suggested add:

byte WLED = 13;

else you get:

Arduino: 1.8.5 (Linux), Board: "Arduino Nano, ATmega328P"

/home/pi/Arduino/libraries/SoftPWM/examples/SoftPWM_Wiring_HeartBeat/SoftPWM_Wiring_HeartBeat.pde: In function 'void setup()':
SoftPWM_Wiring_HeartBeat:8: error: 'WLED' was not declared in this scope
SoftPWMSet(WLED, 0);
^
/home/pi/Arduino/libraries/SoftPWM/examples/SoftPWM_Wiring_HeartBeat/SoftPWM_Wiring_HeartBeat.pde: In function 'void loop()':
SoftPWM_Wiring_HeartBeat:18: error: 'WLED' was not declared in this scope
SoftPWMSet(WLED, 255);
^
exit status 1
'WLED' was not declared in this scope

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

"on" is not fully "on", i.e. pwm of 255 have a short period of 0

This is how i patched it to work for my application (DC motor - h-bridge with "break" and "coast" ):
Note: My "h-bridge" ic require "full width high" for a "break" and "full width low" for a "coast"

What I did is:

1. Reset high and low when "++_isr_softcount == 0"
2. Skip "hit width" validation test for "checkval == 0" and "checkval == 255"

see the modified interrupt function below:

{
  uint8_t i;
  int16_t newvalue;
  int16_t direction;

  if (++_isr_softcount == 0)
  {
    // set all channels high - let's start again
    // and accept new checkvals
    for (i = 0; i < SOFTPWM_MAXCHANNELS; i++)
    {
      if (_softpwm_channels[i].fadeuprate > 0 || _softpwm_channels[i].fadedownrate > 0)
      {
        // we want to fade to the new value
        direction = _softpwm_channels[i].pwmvalue - _softpwm_channels[i].checkval;

        // we will default to jumping to the new value
        newvalue = _softpwm_channels[i].pwmvalue;

        if (direction > 0 && _softpwm_channels[i].fadeuprate > 0)
        {
          newvalue = _softpwm_channels[i].checkval + _softpwm_channels[i].fadeuprate;
          if (newvalue > _softpwm_channels[i].pwmvalue)
            newvalue = _softpwm_channels[i].pwmvalue;
        }
        else if (direction < 0 && _softpwm_channels[i].fadedownrate > 0)
        {
          newvalue = _softpwm_channels[i].checkval - _softpwm_channels[i].fadedownrate;
          if (newvalue < _softpwm_channels[i].pwmvalue)
            newvalue = _softpwm_channels[i].pwmvalue;
        }

        _softpwm_channels[i].checkval = newvalue;
      }
      else // just set the channel to the new value
        _softpwm_channels[i].checkval = _softpwm_channels[i].pwmvalue;

      // now set the pin low (checkval == 0x00) otherwise high 
      if (_softpwm_channels[i].checkval == 0x00)
      {
        if (_softpwm_channels[i].polarity == SOFTPWM_NORMAL)
          *_softpwm_channels[i].outport &= ~(_softpwm_channels[i].pinmask);
        else
          *_softpwm_channels[i].outport |= _softpwm_channels[i].pinmask;
      }
      else
      {
        if (_softpwm_channels[i].polarity == SOFTPWM_NORMAL)
          *_softpwm_channels[i].outport |= _softpwm_channels[i].pinmask;
        else
          *_softpwm_channels[i].outport &= ~(_softpwm_channels[i].pinmask);
      }
    }
  }

  for (i = 0; i < SOFTPWM_MAXCHANNELS; i++)
  {
    if (_softpwm_channels[i].pin >= 0) // if it's a valid pin
    {
      // skip hit on checkval 0 and 255
      if (_softpwm_channels[i].checkval != 0x00 && _softpwm_channels[i].checkval != 0xFF)
      {
        if (_softpwm_channels[i].checkval == _isr_softcount) // if we have hit the width
        {
          // turn off the channel
          if (_softpwm_channels[i].polarity == SOFTPWM_NORMAL)
            *_softpwm_channels[i].outport &= ~(_softpwm_channels[i].pinmask);
          else
            *_softpwm_channels[i].outport |= _softpwm_channels[i].pinmask;
        }
      }
    }
  }
}

I would like to activate multiple pins at once using soft pwm...

maybe the ability to pass an array instead of a single value?

Would this be possible?

The library works with Arduino Nano and Teensy (AVR/ARM) but not with EVERY boards (MEGAAVR).
When compiling, following error is given...

In file included from Arduino\libraries\SoftPWM\SoftPWM.cpp:44:0:
Arduino\libraries\SoftPWM\SoftPWM.cpp: In function 'void SoftPWMBegin(uint8_t)':
Arduino\libraries\SoftPWM\SoftPWM_timer.h:39:3: error: 'TIFR2' was not declared in this scope
TIFR2 = (1 << TOV2); /* clear interrupt flag */ \

even if I set the PWM to 255 the LED doesn't go off entirely. Its always lighting a bit! What can be the reason? I used a sink configuration with the ATMEGA GPIO to GND.

Hi there!
Is there an option to increase the frequency of the PWM signal? I'm trying to control small DC motors using this library, but there are significant vibrations going on to the motor with using the PWM. I suppose it is cause of the low frequency of the PWM signal. If yes, how can I do that?

PWM 255 as well as digitalWrite(PIN,HIGH) isn't HIGH any more.
Now there is a PWM spike on the signal. Seems that PWM 254 is the maximum HIGH level now.
LOW Level works (as mentioned within the README.md "True zero level, i.e. off == off").
HIGH Level is not mentioned :-)
I really appreciate the purpose of this library.

How to get this running on an ATtiny85 or ATtiny167 with no Timer2?

Hello,

Would it be possible to control more than 20 pins (I'd need 24 pins) on Mega2560?
I don't have it yet so I can't test, just want to know if possible and how.

Thanks!

Arduino: 1.8.12 (Mac OS X), Board: "ChipKit uC32"

RoomControlCode:2:10: fatal error: SoftPWMServo.h: No such file or directory
#include <SoftPWMServo.h>
^~~~~~~~~~~~~~~~
compilation terminated.
exit status 1
SoftPWMServo.h: No such file or directory

I wanted to use the library in a sketch including the IRremote library. Both librarys dont anymore as soon as they are enabled using irrecv.enableIRIn(); respectively SoftPWMBegin();.

I can assume some reasons for that behavior, but I am devinitely not able to tear down the exact reason.

Counld someone provide an example of using softpwm to control a servo? I don't know how to do it correctly. Many thanks.

Hi, the sample shows me the following error message:
libraries\SoftPWM\SoftPWM.cpp:41:10: fatal error: avr/io.h: No such file or directory
#include <avr/io.h>
^~~~~~~~~~
compilation terminated.
exit status 1

anything additional that needs to be considered?
thanks

Hi Brett
I like your SoftPWM-library for arduino a lot. Just today I found out, that millis() stops working, as soon as more than 4 LEDs are controlled using our library. I wasn't able to find a solution to that problem. Do you have an idea?
Best regards,
Dani

I used your example-code (), which uses 8 LEDs:
When checking with the serial monitor, I get constantly

26
26
26

Here is the code that doesn't work:

#include <SoftPWM.h>

#define DELAY 100
uint8_t leds[8] = {11,12,13,18,17,16,15,10};

void setup()
{
  Serial.begin(57600);
  SoftPWMBegin();

  for (int i = 0; i < 8; i++)
    SoftPWMSet(leds[i], 0);

  SoftPWMSetFadeTime(ALL, 50, 400);
}

void loop()
{
  int i;
  Serial.println(millis());
  for (i = 0; i < 7; i++)
  {
    SoftPWMSet(leds[i+1], 255);
    SoftPWMSet(leds[i], 0);
    delay(DELAY);
  }

  delay(400);

  for (i = 7; i > 0; i--)
  {
    SoftPWMSet(leds[i-1], 255);
    SoftPWMSet(leds[i], 0);
    delay(DELAY);
  }
  delay(400);
}

As soon as I change the code, so that it uses only 4 LEDs, it works as expected:

3014
5851
8695

Here is the code that works:

#include <SoftPWM.h>

#define DELAY 100
uint8_t leds[8] = {11,12,13,18,17,16,15,10};

void setup()
{
  Serial.begin(57600);
  SoftPWMBegin();

  for (int i = 0; i < 4; i++)
    SoftPWMSet(leds[i], 0);

  SoftPWMSetFadeTime(ALL, 50, 400);
}

void loop()
{
  int i;
  Serial.println(millis());
  for (i = 0; i < 3; i++)
  {
    SoftPWMSet(leds[i+1], 255);
    SoftPWMSet(leds[i], 0);
    delay(DELAY);
  }

  delay(400);

  for (i = 3; i > 0; i--)
  {
    SoftPWMSet(leds[i-1], 255);
    SoftPWMSet(leds[i], 0);
    delay(DELAY);
  }
  delay(400);
}

Hey,
I was wondering what exact pwm frequence the lib generates on a Arduino Mini with a Atmel 328p?

The lib compiles fine on Arduino CREATE but fails to upload.
It is NOT a CREATE problem but appears to be with the samples.