Circuitpython Pwm - Adafruit Feather M4 Express Manual

CircuitPython PWM

Your board has
pulseio
train" type devices like DHT22 and Infrared.
Nearly every pin has PWM support! For example, all ATSAMD21 board have an A0 pin which is 'true' analog out and
does not have PWM support.
PWM with Fixed Frequency
This example will show you how to use PWM to fade the little red LED on your board.
Copy and paste the code into code.py using your favorite editor, and save the file.
import time
import board
import pulseio
led = pulseio.PWMOut(board.D13, frequency=5000, duty_cycle=0)
while True:
for i in range(100):
# PWM LED up and down
if i < 50:
led.duty_cycle = int(i * 2 * 65535 / 100)
else:
led.duty_cycle = 65535 - int((i - 50) * 2 * 65535 / 100)
time.sleep(0.01)
Create a PWM Output
led = pulseio.PWMOut(board.D13, frequency=5000, duty_cycle=0)
Since we're using the onboard LED, we'll call the object
the LED pin to use.
D13
Main Loop
The main loop uses
range()
and when the range is above 50, it PWMs the brightness down. This is how it fades the LED brighter and dimmer!
The is needed to allow the PWM process to occur over a period of time. Otherwise it happens too quickly
time.sleep()
for you to see!
PWM Output with Variable Frequency
Fixed frequency outputs are great for pulsing LEDs or controlling servos. But if you want to make some beeps with a
piezo, you'll need to vary the frequency.
The following example uses
To use with any of the M0 boards, no changes to the following code are needed.
© Adafruit Industries
support, which means you can PWM LEDs, control servos, beep piezos, and manage "pulse
to cycle through the loop. When the range is below 50, it PWMs the LED brightness up,
to make a series of tones on a piezo.
pulseio
https://learn.adafruit.com/adafruit-feather-m4-express-atsamd51
# Up
# Down
, use
led pulseio.PWMOut
to create the output and pass in
Page 119 of 183