WT2003HB02 Voice Module
Compact UART‑Controlled Voice Playback Module with TF Card & USB Storage, Built‑in 0.5W Amp
The WT2003HB02 is a compact, high‑performance voice module based on the WT2003HX chip. Powered by a 32‑bit processor up to 120MHz, it supports TF card (microSD) 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
- TF card & 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 |
|---|---|---|
| A2 | TF Card Index Playback | Play audio by index in TF card root directory |
| A3 | TF Card Filename Playback | Play audio by filename in TF card root (4-byte name) |
| A4 | TF Card Folder Index Playback | Play audio by index in TF card folder (5-char folder 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 |
| C5 | Query TF Card File Count | Get total audio files in TF card |
| C6 | Query TF Card Folder File Count | Get audio file count in TF card folder |
| 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 TF card, USB, and PC 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 | TF card (32GB, FAT/FAT32), 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 | SD_CMD | SD card chip select |
| 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 | ONEKEY | Next track button |
| 11 | MP3_EN | Busy signal output |
| 12 | TXD | UART transmit |
| 13 | RXD | UART receive |
| 14 | SDCLK | SD card clock |
| 15 | PWRKEY | Power key / ADC channel |
| 16 | VDDIO | 3.3V power output |
| 17 | SDDAT | SD card data |
| 18 | VBAT | Power input (2.4–5.2V) |
| 19 | DM | USB D− |
| 20 | DP | USB D+ |
Application Scenarios
Why Choose WT2003HB02
Frequently Asked Questions
What is the WT2003HB02 voice module?
WT2003HB02 is a compact voice playback module based on the WT2003HX chip, featuring a 32-bit processor (up to 120MHz), UART serial control, TF card and USB storage, built-in 0.5W amplifier, and 32-level volume control.
What storage media are supported?
WT2003HB02 supports TF card (microSD) up to 32GB and USB drives up to 32GB, both in FAT or FAT32 format. Both can be accessed as virtual drives when connected to a PC via USB.
What audio formats are supported?
WT2003HB02 supports MP3 and WAV formats with bitrates from 8kbps to 320kbps, delivering high-quality audio playback.
How do I control the module?
The WT2003HB02 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.
Does it have a built-in amplifier?
Yes. WT2003HB02 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 both TF card and Flash storage appear as removable drives. 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 TF card or USB storage.
Important: 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 (MP3_EN) is low in idle and high during playback. For external Flash, Waytronic‑branded Flash is recommended for guaranteed compatibility. When switching audio output modes (B6), wait 200ms before sending other commands.
