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PWM Module API Manual

Overview

The K230 contains two PWM hardware modules internally, 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 adjusted independently. Therefore, channels 0, 1, and 2 have the same output frequency, and channels 3, 4, and 5 also have the same output frequency. For the I/O configuration of channel output, please 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:
        # 使用FPIOA 配置引脚复用为PWM, 构造时传入 channel
        fpioa = FPIOA()
        fpioa.set_function(PWM_PIN, fpioa.PWM0 + PWM_CHANNEL)
        pwm = PWM(PWM_CHANNEL, freq=TEST_FREQ, duty=50)
    else:
        # 直接传入引脚
        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)

# 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)

# 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)

# 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 alternate function. For the correspondence between specific pins and PWM, please refer to Pin Multiplexing

• freq: PWM channel output frequency

• duty: PWM channel output duty cycle, representing the percentage of high level in the entire period, with a value range of [0, 100]

• duty_ns: The time of high level output from the PWM channel, in ns

• duty_u16: The time of high level output from the PWM channel, with a value range of [0, 65535]

Only one of duty, duty_ns, and duty_u16 can be set.

init Method

PWM.init(freq = -1, duty = -1, duty_u16 = -1, duty_ns = -1)

Parameters

Refer to Constructor

deinit Method

PWM.deinit()

Release the resources of the PWM channel.

Parameters

None

Return Value

None

freq Method

PWM.freq([freq])

Get or set the output frequency of the PWM channel.

Parameters

• freq: PWM channel output frequency, optional parameter. If no parameter is passed in, the current frequency is returned.

Return Value

Returns the output frequency of the current PWM channel or empty.

duty Method

PWM.duty([duty])

Get or set the output duty cycle of the PWM channel.

Parameters

• duty: PWM channel output duty cycle, optional parameter. If no parameter is passed in, the current duty cycle is returned.

Return Value

Returns the output duty cycle of the current PWM channel or empty.

Return Value

None

duty_u16 Method

PWM.duty_u16([duty_u16])

Get or set the output duty cycle of the PWM channel.

Parameters

• duty_u16: PWM channel output duty cycle, optional parameter. If no parameter is passed in, the current duty cycle is returned.

Return Value

Returns the output duty cycle of the current PWM channel or empty.

Return Value

None

duty_ns Method

PWM.duty_ns([duty_ns])

Get or set the output duty cycle of the PWM channel.

Parameters

• duty_ns: PWM channel output duty cycle, optional parameter. If no parameter is passed in, the current duty cycle is returned.

Return Value

Returns the output duty cycle of the current PWM channel or empty.

Return Value

None

PWM Pin Multiplexing

PWM	Alternative 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