rpi_hardware_pwm

Access the hardware PWM of a RaspberryPi with Python. More lightweight than alternatives.

Installation

Installation is a two step process:

1. On the Raspberry Pi, add dtoverlay=pwm-2chan to /boot/config.txt. Reboot your Raspberry Pi. This defaults to GPIO_18 as the pin for PWM0 and GPIO_19 as the pin for PWM1.
   • Alternatively, you can change GPIO_18 to GPIO_12 and GPIO_19 to GPIO_13 using dtoverlay=pwm-2chan,pin=12,func=4,pin2=13,func2=4.
   • You can check everything is working on running lsmod | grep pwm and looking for pwm_bcm2835
2. Install this library: sudo pip install rpi-hardware-pwm

Examples

from rpi_hardware_pwm import HardwarePWM

pwm = HardwarePWM(0, hz=60)
pwm.start(100) # full duty cycle

pwm.change_duty_cycle(50)

pwm.stop()

History

The original code is from jdimpson/syspwm, We've updated it to Python3 and made it look like the RPi.GPIO library's API (but more Pythonic than that.), and we use it in Pioreactor bioreactor system.