WT2003HM04 Voice Module
Multi‑Mode Voice Module with UART, 1‑Wire & 2‑Wire Control, 900s Built‑in Voice
The WT2003HM04 is a highly versatile voice module offering UART, 1‑wire, and 2‑wire serial control options to suit various system architectures. Powered by a 32‑bit processor up to 120MHz, it features 900 seconds of built‑in voice storage and supports external SPI‑Flash up to 128Mbit. With 32‑level (UART) or 8‑level (1/2‑wire) volume control, a built‑in 0.5W Class‑D amplifier, and USB mass storage emulation, it is ideal for voice prompt systems, appliances, and industrial equipment.
- 32‑bit processor – 120MHz for smooth playback
- 3 control modes – UART, 1‑wire, 2‑wire (selectable)
- 900s built‑in voice – plus SPI‑Flash expansion
- Built‑in 0.5W amp – direct speaker drive
- Volume control – 32 or 8 levels with memory
Function Code Selection
| Function Code | Communication Protocol | Default Output | Storage |
|---|---|---|---|
| A04 | UART | PWM (DAC via command) | Built‑in + SPI‑Flash |
| A05 | 1‑wire (single‑byte) | ||
| A07 | 2‑wire (single‑byte) | ||
| A15 | 1‑wire (double‑byte) | ||
| A17 | 2‑wire (double‑byte) |
The control mode is fixed during programming and must be specified when ordering. Contact Waytronic sales for custom requirements.
Key Features
Technical Specifications
| Parameter | Value / Condition |
|---|---|
| Processor | 32‑bit, up to 120MHz |
| Operating Voltage | 2.6V – 5.0V (ripple <5%, peak <5.5V) |
| Built‑in Voice Storage | 900 seconds |
| External SPI‑Flash | Up to 128Mbit (FAT/FAT32) |
| Audio Formats | MP3, WAV (8–320kbps) |
| Audio Output | PWM (0.5W Class‑D) / DAC |
| Volume Levels | UART: 32 (0–31), 1/2‑wire: 8 (E0–E7) |
| Playback Modes | Normal, Single loop, All loop, Random, Combo, Insert |
| Control Interfaces | UART (9600 baud), 1‑wire, 2‑wire |
| Deep Sleep Current | < 3 µA |
| Standby Sleep Current | < 30 µA |
| IO Drive Capability | Up to 64mA |
| Operating Temperature | ‑40°C ~ +85°C |
| Module Size | 21.01 × 18.21mm |
| Pin Pitch | 2.0mm |
UART Command Highlights
| Command | Function | Description |
|---|---|---|
| A0 | Index Playback | Play by index in Flash |
| A1 | Filename Playback | Play by 4‑byte filename |
| AA | Pause / Resume | Toggle pause |
| AB | Stop | Stop playback |
| AC/AD | Next / Previous | Track navigation |
| AE | Volume | Set 0–31 |
| AF | Playback Mode | Normal / Loop / All‑loop / Random |
| B0 | Combo Playback | Play up to 20 tracks in sequence |
| B1 | Insert Playback | Insert a track during playback |
| B6 | Output Switch | PWM ↔ DAC |
| B8 | Low Power | Deep sleep (00) or standby (01) |
| C0–C3 | Queries | Version, volume, status, file count |
| C9 | Current Track | Get playing address |
1‑Wire & 2‑Wire Command Highlights
| Command | Function | Description |
|---|---|---|
| 00H–DFH | Play Address | Play corresponding voice segment (224 addresses) |
| E0H–E7H | Volume Control | E0 min, E7 max (8 levels) |
| F0 | Auto Sleep | Enter sleep after playback |
| F1 | Exit Auto Sleep | Stay in standby |
| F2 | Loop Playback | Loop current segment |
| F3 | Chain Playback | Play multiple addresses sequentially (max 10 segments) |
| F4 00/01 | Output Switch | DAC (00) / PWM (01) |
| F4 02/03 | Sleep Mode | Deep (02) / Standby (03) |
| FE | Stop | Stop playback |
Key Pin Functions (20‑Pin Module)
| Pin | Name | Function |
|---|---|---|
| 2 | VCC | Power input (2.6–5.0V) |
| 3 | TXD | UART transmit |
| 4 | RXD | UART receive |
| 5 | BUSY | Busy signal (high during playback) |
| 6 | ADKEY | Analog key input |
| 7 | SPK+ | Speaker positive |
| 8 | SPK− | Speaker negative |
| 9 | DACR | DAC right channel |
| 10 | DACL | DAC left channel |
| 11 | DM | USB D− |
| 12 | DP | USB D+ |
| 13 | SDDAT | SD card data |
| 14 | SDCMD | SD card chip select |
| 15 | SDCLK | SD card clock |
| 16 | VOUT | 3.3V output |
| 19 | AGND | Analog ground |
| 20 | MIC | Microphone input |
Application Scenarios
Why Choose WT2003HM04
Frequently Asked Questions
What control modes does WT2003HM04 support?
WT2003HM04 supports UART, 1-wire serial, and 2-wire serial control modes. The specific mode is fixed during programming and must be selected when ordering using the function code (A04 for UART, A05 for 1-wire single-byte, A07 for 2-wire single-byte, A15 for 1-wire double-byte, A17 for 2-wire double-byte).
What is the built-in voice storage capacity?
The WT2003HM04 module has 900 seconds of built-in voice storage. It also supports external SPI-Flash expansion up to 128Mbit for additional voice content.
Does it have a built-in amplifier?
Yes. WT2003HM04 features a built-in 0.5W Class-D amplifier with PWM output. DAC output is also available with a command switch (B6 for UART or F4 00 for 1-wire/2-wire).
How many volume levels are available?
For UART mode, 32 levels (0–31). For 1-wire and 2-wire modes, 8 levels (E0–E7). Volume settings have power-off memory.
What is the operating voltage range?
The WT2003HM04 module operates from 2.6V to 5.0V, with ripple controlled within 5% and peak voltage below 5.5V.
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 is the module size?
The module measures 21.01mm × 18.21mm with 2.0mm pin spacing.
What audio formats are supported?
It supports MP3 and WAV formats with bitrates from 8kbps to 320kbps.
What is the power consumption in sleep mode?
Deep sleep consumes less than 3µA, while standby sleep consumes less than 30µA. The default is deep sleep mode.
What are the typical applications?
Voice prompt systems, home appliances, automotive electronics, toys, industrial alarms, consumer electronics, and any application requiring flexible control interface options.
Important: The control mode is fixed during programming – specify the function code when ordering. For external SPI‑Flash, Waytronic‑branded Flash is recommended for guaranteed compatibility. After copying audio files via USB, disconnect the USB cable before sending serial commands. The BUSY pin is low in idle and high during playback. In deep sleep mode, wake the chip with a 0xFE command and wait 100ms before sending other commands. The default output is PWM – use the appropriate command to switch to DAC.
