wiring_digital.c, function turnOffPWM(uint8_t timer) does not switch off properly

[gonzoveliki]

Attention: This BUG concerns only AVR based platforms, standard variant, and not the new ARM based ones like DUE and Teensy. It is also doesn't affect Teensy 2.0 which is featuring AVR32U4 and is using different code for digital_wiring...

As I menioned and described here:
http://forum.arduino.cc/index.php?topic=252700.msg1789311
There is core bug in wiring_digital.c that has been there for a long time.
All AVR platforms using "standard" arduino core are affected,
It is obvious only with PWM mode on pin 5 on UNO,
and whichever pin is attached with TIMER0B on other boards.
Problem occurs only when a PWM is used once on that pin,
and after that can't be switched back to a solid bi-level digital.
digitalWrite, pinMode, analogWrite(5,0) or analogWrite(5,255)
are not helping either.

Solution is quite simple:
in file "wiring_digital.c"

search for
"#if defined(TIMER0B) && defined(COM0B1)"
and replace with
"#if defined(TCCR0A) && defined(COM0B1)"

That's all, regards, I am glad helping this solved.

Regards

[matthijskooijman]

Hmm, I'm confused. I think the code you are talking about is:

#if defined(TIMER0B) && defined(COM0B1)
case TIMER0B: cbi(TCCR0A, COM0B1); break;
#endif
#if defined(TCCR2A) && defined(COM2A1)
case TIMER2A: cbi(TCCR2A, COM2A1); break;
#endif

Here, the ifdefs seem inconsistent - there is one that uses TIMER0B,
while all others use TCCR2A.

Fixing that seems sane (the same thing seems to occur in the ide-1.5.x
branch.

However, I'm not sure how this inconsistency can cause the behaviour you
are describing (which I understand as "turnOffPWM is not working for the
TIMER0B pin"). This could happen if the #if checks are too strict and
cause the relevant case to be left out during compilation. However,
looking at Arduino.h, it seems that TIMER0B is always defined,
so the fix you suggest should not cause the case to be included where it
was previously excluded.

Any more insight on this?