I need a PWM signal of 25KHz and duty cicle 0-100%. It must be "hardware" becase I don't want to bother the CPU with that. The ony way I found to do that in Python is by using ppigpio library. But I never used before and I don't know how to set it up. As far as I understand there is true hardware pwm and hardware-timed pwm. But I don't know which instructions stars on type and which starts the other. Can you show me a basic example ?
Edit: is this the right way to do it ?
import pigpio
import time
Set the GPIO pin for PWM
gpio_pin = 18
Set the PWM frequency (25 kHz)
pwm_frequency = 25000
Set the PWM duty cycle (75%)
pwm_duty_cycle = 750000 # 75% of the range (0-1000000)
Initialize the pigpio library
pi = pigpio.pi()
if not pi.connected:
print("Unable to connect to pigpio daemon. Exiting.")
exit()
try:
# Set the PWM frequency and duty cycle using hardware_PWM
pi.hardware_PWM(gpio_pin, pwm_frequency, pwm_duty_cycle)
# Run the PWM for a certain duration (e.g., 10 seconds)
time.sleep(10)
finally:
# Stop PWM and cleanup
pi.hardware_PWM(gpio_pin, 0, 0) # Set duty cycle to 0 to stop PWM
pi.stop()
Edit2: I also tried this, but it says "bad PWM frequency":
from gpiozero import PWMOutputDevice
import time
PWM_PIN = 18 # Change this to the GPIO pin you want to use
PWM_FREQUENCY = 25000 # 25 kHz
PWM_DUTY_CYCLE = 0.5 # 50%
pwm = PWMOutputDevice(PWM_PIN, frequency=PWM_FREQUENCY)
try:
while True:
print('Speed: 100 %')
pwm.value = 1
time.sleep(20)
print('Speed: 50 %')
pwm.value = 0.5
time.sleep(20)
except KeyboardInterrupt:
pass
finally:
pwm.value = 0 # Set PWM duty cycle to 0
print("\nProgram terminated by user. PWM stopped.")
