2-Channel 5V PWM Pulse / Square Wave Generator Module 1Hz-150KHz Frequency

📋 Overview

This economical 2-Channel 5V PWM Pulse / Square Wave Generator Module gives you two fully independent square wave outputs, each with its own adjustable frequency and duty cycle. A simple 3-button interface and 3-digit LED display make it easy to dial in exactly the signal you need — no computer or microcontroller required. When automation is needed, the built-in RS-232 serial interface lets you control both channels programmatically at 9600 baud.

With a frequency range spanning 1Hz to 150KHz and duty cycle adjustable from 1% to 100% in 1% steps, this module is equally at home on the workbench as a signal generator or built into a project as a permanent PWM source. Power it from any MicroUSB charger or supply up to 30V through the onboard pads.

Note: This module is produced by more than one manufacturer and may arrive with one of two firmware versions. Both versions cover the same frequency range and specifications — only the button operation steps differ. Complete instructions for both versions are provided in the User Guide.

⭐ Key Features

• Two fully independent PWM channels — set different frequencies and duty cycles on each
• Wide frequency range: 1Hz to 150KHz
• Adjustable duty cycle: 1% to 100% in 1% increments
• Intuitive 3-button control (SET, UP, DOWN) with 3-digit LED display
• RS-232 serial interface for computer or microcontroller control (9600 bps, 8N1)
• MicroUSB 5V power input — power from any USB charger or power bank
• Wide supply range: 5V to 30V via onboard pads
• Up to 30mA output current per channel
• Output voltage adjustable via external supply (requires one-time trace cut)
• Settings saved to memory — module powers up with last-used frequency and duty cycle
• Operating temperature: −30°C to 70°C

📦 What's in the Box

• 1× 2-Channel 5V PWM Pulse / Square Wave Generator Module

Note: Connecting wires are not included. Output signal connections require soldering directly to the pads on the board.

📊 Specifications

📌 Connections & Pinout

All signal and power connections are made via solder pads on the board. The MicroUSB port is the simplest way to power the module at 5V. VCC and GND pads allow an alternative DC supply from 5V to 30V.

🔧 Button Operation

The module has three buttons — SET, UP, and DOWN — and a 3-digit LED display. Short-pressing SET cycles through the four parameters: Channel 1 Frequency, Channel 1 Duty Cycle, Channel 2 Frequency, and Channel 2 Duty Cycle. Once a parameter is selected, UP and DOWN adjust its value.

Frequency is displayed and entered in one of three ranges, selected by pressing SET while in a frequency parameter. The display format indicates the active range:

Two firmware versions: The exact button sequence differs slightly between the two versions of firmware shipped with this module. The specifications and frequency range are identical. Full step-by-step instructions for both versions are in the User Guide — see the Documentation & Resources section below.

💻 RS-232 Serial Control

Both channels can be controlled via RS-232 serial commands. Connect a serial adapter or microcontroller UART to the module's serial pads at 9600 baud, 8N1, no flow control.

The module responds with DOWN on success and FALL if a command is not recognized or the value is out of range.

Logic Level Note: The serial interface operates at 5V logic. Use a logic level converter when connecting to 3.3V devices such as an ESP32 or Raspberry Pi.

🎯 Applications

• Stepper Motor Control: Supply step-pulse signals to A4988, DRV8825, or TMC2209 driver boards — adjust motor speed by changing output frequency
• LED and LED Strip Dimming: PWM-control brightness through a MOSFET driver stage
• Microcontroller Testing: Generate test signals for GPIO inputs during firmware development without writing any code
• Bench Signal Generator: Quick square wave source for timing circuits, relay testing, and frequency measurement verification
• Servo Motor Testing: Drive RC servos at 50Hz with variable duty cycle to test position control
• Automotive ECM Testing: Simulate RPM and vehicle speed sensor signals for bench diagnostics
• Educational Use: Demonstrate square wave generation, duty cycle, and PWM concepts in the classroom or workshop

⚠️ Important Notes

• Output signal connections require soldering — no plug-in terminals are provided for CH1, CH2, VCC, or GND pads
• Maximum output current is 30mA per channel. Use a MOSFET or transistor buffer for loads exceeding 30mA
• This module ships with one of two firmware versions; both have the same frequency range and output specifications, but button procedures differ slightly — the User Guide covers both
• Frequency precision is ±2%, suitable for PWM control and motor driving but not precision frequency reference applications
• Output voltage defaults to the supply voltage level. To use a different output voltage, an external supply must be connected to the back-side pads and the onboard trace cut — this modification is permanent
• Do not exceed 30V on either the supply input or the external output voltage pads

📄 Documentation & Resources

• User Guide — Button Operation, RS-232 Commands, Wiring & Troubleshooting
• All Logic & Timing Module User Guides

Sold and supported by Envistia Mall. Ships from the USA. For complete setup instructions, button operation procedures, RS-232 commands, and troubleshooting, visit the User Guide linked above. The manufacturer and Envistia LLC (dba Envistia Mall) are not responsible for any damages or losses resulting from the use of this product. Always follow proper electrical safety practices when working with electronic components. Specifications are based on manufacturer data and are subject to change without notice.