What is the difference between the set_PWM_dutycycle function and the hardware_PWM function in the pigpio python library when assuming the same frequency is set for both the functions. Will I get a more stable output from one versus the other? I'm using the Pi 2 Model B and need 4 separate PWM signals with different outputs but same frequency.
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hardware_PWM >>> set_PWM_dutycycle >>> software PWM
where >>> is orders of magnitude better pulse stability.
- rock solid pulses
- large choice and range of frequencies
- large number of steps between off and fully on
- very stable pulses, unlikely to be affected by anything other than sustained heavy network traffic.
- 18 different frequencies (8000, 4000, 2000, 1600, 1000, 800, 500, 400, 320, 250, 200, 160, 100, 80, 50, 40, 20, 10)
- limited steps between off and fully on (25 at 8000Hz, 250 at 800Hz, 4000 at 50Hz)
software PWM
- stability depends on system activity, will be better on the four core Pi2 compared to single core Pis. Servos will jitter and LEDs will flash when the system is busy.
- infinite choice and range of frequencies
- infinite number of steps between off and fully on
