WT2003HB01 Voice Module
Compact UART‑Controlled Voice Playback Module with Built‑in 0.5W Amplifier
The WT2003HB01 is a compact, high‑performance voice module based on the WT2003HX chip. Powered by a 32‑bit processor up to 120MHz, it supports SPI‑Flash and USB drive storage for flexible audio content management. With 32‑level volume control, a built‑in 0.5W Class‑D amplifier, and a simple UART command set (default 9600 baud), it is ideal for quick integration into voice prompt systems, home appliances, toys, and industrial equipment.
- 32‑bit processor – 120MHz for smooth playback
- UART control – simple serial commands
- SPI‑Flash & USB – flexible storage options
- Built‑in 0.5W amp – direct speaker drive
- 32‑level volume – with power‑off memory
Key Features
UART Command Set
| Command | Function | Description |
|---|---|---|
| A0 | Flash Index Playback | Play audio by index in SPI-Flash root directory |
| A1 | Flash Filename Playback | Play audio by filename in SPI-Flash root (4-byte name) |
| A6 | USB Index Playback | Play audio by index in USB drive root |
| A7 | USB Filename Playback | Play audio by filename in USB drive root (4-byte name) |
| A8 | USB Folder Index Playback | Play audio by index in USB folder (5-char folder name) |
| A9 | USB Folder Filename Playback | Play audio by filename in USB folder |
| AA | Pause / Resume | Toggle pause/playback |
| AB | Stop | Stop current playback |
| AC | Next Track | Play next track |
| AD | Previous Track | Play previous track |
| AE | Volume Control | Set volume (0–31, with power‑off memory) |
| AF | Playback Mode | Normal / Single loop / All loop / Random |
| B1 | Insert Playback | Insert a track during current playback |
| B6 | Output Mode Switch | Switch between PWM (SPK) and DAC |
| C1 | Query Volume | Read current volume level |
| C2 | Query Work Status | Play / Stop / Pause |
| C3 | Query Flash File Count | Get total audio files in SPI-Flash |
| C7 | Query USB File Count | Get total audio files in USB drive |
| C8 | Query USB Folder File Count | Get audio file count in USB folder |
| C9 | Query Current Track | Get current playback track address |
| CA | Query Peripheral Status | Check Flash and USB connection status |
| CB | Query Current Song Name | Get filename of current playback |
Protocol format: 7E + Length + Command + Parameters + Checksum + EF. Checksum is the low byte of (Length + Command + Parameters) sum.
Technical Specifications
| Parameter | Value / Condition |
|---|---|
| Processor | 32‑bit, up to 120MHz |
| Operating Voltage | 2.4V – 5.2V |
| Audio Formats | MP3, WAV (8–320kbps) |
| Storage Media | SPI‑Flash (128Mbit), USB drive (32GB, FAT/FAT32) |
| Audio Output | PWM (0.5W Class‑D) / DAC |
| Volume Levels | 32 (0–31, with power‑off memory) |
| Playback Modes | Normal, Single loop, All loop, Random |
| Control Interface | UART (default 9600 baud) |
| Peripherals | I2C, PWM, Infrared decoder, 16‑bit ADC/DAC |
| IO Drive Capability | Up to 64mA |
| Operating Temperature | ‑40°C ~ +85°C |
| Module Size | 21.21 × 18.24 × 3.35mm (±0.3mm) |
| Pin Pitch | 2.0mm |
Key Pin Functions (20‑Pin Module)
| Pin | Name | Function |
|---|---|---|
| 2 | SPIDAT | SPI‑Flash data |
| 3 | SPK+ | Speaker positive terminal |
| 4 | SPK− | Speaker negative terminal |
| 5 | DACR | DAC right channel output |
| 6 | DACL | DAC left channel output |
| 8 | AGND | Analog ground |
| 9 | MIC | Microphone input |
| 11 | BUSY | Busy signal output (high during playback) |
| 12 | TXD | UART transmit |
| 13 | RXD | UART receive |
| 14 | SPICLK | SPI‑Flash clock |
| 15 | PWRKEY | ADC channel |
| 16 | VDD33 | 3.3V power output |
| 17 | SPICS | SPI‑Flash chip select |
| 18 | VDD | Power input (2.4–5.2V) |
| 19 | DM | USB D− |
| 20 | DP | USB D+ |
Application Scenarios
Why Choose WT2003HB01
Frequently Asked Questions
What is the WT2003HB01 voice module?
WT2003HB01 is a compact voice playback module based on the WT2003HX chip, featuring a 32-bit processor (up to 120MHz), UART serial control, SPI-Flash and USB storage, built-in 0.5W amplifier, and 32-level volume control.
How do I control the module?
The WT2003HB01 module uses a standard UART serial interface with default baud rate 9600. Commands follow a 7E … EF protocol for playback, volume, mode, and query operations.
What storage media are supported?
WT2003HB01 supports SPI-Flash (up to 128Mbit) and USB drives (up to 32GB, FAT/FAT32 format). The Flash can be accessed as a virtual USB drive when connected to a PC.
What audio formats are supported?
WT2003HB01 supports MP3 and WAV formats with bitrates from 8kbps to 320kbps, delivering high-quality audio playback.
Does it have a built-in amplifier?
Yes. It features a built-in 0.5W Class-D amplifier with PWM output. DAC output is also available with a command switch (B6).
How many volume levels are available?
32 levels (0 to 31), with 0 = mute and 31 = maximum volume. The setting has power-off memory.
What is the operating voltage range?
The module operates from 2.4V to 5.2V, compatible with both 3.3V and 5V systems.
Can I update audio files via USB?
Yes. Connect the module to a PC via USB, and the Flash storage appears as a removable drive. Copy audio files directly, then disconnect USB before sending serial commands.
What are the module dimensions?
The module measures 21.21mm × 18.24mm × 3.35mm (±0.3mm) with 2.0mm pin spacing, making it suitable for compact designs.
What are the typical applications?
Voice prompt systems, home appliances, automotive electronics, toys, industrial alarms, consumer electronics, and any application requiring simple voice playback with flexible storage.
Important: For external Flash, Waytronic‑branded Flash is recommended for guaranteed compatibility. The module supports FAT and FAT32 formats only. After copying audio files via USB, disconnect the USB cable before sending UART commands. The BUSY pin is low in idle and high during playback. When switching audio output modes (B6), wait 200ms before sending other commands.
