This 2-channel PWM pulse / square wave generator provides two pulse / square wave outputs with independent control over each channel's duty cycle and frequency using the LED display and set/up/down buttons. It can also be programmed through its serial RS-232 interface.
Applications include:
A square wave generator to generate square wave signals for experimentation and control
Driving stepper motors
Generating adjustable pulses for microcontroller use
Generating adjustable pulses for PWM control of lighting and LEDs

Features and Specifications:
Operating Voltage: 5-30V, supports MicroUSB 5V input power
Frequency Range: 1Hz - 150KHz
Frequency Precision: 2%
Output Signal Capacity: Up to 30mA output current
Output Voltage: Same as input voltage, or can be independently varied from 5V to 30V with an external power supply input
Ambient Operating Temperature: -30C to 70C
Bboard dimensions: 4.3x2.9x0.9cm (1.69x1.14x0.35inches)
The 4 mounting holes are 2mm through-holes, inset 2mm from each corner of the board

Operating Parameter Settings:
The module has 3 control buttons: Set, Up, and Down
Short pressing the SET key will step the display through the 4 operating parameter values:
FR1: PWM1 frequency
dU1: PWM1 duty cycle
FR2: PWM2 frequency
dU2: PWM2 duty cycle
Duty cycle can be set from 1% to 100% in 1% increments.
Package Includes:
1X 2-Channel 5V PWM Pulse Square Wave Generator Module
Link to online installation and operation instructions