WTR-S4 voice recorder module adopts WTR recorder chip and SPI flash storage. It can record sound for a long time. And the longest recording time can be 2730 seconds. Compared with other recorder chips or circuits, it has the advantages of long single-chip recording time (no cascading), low cost and clear voice.
The WTR‑S4 is a voice‑recording module built around an 8‑bit DSP core, offering 16‑bit ADC input and 16‑bit DAC output. It supports external SPI‑Flash memory from 4 Mbit to 64 Mbit, selectable sampling rates from 6 kHz to 16 kHz, and operates from 2.7 V to 3.6 V.
Three control modes are available – button control, button‑one‑to‑one control and a three‑wire serial (SPI‑like) interface – each with dedicated pin functions and command sets. The manual details pin assignments, power consumption, wiring diagrams and example firmware for the serial mode. This manual is written in Chinese.
| ADC resolution | 16 bit |
|---|---|
| DAC resolution | 16 bit |
| Operating voltage range | DC 2.7 V – 3.6 V |
| Power consumption (recording) | 17.9 mA @ 3.3 V |
| Power consumption (sleep) | 120 µA @ 3.3 V |
| Supported SPI‑Flash capacity | 4 Mbit – 64 Mbit |
| Supported sampling rates | 6 kHz – 16 kHz |
| Maximum continuous recording time (6 kHz) | 2730 seconds |
It works from DC 2.7 V up to 3.6 V.
The module can store up to 255 recording segments.
It supports button control mode, button‑one‑to‑one control mode, and three‑wire serial control mode.
Sleep mode draws about 120 µA at 3.3 V.