Howtosignalprocessing
- How to output PWM from Arduino?
- How to convert PWM output to analog signal?
- How to calculate PWM duty cycle in Arduino?
How to output PWM from Arduino?
On an Arduino Uno, PWM output is possible on digital I/O pins 3, 5, 6, 9, 10 and 11. On these pins the analogWrite function is used to set the duty cycle of a PWM pulse train that operates at approximately 500 Hz2. Thus, with a frequency fc = 500Hz, the period is τc = 1/fc ∼ 2ms.
How to convert PWM output to analog signal?
PWM signals can be transformed into analog signals using a simple RC type low-pass filter. The PWM duty cycle determines the magnitude of the filter's voltage output. As the duty cycle increases, the average voltage output increases, and vice versa.
How to calculate PWM duty cycle in Arduino?
Duty Cycle = (Ton/(Ton+Toff))*100;
I put PulseIn function to get the number of microseconds needed to complete ON and OFF period separately. Then add ON and OFF and take F = 1/T formula to get the frequency. That's all!
