PWM Module API Manual#
Overview#
The K230 integrates two PWM hardware modules, each with three output channels. The output frequency of each module is adjustable, but the three channels share the same clock, while the duty cycle can be independently configured. Thus, channels 0, 1, and 2 share the same output frequency, and channels 3, 4, and 5 also share the same output frequency. For the I/O configuration of the channel outputs, refer to the IOMUX module.
API Introduction#
The PWM class is located in the machine module.
Example Code#
import time
from machine import PWM, FPIOA
CONSTRUCT_WITH_FPIOA = False
PWM_CHANNEL = 0
PWM_PIN = 42
TEST_FREQ = 1000 # Hz
# Initialize PWM with 50% duty
try:
if CONSTRUCT_WITH_FPIOA:
# Use FPIOA to configure pin multiplexing for PWM, then pass the channel
fpioa = FPIOA()
fpioa.set_function(PWM_PIN, fpioa.PWM0 + PWM_CHANNEL)
pwm = PWM(PWM_CHANNEL, freq=TEST_FREQ, duty=50)
else:
# Directly pass the pin number
pwm = PWM(PWM_PIN, freq=TEST_FREQ, duty=50)
except Exception:
print("FPIOA setup skipped or failed")
print("[INIT] freq: {}Hz, duty: {}%".format(pwm.freq(), pwm.duty()))
time.sleep(0.5)
# Test duty() getter and setter
print("[TEST] duty()")
pwm.duty(25)
print("Set duty to 25%, got:", pwm.duty(), "→ duty_u16:", pwm.duty_u16(), "→ duty_ns:", pwm.duty_ns())
time.sleep(0.2)
# Test duty_u16()
print("[TEST] duty_u16()")
pwm.duty_u16(32768) # 50%
print("Set duty_u16 to 32768, got:", pwm.duty_u16(), "→ duty():", pwm.duty(), "→ duty_ns():", pwm.duty_ns())
time.sleep(0.2)
# Test duty_ns()
print("[TEST] duty_ns()")
period_ns = 1000000000 // pwm.freq()
duty_ns_val = (period_ns * 75) // 100 # 75%
pwm.duty_ns(duty_ns_val)
print("Set duty_ns to", duty_ns_val, "ns (≈75%), got:", pwm.duty_ns(), "→ duty():", pwm.duty(), "→ duty_u16():", pwm.duty_u16())
time.sleep(0.2)
# Change frequency and re-check duty values
print("[TEST] Change frequency to 500Hz")
pwm.freq(500)
print("New freq:", pwm.freq())
print("Duty after freq change → duty():", pwm.duty(), "→ duty_u16():", pwm.duty_u16(), "→ duty_ns():", pwm.duty_ns())
time.sleep(0.2)
# Clean up
pwm.deinit()
print("[DONE] PWM test completed")
Constructor#
pwm = PWM(pin, freq=-1, duty=-1, duty_u16=-1, duty_ns=-1)
Parameters
pin: Pin object or pin number. The driver automatically sets the pin to PWM multiplexing. For pin mappings, refer to PWM Pin Multiplexing.freq: PWM output frequency (Hz). Default:-1(no change).duty: Duty cycle as a percentage of the period, range[0, 100]. Default:-1(no change).duty_ns: High-level duration in nanoseconds (ns). Default:-1(no change).duty_u16: High-level duration, range[0, 65535]. Default:-1(no change).
Only one of
duty,duty_ns, orduty_u16can be set at a time.
init Method#
PWM.init(freq=-1, duty=-1, duty_u16=-1, duty_ns=-1)
Parameters
Same as Constructor.
deinit Method#
PWM.deinit()
Release the PWM channel resources.
Parameters
None.
Returns
None.
freq Method#
PWM.freq([freq])
Get or set the PWM output frequency.
Parameters
freq: Optional. If provided, sets the frequency; otherwise, returns the current frequency.
Returns
Current frequency (if no argument) or None.
duty Method#
PWM.duty([duty])
Get or set the duty cycle (percentage).
Parameters
duty: Optional. If provided, sets the duty cycle; otherwise, returns the current value.
Returns
Current duty cycle (if no argument) or None.
duty_u16 Method#
PWM.duty_u16([duty_u16])
Get or set the duty cycle (16-bit value).
Parameters
duty_u16: Optional. If provided, sets the duty cycle; otherwise, returns the current value.
Returns
Current duty cycle (if no argument) or None.
duty_ns Method#
PWM.duty_ns([duty_ns])
Get or set the duty cycle (nanoseconds).
Parameters
duty_ns: Optional. If provided, sets the duty cycle; otherwise, returns the current value.
Returns
Current duty cycle (if no argument) or None.
PWM Pin Multiplexing#
PWM Channel |
Available Pins |
|---|---|
PWM0 |
GPIO42, GPIO54, GPIO60 |
PWM1 |
GPIO43, GPIO55, GPIO61 |
PWM2 |
GPIO7, GPIO46, GPIO56 |
PWM3 |
GPIO8, GPIO47, GPIO57 |
PWM4 |
GPIO9, GPIO52, GPIO58 |
PWM5 |
GPIO25, GPIO53, GPIO59 |