Hw-044 Datasheet ((hot))

For typical Arduino connections, connect the Arduino RX pin to the module's RXD pin

mm) makes it easy to integrate into DIY projects or equipment upgrades.

Note: Pins 1, 4, 6, 7, 8, and 9 are structurally present but typically unrouted/tied together internally on basic HW-044 modules, as hardware flow control (RTS/CTS) is bypassed in favor of simple three-wire communication. Functional Block & Schematic Breakdown hw-044 datasheet

The is a highly popular, low-cost RS232 to TTL serial converter board designed to bridge the communication gap between legacy industrial machinery and modern microcontrollers . Powered by the robust MAX3232 transceiver IC , this module effortlessly converts high-voltage RS232 signals (up to ±15V) into safe, low-voltage TTL signals (3.0V to 5.5V) compatible with platforms like Arduino, ESP32, STM32, and Raspberry Pi.

The HW-044 requires a standard I²S (Philips) format. Do not use DSP, TDM, or Right-Justified modes unless you can reconfigure the chip via I²C (not available on HW-044 — it’s hardwired).

Connecting this module is straightforward. Here's how to set it up with an Arduino Uno: | Jumper Setting | Mode | Behavior |

: Operates efficiently on a power supply between 3.3V and 5.5V , making it compatible with both 3.3V logic (ESP32, STM32) and 5V logic (Arduino Uno).

| Symptom | Likely Cause | Solution | |---------|--------------|----------| | No sound, PWR LED off | No power or reversed VIN/GND | Check voltage at VIN pin. Reverse polarity kills the IC. | | Humming or high noise | Shared ground with high-current devices | Create a star ground. Separate digital and power grounds. | | Distorted audio at high volume | Clipping due to high gain | Reduce GAIN setting (float or GND). Lower source volume. | | Clicking or popping | Sample rate mismatch or BCLK unstable | Ensure I²S clock is continuous. Use internal PLL if available. | | Only left or right channel missing | Mono mode enabled (normal) | HW-044 is mono. Combine channels in software. | | Amplifier gets very hot | Speaker impedance too low (<4Ω) or short circuit | Use 4Ω–8Ω speaker. Check SPK+ to SPK- resistance. | | No sound with ESP32 | Wrong I²S pins or format | Confirm BCLK/LRC/DIN assignments. Use i2s_std driver. |

The HW-044 has clearly labeled on the PCB: Touch again: Output goes LOW

Connecting an RS232 line directly to a 3.3V or 5V microcontroller pin will cause instant, permanent damage to the chip. The HW-044 module uses its integrated to safely step down the high RS232 voltages to safe TTL pulses, and invert/boost microcontroller outputs back to full RS232 specifications. Pinout Configuration

The is a compact, high-speed RS232 to TTL converter module designed to bridge the communication gap between legacy serial equipment and modern microcontrollers like Arduino, ESP32, and Raspberry Pi.

# Enable I2S dtoverlay=max98357a

To summarize:

| Symptom | Likely Fix | |---------|-------------| | No signal on output | Check both LV and HV power are present and grounds connected | | Signal stuck high/low | Ensure both sides have common ground; check if signal is open-drain | | I²C not working | Reduce bus speed; check pull-up resistor values (4.7kΩ is fine for most) | | Distorted waveform at high speed | Reduce communication speed; use shorter wires |