Hw-044 Datasheet ((hot)) -

is a compact RS232 to TTL converter module commonly used to bridge communication between microcontrollers (like Arduino, ESP32, or Raspberry Pi) and legacy industrial or computer equipment using the RS232 standard. Arduino Forum

Below is a blog-style overview of the HW-044 datasheet specifications, pinout, and common use cases.

Bridging the Gap: A Guide to the HW-044 RS232-to-TTL Converter

In the world of DIY electronics, we often need to talk to "old school" hardware—things like old GPS units, POS systems, or industrial PLCs. These devices usually communicate over

, which uses voltage levels (±12V) that would instantly fry a modern 3.3V or 5V microcontroller. diyables.io That’s where the HW-044 module Key Specifications Based on the

integrated circuit, this module is highly efficient and operates at much lower voltages than older MAX232 variants. Operating Voltage:

3.3V to 5V DC (making it compatible with both Arduino and ESP32). Interface Type: RS232 Side: DB9 Female connector. 4-pin header. Data Rate: Up to 250 kbps. Communication: Full-duplex bidirectional serial. HW-044 Pinout Diagram The module is divided into two distinct sides: 1. The TTL Side (Microcontroller Connection) This is where you connect your Arduino or ESP32: Arduino Forum Power Supply (3.3V or 5V). TTL Serial Transmit (Connect to MCU RX). TTL Serial Receive (Connect to MCU TX). 2. The RS232 Side (External Device Connection) A standard DB9 Female connector for plugging in your RS232 cables. diyables.io Common Applications Industrial Interfacing: Connecting to PLCs or CNC machines. Legacy Hardware: Reviving old serial modems or printers. Debugging: Accessing serial consoles on networking gear. diyables.io Some versions of the HW-044 may be wired as rather than hw-044 datasheet

by mistake. If your communication isn't working, try swapping the lines on your DB9 connector. Arduino Forum wiring diagram for connecting this to an ESP32? ESP32 RS232 Communication - Programming - Arduino Forum 23 Jun 2025 —

The HW-044 Pinout (Critical for Wiring)

Looking at the 3-pin header on the board:

| Pin | Label | Function | | :--- | :--- | :--- | | 1 | SIG | Digital Output (HIGH when touched, LOW when idle) | | 2 | VCC | Power Supply (3.3V or 5V) | | 3 | GND | Ground |

Important Note: Some clone boards swap the order. Always check the silkscreen. If you wire 5V to SIG, you will destroy your microcontroller.

11. Where to Buy / Datasheet Availability

The HW-044 is sold on:

Note: There is no official single datasheet from one manufacturer, because HW-044 is a generic module name. However, the underlying circuit is well-documented using BSS138 level shifter schematics (e.g., from SparkFun or Adafruit’s 8-channel BSS138 breakout). is a compact RS232 to TTL converter module

3. Pinout Description (5-pin interface)

| Pin Name | Function | |----------|--------------------------------------------| | VCC | 5V power supply input. | | GND | Ground. | | DIN | Serial Data Input (MOSI from master). | | CS | Chip Select / LOAD (latches data into registers). | | CLK | Serial Clock (up to 10 MHz typical). |

Note: Some variants label CS as LOAD or CS.

Typical Price: $2 – $5 USD.

Common Aliases / Variants:

Warning: Counterfeit MAX98357 chips exist on very cheap boards. They may show lower output power, noise, or shut down at high temperatures. Buy from reputable sellers.

Limitations and design trade-offs

General Contents of a Datasheet

  1. Overview: A brief introduction to the component or module, including its function, application areas, and possibly its features.

  2. Specifications: Detailed technical specifications such as voltage ratings, current ratings, power consumption, operating temperature range, and physical dimensions. The HW-044 Pinout (Critical for Wiring) Looking at

  3. Pinout and Connections: For modules or components with multiple connections, a datasheet would typically include a pinout diagram or table, detailing what each pin or connection is used for.

  4. Electrical Characteristics: This section would provide graphs and tables detailing the electrical behavior of the component under various conditions, such as voltage versus current, frequency response, or impedance.

  5. Performance Graphs and Curves: These help in understanding how the component performs under different conditions. For example, a graph showing how the voltage output of a regulator changes with input voltage or load current.

  6. Application Information: Sometimes, datasheets include application notes or examples of how the component can be used in a circuit, along with recommended external components.

  7. Packaging and Environmental Information: Details on how the component is packaged, its weight, and information on its environmental compliance, such as RoHS (Restriction of Hazardous Substances) status.

  8. Reliability and Testing Information: Data on the component's reliability, including MTBF (Mean Time Between Failures) estimates, and any relevant testing standards.

Electrical characteristics (typical assumptions)