Pin 0 on A-Star 328PB Micro Doesn't Work about arduino-ledfader

[jgillick]

This is an odd one. What happens when you try to use it? I assume the LED doesn't come on at all?

Here's my theory: The library doesn't set the pin output mode itself and D0 is by default RX, which would be an input pin. Try this line in the setup() method:

pinMode(0, OUTPUT);

I don't think it has anything to do with the line you referenced in the header. That's just a default initialization and if you pass the pin number explicitly, that will be ignored.

[RossAWaddell]

Unfortunately, that didn't work. I even added:

UCSR0B = 0;

but that didn't help, either. And yes, the LED doesn't come on at all.

EDIT: Also, regular analogWrite(0,255); works, as does other LED libraries like jLed.

[jgillick]

That's really odd. Offhand I'm not sure why that would happen. I'll see if I have any Atmega 328PB chips lying around I can try this on.

[jgillick]

Just out of curiosity, does led.set_value(125); set the LED to half brightness?

[RossAWaddell]

Same result - the LED does not light.

#define LED_PIN 0
LEDFader led;

void setup() {
  led = LEDFader(LED_PIN);
  led.set_value(125);
}

void loop() {
  led.update();
}

[jgillick]

Ah ha! I think I found the problem:
https://github.com/jgillick/arduino-LEDFader/blob/master/LEDFader.cpp#L30

The code is first checking if the pin has been set. Well pin 0 is equivalently false. You can remove any of those lines. I'll try to update the library soon, but would also take a pull request if someone else wanted to take a stab at it. The library needs to be initialized with a pin, so those checks are likely moot.

[RossAWaddell]

That's definitely the issue - if I comment out:

   // No pin defined
  //if (!pin) {
  //    return;
  //}

then all works as expected.

I would happily do a pull request for this, but wanted to check with you first - is it sufficient to just remove those checks from all functions, or would it be better to initialize the class with a signed int instead, as in:

// Create a new LED Fader for a pin
    LEDFader(int pwm_pin=-1);

Then the checks can remain, but like this:

   // No pin defined
  if (pin == -1) {
      return;
  }

[jgillick]

I think it's safe to remove those checks entirely. A pin must be defined at initialization, so the checks are really unnecessarily. Thank you!

[RossAWaddell]

Ok, I’ll remove them and submit a pull request.

[RossAWaddell]

Done

[jgillick]

Great. Did you submit a pull request?

[RossAWaddell]

I did, although this is my first Github pull request. Do you not see it?

[jgillick]

It would show up here:
https://github.com/jgillick/arduino-LEDFader/pulls

Can you send me a link to it?

[RossAWaddell]

https://github.com/RossAWaddell/arduino-LEDFader

…

On Jan 16, 2020, at 6:26 PM, Jeremy Gillick ***@***.***> wrote: It would show up here: https://github.com/jgillick/arduino-LEDFader/pulls <https://github.com/jgillick/arduino-LEDFader/pulls> Can you send me a link to it? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#28?email_source=notifications&email_token=AHCVEZBYRQSKMUIWVCZTU2LQ6DUIVA5CNFSM4JOGRTDKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEJF5FLA#issuecomment-575394476>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AHCVEZBUBEV44TQUMTKDKYLQ6DUIVANCNFSM4JOGRTDA>.

[RossAWaddell]

It is showing up now under Pull requests.

[jgillick]

Got it and merged! Thanks @RossAWaddell, I really appreciate the help on this one.