question of digitalPulse()

[espruino-discuss3]

Posted at 2015-07-07 by Long

I use the 'digitalPulse()' on the borad "nucleo 411" like this:

>while(1){digitalPulse(A5,1,[1000,1000]);}

but it comes with the problem:

=undefined
Uncaught InternalError: Timeout on Utility Timer
 at line 1 col 39
while(1){digitalPulse(A5,1,[1000,1000]);}

how can I solve the problem ?

[gfwilliams]

Posted at 2015-07-07 by @gfwilliams

digitalPulse is asynchronous - it doesn't wait for the last pulse to finish. The error is because you're just queuing up a whole load of 1 second pulses and Espruino thinks something has gone wrong because the queue is taking too long to empty.

If you're trying to do a square wave, why not use the built-in PWM hardware, which would be very accurate?

analogWrite(A5, 0.5, {freq:0.5});

Or you could just use setInterval:

setInterval(function() {
  digitalPulse(A5,1,1000)­;
}, 2000);

If you absolutely want to use digitalPulse, you could just ensure you wait for the queue to end first with digitalPulse(A5);