Hw-044 Datasheet

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

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 —

What Exactly is the HW-044?

The HW-044 is a digital touch sensor module based on the TTP223 capacitive touch sensor IC. Unlike a physical push-button that requires mechanical force, the HW-044 detects the change in capacitance when a finger (or conductive object) approaches the pad.

Common Aliases: Keyestudio Touch Sensor, TTP223 Module, Capacitive Touch Switch.

Wiring Diagram

| HW-044 Pin | Arduino Uno Pin | | :--- | :--- | | GND | GND | | + (VCC) | 5V | | SW | Pin 4 | | DT | Pin 3 | | CLK | Pin 2 |

Example host initialization (pseudocode)

i2c_write_reg(0x01, 0x0A)  // set sampling rate, enable averaging
i2c_write_reg(0x06, HIGH_TH_MSB)
i2c_write_reg(0x07, HIGH_TH_LSB)
poll STATUS until DRDY=1
value = i2c_read_words(0x02, 2)  // read measurement MSB/LSB