Sujet : Re: Calculate frequencey and pulse width?
De : jansencomplex (at) *nospam* gmail.com (Samson)
Groupes : comp.sys.raspberry-piDate : 02. Nov 2024, 07:53:23
Autres entêtes
Message-ID : <lom0j3FjeavU1@mid.individual.net>
References : 1 2
User-Agent : Mozilla Thunderbird
Den 01-11-2024 kl. 22:03 skrev Lawrence D'Oliveiro:
On Fri, 1 Nov 2024 07:19:07 +0100, Samson wrote:
[how] do i calculate the frquency and pulse width?
Let’s see, cycle duration = 1 ÷ frequency, so pulse width must be duty
cycle × cycle duration.
What do I win?
Sorry here are more info. The pico limits PWM 8 Hz and up pulse width 1 - 100 % .
I have this program and i works i understand how it works.
my problem was understanding >> dup[delay] ?
=====
# Example using PIO to blink an LED and raise an IRQ at 1Hz.
import time
from machine import Pin
import rp2
@rp2.asm_pio(set_init=rp2.PIO.OUT_LOW)
def blink_1hz():
# Cycles: 1 + 1 + 6 + 32 * (30 + 1) = 1000
irq(rel(0))
set(pins, 1)
set(x, 31) [5]
label("delay_high")
nop() [29]
jmp(x_dec, "delay_high")
# Cycles: 1 + 7 + 32 * (30 + 1) = 1000
set(pins, 0)
set(x, 31) [6]
label("delay_low")
nop() [29]
jmp(x_dec, "delay_low")
# Create the StateMachine with the blink_1hz program, outputting on Pin(25).
sm = rp2.StateMachine(0, blink_1hz, freq=2000, set_base=Pin(25))
# Set the IRQ handler to print the millisecond timestamp.
sm.irq(lambda p: print(time.ticks_ms()))
# Start the StateMachine.
sm.active(1)