from a single 5V supply
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4 GPIO pins — Available for custom application extensions
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Compact and cost-effective — Complete audio solution with low BOM cost
Technical Specifications
| # | Parameter | Specification |
|---|---|---|
| 1 | Audio Codec | VS1003B (VLSI Solution) |
| 2 | Decoding Formats | MP3, MP3+V, WMA, WAV, MIDI, SP-MIDI |
| 3 | Recording Format | IMA ADPCM (mono) |
| 4 | DAC Resolution | 18-bit oversampling |
| 5 | Supply Voltage | 5V DC (onboard regulators for 3.3V/2.5V) |
| 6 | Crystal Frequency | 12.288 MHz |
| 7 | Headphone Output | Stereo, drives 30Ω load |
| 8 | On-chip RAM | 5.5 KiB for user code/data |
