SAMD21 keep pins low on start

Other Hardware 3rd Party Boards
1

Hi,

I have a problem that my SAMD21 switch on Portb3 for a short time (ms) during start up.
I'm using Arduino M0 Pro as a bootloader. The problem is that on this pin have a relais to switch off the whole circuit. So when starting up it switching off right now because of that pulse on portb3.
How can I prevent this?

That's the text program so far:

#define RELAIS_RESET_PIN 30 // PB3, 48 an IC
void setup() {
pinMode(RELAIS_RESET_PIN, OUTPUT);digitalWrite(RELAIS_RESET_PIN, LOW);
}

void loop() {
}

2

Try changing this:

timtailors:

#define RELAIS_RESET_PIN 30 // PB3,  48 an IC

void setup() {
  pinMode(RELAIS_RESET_PIN, OUTPUT);digitalWrite(RELAIS_RESET_PIN, LOW);
}

void loop() {
}




to this:

#define RELAIS_RESET_PIN 30 // PB3,  48 an IC
void setup()
{
  digitalWrite(RELAIS_RESET_PIN, LOW);
  pinMode(RELAIS_RESET_PIN, OUTPUT);
}

void loop() {
}

And with 76 posts on the forum you should know how to use code tags...