Very simple code issue on DUE

Projects Programming
1

This code

void setup() 
{
  pinMode(12, OUTPUT);
  Serial.begin(9600);
  Serial.print("test");
}

void loop() 
{
  analogWrite(12, 1);
  delayMicroseconds(500);
  analogWrite(12, 255);
  delayMicroseconds(500);
}

produces attached scope output, WHY :o ?

I am sure it's a simple answer :wink:

Steve

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20170301_101227.jpg
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2

Yep looks good check the freq of the PWM you are using!

Mark

3

check the freq of the PWM you are using!

If it's compatible with the AVR, the PWM frequency is about 1kHz. So delaying 500us between calls to analogWrite() will interrupt/reset the PWM (or something) before even one cycle has completed. I don't think it's 'defined' what happens in that case, and it doesn't surprise me that it's weird.

4

OK think I am starting to understand, has anyone got a good example of how to set a LED brightness and then change it without causing a reset etc.

What I want to do it pulse the LED as fast as possible and with different brightness's

So this sort of thing, output these brightness's as quickly as possible

1%
50%
34%
2%
95%
25%

Thanks

Steve

5

Sorted bit banging it :slight_smile:

Thx

Steve