NE555 adjustable duty cycle pulse frequency square wave signal generator module for experimental development and MCU timing Key benefits Flexible timing source: adjustable duty cycle and frequency to suit a wide range of MCU projects and circuit testing. Simple power options: operates from a 5 to 15 V DC supply, making it compatible with common development boards and test rigs. Manageable drive capability: provides measurable output current for small signal applications and control circuits. What you get Input voltage: 515 V DC Input current: greater than 100 mA Output current: 15 mA at 5 V, 35 mA at 12 V Indicator Output LED indicator is activelow: the LED lights when the signal is low and turns off when the signal is . LED flashing behavior corresponds to the square wave frequency (lower frequencies result in slower LED flashes). Controls and configuration Four jumpers and two variable resistors allow straightforward adjustment of the output waveform to achieve the desired duty cycle and frequency. Use scenarios Prototyping and development for microcontroller projects: generate a reliable timing signal to test peripherals, timers, and interfaces. Lab testing and circuit characterization: provide a controllable square wave to evaluate filters, comparators, ADC sampling, or other timingsensitive circuitry. Debugging and signal generation: use as a compact, adjustable source for bench experiments when a precise timing reference is needed. Notes The description, specifications, model, and functions are aligned with the NE555 based signal generator while avoiding additional or omit details.