MicroPython Forum (Archive)

Posted: **Wed Feb 05, 2020 10:50 pm**

Why when i use Pin.on() my led turn off and when i use Pin.off() my led turn on??

this is the last code i used before this issue:

Code: Select all

from machine import Pin, PWM
from time import sleep
import re

pin25 = Pin(25)

def cancion(tempo, n, *args):
    pwm25 = PWM(pin25, 0, 900)
    negra = float(60/tempo)
    semicorchea = negra/4
    corchea = negra/2
    blanca = negra*2
    for arg in args:
        nota = re.search(r'\(?([A-Za-z]+)\)?', arg).group(1)
        modificador = arg.replace(nota, "")
        
        if len(modificador) > 1:
            if modificador[0] == "-":
                n -= 1
            elif modificador [0] == "+":
                n += 1
        
        if nota == "do":
            pwm25.freq(33*2**n)
        elif nota == "re":
            pwm25.freq(37*2**n)
        elif nota == "mi":
            pwm25.freq(41*2**n)
        elif nota == "fa":
            pwm25.freq(44*2**n)
        elif nota == "sol":
            pwm25.freq(49*2**n)
        elif nota == "la":
            pwm25.freq(55*2**n)
        elif nota == "si":
            pwm25.freq(62*2**n)
        elif nota == "sl":
            pwm25.freq(0)
        
        tiempo = int(arg[-1])
        if tiempo == 0:
            sleep(semicorchea)
        elif tiempo == 1:
            sleep(corchea)
        elif tiempo == 2:
            sleep(negra)
        elif tiempo == 3:
            sleep(blanca)
    
    pwm25.deinit()

cancion(100, 6, "mi0", "mi1", "mi0", "sl0", "do0", "mi1", "sol2", "-sol2",
        "do1", "sl0", "-sol0", "sl1", "-mi1")

sleep(1)

cancion(80, 4, "mi0", "mi1", "mi0", "sl0", "do0", "mi1", "sol2", "-sol2",
        "do1", "sl0", "-sol0", "sl1", "-mi1")

sleep(1)

cancion(120, 5, "do1", "re1", "mi1", "fa1", "sol1", "la1", "si1", "+do1")
cancion(140, 6, "do1", "re1", "mi1", "fa1", "sol1", "la1", "si1", "+do1")
cancion(160, 7, "do1", "re1", "mi1", "fa1", "sol1", "la1", "si1", "+do1")
cancion(60, 7, "+mi3")

sleep(1)

cancion(200, 5, "-do1", "do1", "+do1")

it was for make music with a cellphone speaker.

i have esp32 wroom devkit 1

Posted: **Thu Feb 06, 2020 1:20 am**

This is pretty common -- it depends on how the LED is wired, but if it goes Vcc--LED--resistor--pin, then turning off the pin will turn on the LED. People do this for a variety of reasons, sometimes because some microcontrollers can sink more current than they can source, but also sometimes it just makes the PCB design easier.

Here's an image showing the two configurations -- http://inside.mines.edu/~coulston/cours ... mg/led.jpg -- yours is the one on the right. (From http://inside.mines.edu/~coulston/cours ... ure08.html )

Posted: **Fri Feb 07, 2020 1:32 am**

thank you very much!!!

MicroPython Forum (Archive)

on() is off() and off() is on()

on() is off() and off() is on()

Re: on() is off() and off() is on()

Re: on() is off() and off() is on()